Table A-20 Deterministic ASTM Minimum Tensile and Yield Strengths for Some Hot-Rolled (HR) and Cold-Drawn (CD) Steels [The strengths listed are estimated ASTM minimum values in the size range 18 to 32 mm (2 to 1 in). These strengths are suitable for use with the design factor defined in Sec. 1-10, provided the materials conform to ASTM A6 or A568 requirements or are required in the purchase specifications. Remember that a numbering system is not a specification.] 2 3 6 7 Process- ing UNS No. G10060 G10100 G10150 G10180 G10200 G10300 G10350 G10400 G10450 G10500 G10600 G10800 G10950 SAE and/or AISI No. 1006 1010 1015 1018 1020 1030 1035 1040 1045 1050 HR CD HR CD HR CD HR CD HR CD HR CD HR CD HR CD HR CD HR CD HR HR HR 1060 1080 1095 Source: Data from 1986 SAE Handbook, P. 2.15. Tensile Strength, MPa (kpsi) 300 (43) 330 (48) 320 (47) 370 (53) 340 (50) 390 (56) 400 (58) 440 (64) 380 (55) 470 (68) 470 (68) 520 (76) 500 (72) 550 (80) 520 (76) 590 (85) 570 (82) 630 (91) 620 (90) 690 (100) 680 (98) 770 (112) 830 (120) 5 Yield Strength, MPa (kpsi) 170 (24) 280 (41) 180 (26) 300 (44) 190 (27.5) 320 (47) 220 (32) 370 (54) 210 (30) 390 (57) 260 (37.5) 440 (64) 270 (39.5) 460 (67) 290 (42) 490 (71) 310 (45) 530 (77) 340 (49.5) 580 (84) 370 (54) 420 (61.5) 460 (66) Elongation in 2 in, % 30 20 28 20 28 18 25 15 25 15 20 12 18 12 18 12 16 12 15 10 12 10 10 Reduction in Area, % 55 45 50 40 50 40 50 40 50 40 42 35 40 35 40 35 40 35 35 30 30 25 25 8 Brinell Hardness 86 95 95 105 101 111 116 126 111 131 137 149 143 163 149 170 163 179 179 197 201 229 248 Problem 3-80 (Fatigue failure) A rotating countershaft carrying two V-belt pulleys is shown in the figure. Pulley A receives power from a motor through a belt with the belt tensions shown. The power is transmitted through the shaft and delivered to the belt on pulley B. Assume the belt tension on the loose side at B is 15 percent of the tension on the tight side. The countershaft is machined from AISI 1050 cold-drawn steel and has grounded surface, working temperature of 100 °C, all shoulder fillets of D/d = 1.2 and r/d = 0.1, and 90% reliability. Determine (a) the fatigue factor of safety based on achieving infinite life according to the Goodman line, (b) the yielding factor of safety. O 040 230 y 250-mm dia. B 230 mm T₂ 48 mm dia. 100 400-mm dia. 280 mm 1800 N Problem 3-80* 048 580 All dimensions in millimeter 300 mm 270 N A