1030 Carbon Steel: A softer form of steel typically used in iron forgings. It is more malleable than other stainless steels used in golf clubs making it easier to hand work during forging. 8620 is another common example of carbon steel.
15-5 Stainless: A stronger lighter alloy of stainless as compared to 17-4 stainless. 15-5 is commonly used in thinner-walled fairway and hybrid clubs. It is composed of 75% iron, 5% nickel and 15% Chromium.
17-4 Stainless Steel: A type of stainless steel used in iron head and all metal wood head construction. In composition, 17-4 is no more than 0.07% carbon, between 15 and 17% chromium, 4% nickel, 2.75% copper, and 75% iron and trace elements.
18-8 Stainless Steel: A type of stainless steel sometimes used in the manufacture of iron and putter heads. Its composition is no more than 0.08% carbon, 18-20% chromium, 8-11% nickel, with the remainder being iron and a few trace elements. As 18-8 cannot be treated to make it harder, it is best used only on non-offset iron heads with thicker hosels.
431 Stainless Steel: A type of stainless steel used in iron and putter head construction. In composition, it is not more than 20% carbon, 15-17% chromium, and 1.25-2.5% nickel, with the remainder being iron and a few trace elements.
6-4 Titanium: A grade of titanium used in wood head manufacture. Its technical formula is 6Al-4V, indicating that its composition is 90% titanium, 6% aluminum and 4% vanadium. Its high strength to weight ratio allows it to be used to effectively for thin-walled face inserts.
Allen Wrench: Type of wrench used to remove or install screws in adjustable-weighted clubheads. It is also called a hex wrench.
Alloy: Any combination of metals used to produce a club head or shaft. Alloys may contain aluminum, steel, beryllium, nickel, copper, titanium, or any number of other metals in varying combinations.
Aluminum Wood Head: A type of metal wood head constructed primarily from aluminum alloys through a die casting process. Aluminum woods are generally utilized by beginning players due to their lower price. They typically are not as durable as stainless steel woods. They may also be known as aluminum alloy heads.
Aluminum Shafts: Golf shafts formed from aluminum tubing, used primarily in the 1960’s and early 70’s. They did not gain popularity due to their softer feel and due to them being less durable than steel shafts. Today, they are used primarily in putters.
Appendix II (Design of Clubs): United States Golf Association (USGA) Rule Book section dealing specifically with regulations for the design of golf clubs.
Ascending Weight Technology: The concept of using progressively heavier shafts in the set as the club becomes shorter. The lighter shafts are used in the long irons for added club head speed and distance, while the use of heavier shafts in the shorter irons to promote control.
Autoclave: A pressurized heating device used for shaft construction. The autoclave is a heat treating chamber which applies pressure and high temperature to a material in order to cure it.
Back Weight: A weight, usually brass or aluminum attached to the back of a wooden, graphite or titanium wood head. Powerbilt popularized the use of back weights on their woods in the 1960’s and 70’s. The back weight is designed to move the center of gravity rearward to assist in getting the ball airborne.
Back weighting: The process of adding weight to the back (or rear) of a club head to move the center of gravity further from the face. It is also be done by adding weight to the butt end of the shaft to intentionally shift the balance point of the club closer to the hands. The latter is also known as counter balancing.
Backscrew: Steel pin or screw used to help secure a steel shaft to a wooden wood head. The backscrew is located on the back of the heel approximately 3/4″ from the sole of the club.
Backspin: The backward rotation of a golf ball in flight around a horizontal axis as caused by the club hitting the ball. Typically the more loft on a club, the more backspin will be imparted to the ball.
Balance Point: The point at which a shaft achieves equilibrium; the point at which a shaft’s weight is evenly distributed in both directions when rested on a single fulcrum point.
Balata: A natural or synthetic compound used as a cover material for balls. Characterized by a soft feel and high spin rate. Generally preferred by better players, balata balls are less durable than other types of balls.
Ball Size: The size of a USGA conforming ball must not be smaller than 1.680″ (42.67mm.)
Ball Weight: The weight of a USGA conforming ball must not be greater than 1.620 ounces avoirdupois (45.93 grams.)
Bend Point: The point of maximum bending on a shaft as measured by a compression test of the shaft on both the tip and butt ends.
Beryllium Copper (BeCu): An alloy used at one time to produce club heads, typically irons and wedges. The alloy is denser than stainless steel and is claimed to provide a softer feel by some players. Beryllium heads are easily identified by their copper coloration.
Beta-Titanium: An alloy of Titanium that is stronger and lighter than typical titanium allowing the walls of the head to be made thinner due to the higher strength of beta-titanium.
Bias: Term to describe the ball flight of a clubhead, such as draw, neutral or fade based upon the position of the weight distribution.
Big Butt Shaft: Any shaft with a butt size over .620″ is classed as a big (or large) butt shaft. A series of shafts made in the mid-to-late 1990’s had butt diameters ranging from .790″ to 0.865″ and requiring specific grips.
Big Tip Shaft: A shaft that fits into an oversize hosel club. A shaft larger than .350″ in a wood or .370″ in an iron is considered a big tip shaft. Certain manufacturers increase the diameter for either increased stability or strength.
BiMatrx: A shaft made by True Temper comprised
of a graphite body and steel tip section.
Bi-Metal: A club head constructed from two different materials. A common example is a stainless steel club head with a brass sole insert or brass sole rails.
Blade: The general term given to the striking face of any iron head.
Blade Style Head: The class of irons identified by their equal weight distribution. Blades are identified by their relatively smooth back shape. Blade style irons are popular among better players due to the increased feel and feedback they may provide. Blades are also known as muscle-back irons due to a possible concentration of weight directly behind the center of the club face.
Blade Length: The length from the outermost portion of the toe to the position on the sole where the shaft would touch the ground when measured at its proper lie angle.
Blade Height: The measurement of an iron head at the center of the face from the ground line to the top line.
Blind Bore: A bore configuration of wood head in which the shaft penetrates the bore to a point of 1/2″ from the sole of the club head.
Bore-Through: A hosel type in which the shaft penetrates through the sole of the club. Callaway? clubs are the most common examples of bore-through heads.
Bore Type: The bore configuration of a type of a wood head identifying the distance from the bottom of where the shaft seats to the ground line.
Boring: (Hosel Boring): The process, using a drill or drill press, of enlarging the hosel size (bore) of a wood, iron or putter.
Boron: A high strength element added to some graphite shafts to increase tip strength. It is a very expensive material, thus shafts containing boron tend to be more expensive.
Bounce: The angle created from the leading and trailing edges of the sole of a golf club. Wedges typically have the most bounce in a set of clubs, where the leading edge will be resting higher than the trailing edge with the club in the square position. Bounce helps these clubs go through sand and high grass easily.
Bubble Shaft: A composite shaft, proprietary to
TaylorMade that is designed to stabilize the club head at impact.
It features a recessed section just below the grip. It is also unique
in that the butt diameter of the shaft is .810″, requiring a special
Bubble Grip: The specialized type of grip that
must be used on a Bubble shaft.
Build-Up Tape: Masking tape applied to the butt section of the shaft to increase grip size. Two layers of masking tape (.038″ thick) will increase grip size @ 1/64.”
Bulge: The curvature of the face of a wood (or some hybrids) from heel to toe. Bulge aids in compensating for the draw and fade spin imparted on the ball when it is struck on the toe or heel side of the center of gravity.
Bushing Ferrule: A type of ferrule used to reduce the size of an oversize metal wood or iron hosel to a .335″ (wood) or .370″ (iron) diameter. The bushing ferrule is epoxied into the hosel; the shaft is then epoxied in place as in a normal shaft installation.
Butt (Shaft Butt): The large end of the shaft onto which the grip is installed.
Butt Cap: The end of the grip of a club. Also the plastic or rubber cap used in certain leather or Winn grip applications. (See also “End Cap.”)
Butt Diameter: Refers to the measurement of the larger end of the shaft (in inches) where the grip is to be installed. (For example, .580″ or .600″)
Butt Heavy: A type of shaft construction in which the butt section of the shaft is heavier than an equal length of the tip section. Most graphite shafts and parallel tip shafts are considered to be butt heavy shafts.
Butt Section: The parallel portion of the butt end of a shaft, normally down to the first step on steel shafts.
Butt Trim: Term applied when cutting a shaft from its butt end.
Butt Weight: The process of adding weight to the butt end of a shaft, either by wrapping it with lead tape or by installing a lead plug in the shaft. The “Butt Weight” is also the term given to the plug that may be placed into the shaft. (See also Back weighting or counter balancing)
Caliper: Measuring device used to accurately measure the diameters of shaft tips and butts as well as finished grip sizes.
Camber: The radius measurement of the sole of a club. A sole can be cambered from toe-to-heel, from front-to-back, or both.
Casting: See Lost Wax Investment casting.
Cavity Back: The design of an iron head in which the weight is distributed toward the perimeter of the head. Cavity backs are easily identified as having a recessed area on the back of the head.
Center of Gravity (CG): The point in a club head at which all of the points of balance intersect. CG is often mistakenly referred to as the “sweet spot.”
Center-Shafted: A type of hosel configuration, common in putters, in which the shaft enters the head toward the center. Bullseye-type putters are the best known examples of center-shafted putters.
Chamfer: Generic term used to describe the process of using a special tool to “countersink”, “radius” or “cone” the inside of a hosel of a club in order to help reduce a shear point between the shaft (particularly graphite) and the top of the head.
Characteristic Time (CT): Designed to measure the clubhead flexibility (or ‘spring-like’ effect) of a driving club. A steel weight is suspended on a pendulum and then released to strike the clubface. The amount of time these two objects are in contact is the basis for the test, and the conformance limit has been set at 239 microseconds, plus a test tolerance of 18 microseconds. Any golf club with a CT measurement exceeding 257 microseconds does not conform to the Rules of Golf. This test replaced the Coefficient of Restitution Test.
Chrome Plated Finish: Type of finish electrostatically applied to forged or cast carbon steel irons and identified by its high lustrous appearance.
Coefficient of Restitution (COR): The amount of energy put into a golf ball as compared to the amount of energy at (after) impact. The COR is the relation between rebound velocity and initial velocity. Putty would have a COR of 0. A perfectly elastic material has a COR of 1. Any golf club with a COR exceeding 0.83 does not conform to the Rules of Golf.
Component: Any of the parts used to assemble golf clubs, be they heads, shafts or grips.
Compression: The deflection a ball undergoes under a compressive load or loosely defined as the hardness of a ball. Identified by a number; a higher number indicates a ball that requires more force to compress it. Lower compression balls will flatten more when struck.
Compression Molded: A manufacturing method for graphite heads and face inserts in which layers of graphite are placed upon one another and heat cured to create the clubhead or insert.
CNC (Computer Numerically Controlled) Milling: A production method, usually used for putters, in which the entire head is milled from a soft block of metal. A computer controls the milling machine.
Conforming Ball: Any golf ball that is permitted for tournament and conforms to the USGA Rules of Golf as detailed in Appendix III.
Conforming Club: Any golf club that is permitted for tournament and conforms to use USGA Rules of Golf as detailed in Appendix II.
Constant Weight: A shafting concept in which all of the shafts in a given set weigh the same regardless of their length.
Core (Ball): Any one of various materials used inside the golf ball. A solid core ball utilizes a hard material inside the cover; a wound core ball typically has softer core covered by a series of windings and the cover.
Core Size (Grip): The internal diameter measurement of a grip. Typically core sizes match shaft butt sizes. For example, an M60 grip core will match with a .600″ shaft butt size and produce a standard size grip.
Counter Balance: The process of adding weight in the butt end of a shaft to achieve a specific swingweight and/or feel. Counter balancing will increase the overall weight of the club and shifts the center of gravity of the club closer to the hands.
Countersink: Generic term used to describe the process of using a special tool to “countersink”, “radius” or “cone” the inside of a hosel of a club in order to help reduce a shear point between the shaft (particularly graphite) and the top of the head.
Cover: Outside surface of a golf ball. The cover may be one of any number of materials, Surlyn?, Elastomer and balata being most common.
Crown: The upper portion of the head of a wood head or hybrid. It is the portion of the head most visible to the player at address.
Cubic Centimeters (cc’s): The units used to measure the volume of a club head, most commonly woods and hybrids. The measurement is generally made as a water displacement test whereby the head is immersed in water and the amount of water displaced equals the head’s volume.
Curved Shaft: A shaft, usually steel or aluminum, designed for use in no-hosel putters that features a bend or bends no more than 5″ from the shaft tip. The curved shaft tends to create offset and/or lie and possibly face balancing on putters with no hosels.
Cycles Per Minute (CPM): The common measurement units when discussing the frequency of a shaft.
Deflection: The comparative measure of the relative stiffness of a shaft as measured by securing a weight toward the tip of a shaft (club) and relating this to a known stiffness scale.
Deep Face: A club face that measures higher than average from the sole of the club to the crown. This is a relative measure; no specific measurement dimension is applied to the term deep f
ace. Deep face clubs tend to have a higher CG and thus may launch the ball on a lower trajectory.
Demo Clubs: Used for the purpose of trying out a clubhead designs or a known specification used as part of the fitting process.
Die-Cast: Process of club head production (primarily used with zinc or aluminum) in which heads are formed through the injection of material into a pre-formed die. This process is generally used on lower-priced heads.
Dimple: Depression on the cover of a ball providing lift, leading to distance and/or accuracy. Deeper dimples generally cause a lower ball flight; while shallow dimples add to trajectory. Large diameter dimples tend to make the ball stay in the air longer than do smaller diameter dimples.
Dimple Pattern: Arrangement of dimples on a ball. Various dimple patterns provide added lift, accuracy and/or distance. Patterns vary greatly from one manufacture to another.
Discrete Flex: A shaft having a specific flex designation. For example, True Temper’s Dynamic Gold S300 is a discrete flex shaft while the company’s parallel tipped Dynamic shaft is not.
Double-Cover Ball: A ball with a large central core surrounded by two thinner materials, one of them being the cover. The purpose of the additional cover is to add spin on shorter shots for control and to reduce spin on longer shots for distance.
Double-Sided Tape: Also known as “Two-Way” or “Grip” tape, a type of tape, with adhesive on both sides that is used along with a solvent to secure grips in place.
Drag: Wind resistance as a golf ball flies or resistance caused when a club contacts the ground or goes through grass.
Driver: Term given to the club that is typically used to hit the ball for the first shot on a par 4 or par 5 hole. It is the longest hitting club in the set.
Driving Iron: General term given to an iron club with little loft; typically the name for a #1 iron.
Droop (Shaft Droop): The dynamic flattening of a club head as caused by the club being swung and the shaft bending perpendicular to the ground line.
DSFI (Dynacraft Shaft Fitting Index): The industry’s first “apples-to-apples” method of shaft classification. The DSFI is a comparison of shaft characteristics based on actual test results of the cut frequency, torque, tip and butt deflections of the shaft and how they relate to a player’s swing speed and tempo. A DSFI “number” is given to each shaft tested in order to best match the shaft to a given player.
Dynamic Fitting: The preferred method of fitting in which the golfer undertakes a series of fitting tests while actually hitting balls.
Elastomer: Material used in the formation of golf balls, particularly by Titleist. Also, a variety of material used in the manufacture of Winn grips.
End Cap: The end of the grip of a club. Also the plastic or rubber cap used in certain leather or Winn grip applications. (See also “Butt Cap.”)
Extension: A piece of material inserted into the shaft butt to make the shaft longer. The extension, with a maximum of no more than 2″, may be made of wood, steel, aluminum, hard plastic or graphite.
Face Angle: The position of the clubface relative to the intended line of ball flight. A square face angle aligns directly at the target, an open face aligns to the right and a closed faces to the left of the target (assuming a right hand golfer).
Face Balanced: A putter that, when balanced toward the shaft tip, will exhibit the property of the putter face being parallel to the ground line. Face balanced putters tend to be favored by players who employ a straight back-straight through putting stroke.
Face Insert: The center portion of the face on a wooden, composite, or metal head, typically constructed from numerous types of materials depending upon the clubhead type. Effective with a 1992 USGA ruling, all types of woods, irons and putters may have face inserts.
Face Progression: The measurement from a shaft’s centerline to the leading edge of the club face.
Fat Shaft: A shaft, designed by Wilson that utilizes
an oversized tip design in an attempt to provide head/shaft stabilization
on off-center hits.
Ferrule: The decorative trim ring, usually black (It may have additional trim colors.), that is found directly on top of the hosel on many woods and irons.
Fiber (Fibre): Material usually comprised of layers of a paper or phenolic material used to make inserts for wooden woods.
Filament Winding: A method of composite shaft manufacture in which a continuous strands of material (typically graphite fiber) is wrapped around a mandrel to create a shaft. Filament wound shafts are often a bit more consistent than sheet wrapped models.
First Step: The step on a steel shaft closest to the tip of the shaft.
Flange: The part of the club head protruding rearward from the head. Mainly a term used when discussing putters, a “flange” is the part of the putter from behind the face to the very back of the head.
Flat Lie: The term given to an iron or a wood having a lie flatter than specification. For example, if the specification is 60 degrees, a 2 degree flat club would have a lie angle of 58 degrees.
Flat Line Frequency: A method of frequency matching in which all of the woods or irons in the set maintain the same frequency. When plotted on a graph, the frequencies appear as a straight line.
Flex: The common term given to the relative bending properties of a golf club shaft. Flex is usually identified by a letter: L for Ladies, A for Amateur, R for regular, S for Stiff and X for Extra Stiff.
Flow Weighting: A method of head design in which the positioning of the weight in the head moves across the head from one club to the next. For example, a #1 iron may have more weight concentrated on its toe, a #2 iron slightly less, and so on.
Forged Titanium: A method of wood head manufacture in which the body and sole of the head is formed (forged) from 100% (pure) titanium. The face and hosels of such woods are typically produced from 6-4 titanium. Forged titanium woods are less costly due to their ease of forming as well as their lower raw material cost.
Forging: The process of producing a golf club in which a piece of semi-malleable metal is subjected to a series of steps in which the club is literally pounded from a raw piece of metal into a clubhead in a combination of stamping dies and numerous hand operations. Forged heads are typically made of softer metals than are cast heads and require laborious hand finishing and chrome plating (irons) in order to produce a finished product.
Four Piece Ball: A golf ball constructed from four specific materials. There will be a central core surrounded by windings covered by a harder secondary cover (for distance) and a softer outer cover (for spin and feel.)
Four-Way Radius: The sole design of an iron or wood in which there is a measurable radius of the sole both from heel-to-toe and from the trailing edge to the leading edge.
Frequency: The number of oscillations of a golf shaft in a given time as seen when the tip is pulled down and the shaft vibrates in a specialized machine. Frequency is measured in cycles per minute (cpm’s.)
Frequency Analyzer: Specialized machine used to measure the frequencies of golf clubs and shafts.
Frequency Matching: The process of ensuring that all of the clubs in a given set are matched in some manner by their shaft frequency. Frequency matched clubs are said to be more consistent in both feel and performance.
Frequency Slope: The graph line formed when plotting the frequencies of the shafts in a set of clubs. A well-matched set will have a consistent slope; a non-matched set will show shafts that vary several cycles from their expected range.
Gear Effect: The effect, caused by face bulge, that tends to cause a ball hit toward the toe or heel side of face center to curve back to the intended target line.
Graphite: A synthetic material used for shaft and head production. It is produced through a series of heating steps to make soft, black carbon graphite filaments. Graphite fibers may differ greatly in strength and modulus.
Gooseneck: A general term given to a putter (or iron) that has an extremely offset hosel.
Grip Collar: Plastic collar used to secure the bottom of a leather grip.
Grip Core: The internal diameter of a grip as measured in thousandths. For example, a men’s grip with a .600″ core is labeled as M60.
Grip Mouth: The opening at the small end of the grip that is intended to fit over the butt end of the shaft. The mouth will contain a code (i.e. M58) indicating the size and type of grip (men’s grip to fit .580″ shaft.)
Grip Tape: A type of tape with adhesive on both sides that is to be used along with a solvent to secure grips into place. Also known as “Two-Way” or “Double-Sided” tape.
Ground Line: The term given to the flat surface on which a club head is placed to measure its specifications. It is the line running from the club face to back, perpendicular to the shaft centerline. Ground line may be loosely interpreted to mean the position the club is placed in on the ground as the player address a shot on the course as well.
Gunmetal finish: Black oxide type of finish applied to irons or most typically to wedges.
Hard-Stepping: Assembly process of placing a shaft that has a shorter than normal tip section into a given club. For example, placing a 4-iron shaft into 3-iron head is hard stepping which will result into a firmer shaft.
Heel-Toe Weighting: A type of club head design in which weight is positioned toward the heel and toe of the clubhead in an attempt to stabilize the clubhead (and produce straighter shots) on off-center impacts.
High-Modulus Graphite: A shaft material stiffer than standard graphite. The higher the modulus of graphite, the lower its compression strength will be.
High Polish Finish: Shiny (mirror) finish applied to stainless steel iron heads through a series of polishing belt operations.
High Spin Ball: Any one of a number of golf balls designed for maximum spin and control. High spin balls are generally soft feeling and are preferred by better players.
Hook Face: A wood that has a face angle that is closed. Hook face woods may help players who slice the ball to be able to hit the ball straighter.
Horizontal Flow Weighting: A manner of distributing weight from club to club in a set of irons in which the highest concentration of weight moves from the toe of the longer irons to the heel of the shorter irons or vise versa.
Hosel: The entry point of the shaft into the head on any golf club.
Hybrid: Generic term given to any club designed from characteristics of a wood and an iron. The TaylorMade Rescue clubs popularized this type of club also known as an “Iron/Wood.”
Injection Molding: A method of manufacture (typically involving wood heads and face inserts) in which the material (ABS, epoxy, graphite, etc.) comprising the head is heated to a liquid state and injected under pressure into a mold. When the material hardens, it takes the shape of the mold into which it was injected.
Inset Hosel: A club design that moves the position of the hosel toward the center of the club face in an attempt to reduce head twisting. The United States Golf Association (USGA) Rule lists a maximum inset of 0.625″ or 16 millimeters above the horizontal plane on which t
he club is resting in its normal address position.
Ironwood: See Hybrid.
Keel Sole: The sole of a wooden or metal wood that is “V” shaped and designed to lower the club’s center of gravity to assist in getting the ball airborne from a less than perfect lie.
Kick Point: The point of maximum bending of a shaft as measured by deflecting the tip end while the butt remains stationary.
Knurling: The decorative cosmetic engraving found on the hosel of an iron or putter head. Knurling commonly consists of a series of lines or “X’s” near the top of the hosel. It is more often found on clubs from the 1960’s and prior.
Laminated Wood: A wood head manufactured by gluing together and compressing several thin pieces of maple, which is then forming them into the shape of a golf club head.
Launch Angle: The angle of a ball’s flight immediately after it leaves the club face.
Launch Monitor: Specialized fitting device that measures the launch angle, ball speed and spin rate after impact. Results from Launch Monitor testing seek to determine the optimal loft for a player’s club.
Lead Powder: Once a common swingweighting material used in either a wood’s weight port or in a steel shaft tip to achieve a given club weight.
Lead Tip Pin (Tip Weight): A short piece of lead that is epoxied into a shaft from the tip end prior to shaft installation for the purpose of achieving a specific club weight.
Leading Edge: The forward most point of the club face.
Lie: The angle between the shaft and the ground line when the club is measured in normal playing position.
Lift: Upward force on a golf ball as it flies.
Lightweight Shaft: A weight classification of shaft that falls within 100 and 120g in steel shafts and within 70 and 90g related to composite shafts.
Loading (Shaft loading): The energy buildup or deflection in a shaft as it is swung.
Loft: The angle created as measured from the center of the club face in relationship to the hosel bore with the head in the squared position. More simply, it is the angle of the club face as related to the shaft position.
Lorythmic Swingweight Scale: A type of scale that measures swingweight at a point 14″ down from the butt end of the club and displays those measurements in letter/number designations (D-1, D-2, etc.)
Lost Wax Investment Casting: The investment casting process used to produce irons, putters, and metal woods that initially involve making a master model of the club head. A mold is then made from this master. Wax is injected into these molds, forming a duplicate of the club head. A ceramic material is then used to coat the waxes. The ceramic is heated after hardening, causing the wax to be removed. Metal is then poured into the now empty ceramic pieces to form the actual investment cast club head.
Low Balance Point: A shaft that has a high percentage of its weight toward the tip. Such shafts are designed to assist in positioning more mass toward or behind the hitting area of the club. These types of shafts will tend to create clubs with higher than normal swingweights.
Low Profile Head: An iron or wood head that is shorter from its topline to sole line than typical.
Low Spin Ball: Any of a variety of balls designed for less spin. Reduced spin generally yields more distance.
M1 Bore: The bore type in a metal wood in which there is a distance of 1 1/2″ from the ground line to the point at which the shaft bottoms out in the hosel. This may also be referred to as “standard bore” or “metal wood bore.” Most common bore type for todays large, titanium drivers.
M2 Bore: Type of metal wood bore in which the shaft bottoms out in the hosel 1″ from the ground line. Most common bore type found in today’s fairway woods.
Mallet: A type of putter head identified by its broad appearance from front to back when positioned at address.
Mandrel: A tapered steel rod around which composite materials are wrapped when making a composite shaft.
Maraging Steel: An alloy or family of steels with unique properties. Typically maraging steels are harder than are non-maraging steels such as 17-4 and 15-5. Maraging steel is commonly used in club face applications, rather than in entire club heads.
Master: The exact replica (typically made from brass or aluminum) of a wood, iron or putter head from which all heads will be duplicated.
Medallion: Any number of decorative inlays made of metal, Mylar and urethane type units which are affixed commonly in the cavities of woods or putters, but may also appear on metal woods. The units are designed for cosmetic purposes, enhancing the attractiveness of the club heads.
Melonite: A quenching process applied to heads
that is designed to prevent corrosion. The process gives the heads
a black appearance.
Milled Face: A club face, usually on a putter, that has, on a specialized machine, its face milled to .001″ for flatness. The concept that a flatter face will promote smother roll is embraced by a majority of golfers.
Mirror Finish: See High Polish Finish.
Modulus: The measure of a fiber’s stiffness or resistance to bending. The higher the modulus, the stiffer the material will be.
Moment of Inertia (MOI): The resistance to twisting of any golf club head when that head is impacted by an off-center shot.
Multi-Layer Ball: Design of a ball in which a large core comprises most of the ball. The core is then surrounded by one or two outer layers of material, with one of those being the cover.
Muscleback Iron: See Blade Style Iron.
Non-Conforming Ball: Any ball that does not meet the requirements as set forth in Appendix III of the USGA Rules of Golf.
Non-Conforming Club: Any ball that does not meet the requirements as set forth in Appendix II of the USGA Rules of Golf.
OEM (Original Equipment Manufacturer): A golf club company that, as its main concern, sells completed clubs either on the wholesale level or to the general public.
Official Swingweight Scale: A type of swingweight scale that uses a 12″ fulcrum as its measuring point, providing balance in ounces and total weight in ounces or grams. Not typically used in many shops.
Offset: The distance from the forward most point of the hosel to the leading edge of the face.
Onset (Negative Offset): The design of a head in which the leading edge of the blade or face is forward of the leading edge of the hosel.
Overall Distance Standard: USGA parameter for conforming balls that limits their overall carry and roll to 280 yards or less (+/-6%).
Overall Weight: See Total Weight.
Over-Hosel: Type of shaft-to-head assembly in which the shaft fits over a post protruding from the head. Not nearly as common as in-hosel assemblies, over-hosel applications are used on irons and putters only.
Oversize Iron Head: The generic name given to any number of iron heads larger than standard. An oversize iron has a blade height of approximately 47+ millimeters and a blade length of 85+ mm.
Oversize Shaft Tip: An iron shaft with a tip larger than .370″ or a wood with a tip larger than .350″. Certain manufacturers claim that larger tip diameter shafts will assist in the stabilization of club heads, especially on off-center impacts.
Parallel Tip Shaft: The type of shaft construction in which the shaft has one constant diameter in its tip section. .370″ is a common tip size for parallel tip iron shafts, while .335″ is common for wood shafts. Parallel tip shafts can often be used in any club in a set; the same shaft can be used to assemble a #1 iron all the way through to the SW. Parallel tip shafts are favored by clubmakers, although a number of OEM’s use them as well.
Perimeter Weighting: The design concept of redistributing the weight on the head to the heel and toe in an attempt to stabilize the club on all types of impacts.
Persimmon: A material with which to manufacture wooden woods. Woods made from persimmon are made from one solid block of wood. Persimmon woods, while once very popular in the 1960’s, have lost favor to metal woods. Persimmon woods are considered to be the “best” type of wooden woods produced and demand a premium price as a result. Persimmon is still being manufactured today, most notably by Louisville Golf in Louisville, Kentucky.
Progressive Offset: Iron head design feature in which longer irons have more offset and shorter irons have less. The offset progresses in somewhat uniform increments through the set. More offset is featured in long irons as offset tends to eliminate pushed or sliced shots and helps most players hit the ball straighter.
Proprietary: Any feature of a golf club that is unique to a particular manufacturer. For example, each manufacturer’s head or shaft designs are proprietary to that manufacturer. Proprietary designs, logos, etc. are often patented by the company developing them in order to secure their exclusive use for a given time period.
Prorythmic Swingweight Scale: A type of swingweight scale that bases its measurements on a 14″ fulcrum system, additionally providing weights in ounces or grams.
Punch Dot: A series of circular indentations or dots on the face of an iron head in place of lines. Dot Punch patterns may be arranged much like lines or may be in a more circular pattern. They are most common on wedges.
Rails: Found on the soles of metal woods, rails function to lower the center of gravity of the club and to provide less resistance as the club travels through the turf.
Ribbed Grip: A grip that has a noticeable ridge along its back or underside to help assist place the hands into the proper position. This type of grip may also be known as a reminder grip.
Rocker Sole: See Camber Sole.
Rockwell Hardness: One possible scale used to determine the hardness of golf iron heads. Typically 1030 stainless steel has a Rockwell Hardness of B80, 18-8 steel rates B90, 431 tests at C18, while 17-4 has a hardness of C35 and maraging steel is hardest at C45.
Roll: The measure of face curvature from crown to sole on wood and hybrid clubs.
Round Grip: A grip that tapers uniformly the entire distance along its length and has no discernible ribs.
Sandblast: The finish applied to the faces of many iron heads. It is slightly rough in texture. It is also the term given to the gray color applied to certain metal wood heads.
Satin Finish: Type of finish applied to any metallic surface through a series of finishing belts and appears as a brushed aluminum type of finish.
Scoop (Dig) Sole: An iron whose leading edge is lower than its trailing edge is determined to have a scoop sole. This type of design would be considered to have a negative bounce angle.
Scoring lines: Any markings on a club face, primarily for decorative or alignment purposes. Examples include, but are not limited to, lines, dots, circles and/or triangles.
Sensicore?: A vibration dampening core, developed by True Temper, and inserted into the shaft to reduce vibration.
Shaft Extension: A piece of material that is inserted into the butt end of a shaft for the purpose of making a club longer. The extension, with a maximum of no more than 2″, may be made of wood, steel, aluminum, hard plastic or graphite.
Shaft Pattern: The design of a particular shaft indicated the distribution of steps along the length of the shaft. Pattern is also the term used to designate a particular model of shaft, e.g., Dynamic, TT Lite, and Shadow, etc.
Shallow Face: Any wood or iron having a face height less than the norm. Shallow face clubs typically have lower center of gravity, thus making them easier to get airborne.
Sheet Wrapping: The process of making a graphite shaft in which sheets of graphite and epoxy resin are wrapped around a mandrel to produce a shaft. It may also be known as “Table Rolling.”
Shot Peen Finish: Type of finish applied to stainless steel iron heads
that leaves the appearance of a “silvery, semi-rough” surface.
Silkscreen: A method of identification found on most shafts. On steel shafts, it typically encircles the shaft at the first step or approximately 1/4″ of the shaft length from the tip end. Related to graphite shafts, it is much more colorful and noticeable and is found toward the middle of the shaft.
Soft-Stepping: A process of assembly in which a shaft with a longer tip section is put into a club that would normally require a shorter tip section in order that the club play to a softer flex. Installing a #2 iron shaft into a #3 iron to gain more flexibility is an example of this process.
Sole: The underside portion of any type of golf club. It is the area where the club rests on the ground in playing position.
Sole Width: The measure of a club’s sole from its leading edge to its trailing edge.
Sole Weighted Iron: The design of an iron had in which the majority of its weight is concentrated toward the sole of the club. This produces a lower center of gravity making it easier to get the ball airborne.
Solid Ball: Also known as a two-piece ball, a solid ball is characterized as one with a cover (usually of a durable material) molded over a central core.
Spin Rate: The amount of spin on a golf ball as measured in revolutions per minute (rpm).
Spring-Like Effect: A general term given to the faces of metal woods elated to how much the face compresses and decompresses (springs back) upon ball impact. The USGA established standards for this effect, based upon their assumption that if a face springs more, overall ball distance may be increased. Also known as the “Trampoline Effect.”
Square (Box, “U”) Grooves: Face lines (or grooves) pressed, cut or cast in a rectangular shape during manufacture.
Standard Weight Shaft: A steel shaft weight classification that weighs above 120g.
Static Fitting: The process of fitting an individual without actually watching him or her hit balls. Examples of static fitting include mailed in fitting forms, and telephone fitting.
Static Weight: Also known as overall weight or total weight, static weight is the weight of the entire assembled club as expressed in ounces or grams.
Step: Location on a steel shaft where the diameter of the shaft changes or “steps up” to a larger diameter. The average steel shaft has numerous steps which help identify its playing characteristics and/or manufacturer.
Stepless: A shaft that does not have any steps. Nearly all graphite shafts are stepless. The most popular stepless steel shaft today is the Rifle.
Strong Lofted: The loft of any club, particularly an iron that is less than the standard specification for that club. Stronger lofted clubs tend to hit the ball lower and longer than standard lofts, but may sacrifice some control.
Surlyn: A thermoplastic resin (ionomer), invented
by DuPont in the late 1970’s, Surlyn is a very common material in
durable golf ball covers.
Sweet Spot: The position on the club’s face at which maximum energy and feel will be transferred.
Swing Computer: Device used in club fitting to accurately define swing characteristics such as swing path, speed, tempo, face angle, etc. Typically used indoors only, swing computers will cost several thousands of dollars and will graphically display a golfer’s swing, aiding in the fitting process.
Swingweight: A club’s weight distribution around a fixed fulcrum point. The fulcrum point is typically 14″ from the butt of the club. Swingweight is commonly referred to as the relationship between the weight of the grip end of the club and head end. It is measured in alpha-numeric units such as D-1, D-2, and so on with higher letter-number units indicating more weight in the head relative to the grip.
Swingweight Scale: A measuring scale specific to golf clubs that utilizes a balance system to determine the swingweight and possibly the total weight of a golf club.
Taper Tip Shaft: A shaft whose tip immediately increases in diameter as opposed to maintaining the same dimension for and extended length. One of a number of shafts manufactured with a tip section that varies in length and thickness below the first step. This type of shaft (in steel) requires that a specific length, known as a discrete length, shaft be made for each club in a set. Taper tip shafts are only used by select OEM’s.
Tensile Strength: Resistance of a material (i.e., epoxy) to being stretched or elongated.
Thermoplastic Hosel: Type of hosel found on Ping TISI drivers allowing the company to produce these clubs with a variety of face angle and lie angle options.
Thermoset: A material that once heated and cured cannot be re-shaped or re-formed.
Three-Piece (Ball): Generic term given to a ball with a center core, rubber windings and a cover. A three-piece ball may also have a center and two “cover” materials, eliminating the windings.
Ti-Alloy: A metallic alloy used for wood heads that contains some titanium. Typically Ti-alloy heads are comprised mostly of aluminum and are considered to be of lesser quality than other head materials.
Tipping (or Tip Trimming): The process of trimming a shaft from the tip to increase its stiffness.
Tip Stiff: Design of shafts (typically graphite shafts) which feature a firmer tip section as compared to the remaining portion of the shaft.
Titanium: Club head material utilized primarily for woods and irons, it has a higher strength-to-weight ratio than most steel alloys. See also Beta-Titanium, Forged Titanium and 6-4 Titanium. Titanium can also used in shaft production.
Topline: The uppermost part of an iron blade, running from heel to toe. It is the part of the iron head that a player typically looks down upon when addressing the ball.
Torque: The amount of twist in a shaft under a given amount of force. Lower torque shafts twist less than do higher torque shafts.
Total Weight: Also known as overall weight or static weight, total weight is the weight of the entire assembled club as expressed in ounces or grams.
Tour Weight: The somewhat generic term applied to composite shafts that weigh approximately the same as standard weight steel shafts (@125 grams.) or at least greater than 90g.
Trajectory: The shape and height of a shot in relation to its direction.
Trailing Edge: The most rearward part of a club’s sole.
Trampoline Effect: See Spring-Like Effect.
Tumble Finish: Type of finish applied to iron and metal wood heads via a specialized tumbling machine containing various tumbling media. Finish is characterized by its dull, durable look.
Tungsten: A high-density metallic compound used to add weight to a club head, either as a swingweighting material in the shaft or as a defined weight attached somewhere in/on the head.
Two-Piece (Ball): Type of ball characterized by a center core surrounded by a cover, usually made of a durable material.
Two-Way Tape: Also known as “Double-Sided” or “Grip” tape, a type of tape, with adhesive on both sides that is used along with a solvent to secure grips in place.
Ultra-lightweight Shaft: A weight classification of shaft that falls below 100g in steel shafts and below 70g related to composite shafts.
Undercut Cavity: A design feature in irons, where a “channel” is formed between the face and rear of the club in order to displace more weight rearward in the clubhead for greater stability and a high launch angle.
Underlisting: The rubber or paper material onto which a leather or two-piece synthetic grip is wrapped.
Unitized: An entire set of irons or a full set of woods can be built through successive trimming of the shaft tip section of a single shaft.
Unloading (Shaft Unloading): The energy release as a shaft is swung or as the shaft straightens out from its deflected state.
Upright Lie: A club’s lie that is more upright than the standard specification for that particular head. For example, a 62 degree head would be 2 degrees upright if the stated specification was originally 60 degrees.
“V” Grooves: Face lines (or grooves) pressed, cut or cast into a triangular (or “V”) shape during club manufacture.
Vertical Flow Weighting: The method of flow weighting in which the weight moves vertically from a concentration of weight toward the sole of long irons to more traditional weighting on short irons.
Volume: A numerical designation given to the size of a club head (normally a wood or hybrid) as measured by liquid displacement.
Weight-Sorted: Club components that are weighed prior to assembly in an attempt to ensure consistent specification of the finished golf club.
Whipping: The black, thread-like covering applied around the neck of a “wooden” wood to prevent the neck from splitting during play.
Wound Ball: Type of ball characterized by a cover over a matrix of rubber windings that cover a central core. Wound balls often have a softer feel and higher spin rate than other ball types. They may also be called three-piece balls.
X-Out: General term given to less than perfect balls. Usually top grade balls with a slight cosmetic or manufacturing defect, X-outs are identified by a row of “X’s” somewhere on the cover. X-outs are substantially less costly than first-quality balls.
Zinc Iron Heads: Iron heads die cast from an alloy of zinc. These heads typically are considered less expensive and less durable than their stainless counterparts and thus are designated primarily for beginner sets. Zinc heads can be identified by their non-magnetic properties as well as by their typically larger diameter than normal hosels.