Mechanical Properties & Hardness

Quench-and-tempering or heat treating requirements for 1045, 4140, and 4340 plate usually call out a hardness range, but it is not uncommon for an application to require certain mechanical properties beyond hardness. Normal ranges of mechanical properties corresponding to a specific hardness are listed below. These are intended as guidelines only; actual results may vary because of variations in chemistry, part configuration, and grain size, so please consult an Oliver sales engineer or your heat-treater. Also, it should be expected that 4340 will be at the high end of the range, and 1045 at the low end.

Hardness Rockwell C	Hardness Brinell	Tensile Strength (ksi)		Yield Point (ksi)		Elongation,%		Reduction Of Area, %
Hardness Rockwell C	Hardness Brinell	Low	High	Low	High	Low	High	Low	High
14	197	93	103	69	78	22	28	60	68
16	207	98	108	73	84	21.5	27.5	59	67
18	217	103	114	76	90	21	27.5	58	66
20	223	106	117	79	93	20.5	26.3	57.5	65.5
22	235	112	124	85	99	20	25.5	56.5	64.5
24	248	118	131	92	107	19.5	24.5	55	63
26	262	124	138	99	114	18.5	24	54	61.5
28	277	131	146	107	122	18	22.5	52	60
30	292	138	154	116	131	17	22	51	59
32	311	146	164	125	141	16	20.5	49	57
34	321	151	170	131	146	15.5	20	48	56
36	341	160	180	141	157	14.5	18.5	46	54
38	363	171	193	153	170	13.5	17	43.5	51.5
40	379	178	201	163	179	12.5	16	42	50
42	401	188	222	176	185	11	15	40	49