CT has shot to prominence of late with many drivers on Tour being non conforming. We explain what it means here.

What Does CT Mean In Golf?

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’.

What does that term mean?

The term is what the USGA and R&A use to measure drivers and their ‘spring like’ effect off the face. In the past they had used COR (coefficient of restitution) to measure drivers but from 2004 they have used CT. ‘Spring like’ effect is exactly what it says on the tin; the springiness of the club-face. The springier the club-face is, the further the ball goes which explains why the governing bodies look to limit CT.

How do they measure for CT?

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.

The CT limit is 239 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.

Perfectly legal drivers can become non-conforming over time through normal use as the club “creeps” beyond the allowed limits.

The term and measurement has become a hot topic in the world of golf as several players drivers in 2019 were ruled to be non-conforming. For example Xander Schauffele‘s driver was tested at The Open and then at the Safeway Open five players had drivers tested that were judged to be over the limit.

CT is a measurement only used for drivers whereas COR is still used to measure fairway woods, hybrids and irons.

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