EXOTIN Roughing Cobalt High Speed Steel List 690: Regular Length - Multiple Flute - Center Hole Side Milling Hardness Up to 20 HRC 20 to 30 HRC 30 to 40 HRC 40 to 45 HRC Up to 50 HRC Work Material Mild Steels(up to 70x103 lb/in.2)Medium Tensile Steels(70x103 to 115x103 lb/in.2)Mild Steel ForgingsCast IronHigh Tensile Steels(115x103 to 142x103 lb/in.2) Heat Resistant FerriticLow AlloysHigh Tensile Steels(142x103 to 200x103 lb/in.2)Tool SteelsMedium StrengthStainless SteelHigh StrengthStainless Steels Cutting Speed 130-148 SFM 115-131 SFM 79-83 SFM 55-66 SFM 45-47 SFM Mill Dia. Speed Feed Speed Feed Speed Feed Speed Feed Speed FeedRPMin/minRPMin/minRPMin/minRPMin/minRPMin/min 1/4 2,230 6.0 1,770 4.5 1,250 3.0 940 2.3 700 1.5 5/16 1,700 7.9 1,600 6.3 1,000 3.5 800 2.8 560 1.5 3/8 1,470 10.3 1,180 7.0 835 4.0 660 3.3 470 1.9 1/2 1,100 9.3 900 6.4 630 4.1 425 3.1 355 1.9 5/8 850 12.5 715 8.4 500 6.3 400 4.0 280 2.4 3/4 725 14.8 590 8.4 420 6.0 325 4.3 235 2.4 7/8 630 14.0 500 8.4 350 6.0 280 4.5 200 2.4 1 560 14.0 450 7.9 310 6.0 250 4.5 175 2.3 1-1/8 490 12.1 400 7.0 270 6.0 220 4.3 160 2.4 1-1/4 450 11.8 355 7.0 250 5.5 200 4.0 140 2.3 1-1/2 370 10.1 300 6.6 210 4.5 165 3.3 115 1.9 1-3/4 315 8.8 250 6.0 180 4.0 140 2.8 100 1.5 2 275 7.8 220 5.0 155 3.5 120 2.3 90 1.4 1/2” Up to 1-1/8”; aa = 1.5 x D, ar = 0.5 x D 1-1/4” Up to 2”; aa = 1xD, ar = 0.5 x D WWW.OSGTOOL.COM End Mill Technical 1123