ST - STRAIGHT SHANK SHRINK A ➚ A .00012 58-60 HRc Ra 4µin G2.5 L max 20,000 RPM L min 4° D1h6 d1 d D L1 L Designation d D D1 d1 L L1 Lmin Lmax ST 1/2X6.30 SRK 1/8 .125 .394 .500 .157 6.300 .760 .394 - ST 1/2X6.30 SRK 3/16 .188 .394 .500 .157 6.300 .760 .591 1.181 ST 5/8X6.30 SRK 1/8 .125 .394 .625 .236 6.300 1.374 .394 - ST 5/8X6.30 SRK 3/16 .188 .394 .625 .236 6.300 1.654 .591 - ST 5/8X6.30 SRK 1/4 .250 .433 .625 .236 6.300 1.374 .709 1.378 ST 3/4X8.00 SRK 3/16 .188 .394 .750 .236 8.000 2.548 .591 - ST 3/4X8.00 SRK 1/4 .250 .433 .750 .236 8.000 2.267 .709 1.378 ST 3/4X8.00 SRK 5/16 .313 .551 .750 .236 8.000 1.422 .984 1.575 ST 1X8.000 SRK 1/4 .250 .433 1.000 .315 8.000 4.053 .709 1.378 ST 1X8.000 SRK 5/16 .313 .551 1.000 .315 8.000 3.209 .984 1.575 ST 1X8.000 SRK 3/8 .375 .630 1.000 .315 8.000 2.646 1.181 1.772 ST 1X8.000 SRK 1/2 .500 .787 1.000 .315 8.000 1.520 1.260 1.969 832