Pile refusal criteria shall be as per API RP 2A and repezted below for
clarity.
300 blows / 0.3m for 5 consecutive 0.3m (for contineous driving)
800 blows / 0.3m
800 blows / 0.152m (setup case)
The most stringent of the above shall be applied to determine the pile refusal.
Note:
Many times, the hammer manufacturer recommendation will be final.