Sine Bar Both Sine Bar and Rolls are hardened and ground for extreme accuracy. Top surface is accurate to 0.00003" per length. Various size holes are furnished for clamping purposes. Parallelism to 0.00004". Sine bars and sine plate to have tapped holes for hold downs. Center to Center distance between center of rolls is accurate within 0.0002". Flange on the end is for resting work. Features include... 5" Length between center of rolls 15/16" Wide Hardened and ground steel