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14 confusing equipment terms, explained

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I’ve often referred to our meetings with equipment company’s R&D teams as like going to a physics class. It can also, at times, be akin to a foreign language class. The terminology of golf equipment can be as daunting as a long iron over water. For the gearhead looking to expand their knowledge base or those simply seeking to be more knowledgeable on the topic of golf equipment, we’ve compiled 14 of the more common—and often confusing—equipment terms and tried to explain them in their simplest, easiest-to-understand way. We won’t have a final exam but if you read below closely you’ll be speaking fluent equipment-talk in no time.


The degree to which the sole of a club angles up and away from the ground plane when the club is in a square setup position. In general, more bounce is better for soft sand and high, lush grass; less bounce is better for firm sand and turf.


The face curvature from heel to toe that corrects spin on mis-hits.


The radius measurement of the sole from front to back or heel to toe.


A way of manufacturing a clubhead by pouring molten metal into a mold.

Center of Gravity (CG)

A theoretical point that defines the average location of weight in a clubhead and the internal point about which an object rotates. A low CG helps to launch the ball higher. A club's CG isn't always found at its geometric center.

CNC Milling

Computer Numeric Controlled (CNC) milling is a process by which an automated machine cuts and shapes solid blocks of metal by reading code. Grooves and faces are often made in this manner to ensure tight tolerances.

CT (Characteristic Time)

The USGA developed this to measure for spring-like effect by using a measurement of characteristic time (CT). The allowable limit is 239 microseconds—this is the amount of time the clubface remains in contact with a small steel ball swung from a pendulum apparatus at the moment of impact. A tolerance of 18 microseconds is also added, so although the limit is 239, any driver measuring 257 microseconds or less passes the test. The test is not limited to the center of the face, but several points on the face where impact might occur.

Face Balanced

When holding a putter face up when balanced at the shaft tip, a face-balanced putter should be perfectly level. This style of putter is generally thought to work well with strokes that are relatively straight back and straight through.

Facecup or Cupface

A type of clubhead construction where part of a club’s face wraps around the part of the crown and sole, allowing for more rebound at impact. Once only found in metalwoods, it is now a staple of some irons as well, many of which use an L-face, where the face only wraps around the sole, not the topline, as most iron impacts are low on the face.


A method of manufacturing a clubhead by heating metal then stamping it into shape.

Moment of Inertia

Although often thought of solely as the measure of a club's resistance to twisting on off-center hits, moment of inertia really is a method to mitigate ball speed loss on mis-hits. The USGA limit for drivers is 5,900 grams/centimeters squared.

Polymer or TPU

A synthetic material that is lightweight, resilient and can be engineered to meet a range of hardnesses. The material is often used inside iron clubheads to enhance feel.


Often referring to wedges where an area of material on the sole has been removed to increase versatility and reduce turf drag.

Toe Hang

The angle the toe of the putter deviates from horizontal when balanced at the shaft tip. In general, the more the angle, the better suited it is for arced putting strokes.

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