What Does CT Mean In Golf?

What Does CT Mean In Golf?

With the golf ball roll back the latest discussion in order to reduce professional golfers over-powering courses and potentially bringing some older courses back onto the tour, should we not be looking more into clubhead design? With distance becoming a bigger and bigger topic in the world of professional golf, an acronym that has risen alongside that is CT, which means 'characteristic time'. 

The term is what the USGA and R&A use to measure driver faces and just how 'springy' they are. You may remember a few years back in 2019, Xander Schauffele was subject of a random driver test on the range prior to The Open Championship and was actaully told his driver was non-conforming to the rules. COR (Coefficient of restitution) was used in the past but CT was introduced from 2004. However, CT is a measurement only used for drivers whereas COR is still used to measure fairway woods, hybrids and irons.

A big sell for major manufactures is how far they are promising each of their drivers will send the golf ball and the face design has a huge role to play in that. The more 'springy' the face, the more it can flex and send the ball forward at a greater force. The CT limit is 239 microseconds with a tolerance of 18 microseconds allowed, making the absolute maximum limit a reading of 257 microseconds. Club manufacturers usually look to get as close to 257 as possible without going over the limit.

So how exactly do the governing bodies measure CT? Well, a pendulum-type device measures how long a metal golf ball-shaped bob is in contact with the the club-face when swung at it from various heights, with the measurement in micro-seconds. The metal bob has very precise sensors inside it that give the time.

Perfectly legal drivers can become non-conforming over time through normal use as the club “creeps” beyond the allowed limits. Many major manufactures will now actually travel with a CT testing machine on their tour trucks to test all their contracted players drivers when building one up for the week. If you have ever seen a close up of a tour players driver and there is a white dot on the middle of the face, this will be a sign that the driver has been CT tested.