Strength & Hardness of Spring Materials

The following table shows, as a first approximation and under reserve, the equivalence between hardness in Vickers (HV), Rockwell C (HRC) and mechanical strength, Rm (N/mm2) for the various metallic materials (steel and stainless steel).

RM (N/mm²)	HV	HRC	RM (N/mm²)	HV	HRC	RM (N/mm²)	HV	HRC
300	89.7	-	1100	337.2	34.2	1900	584.6	54.4
325	97.4	-	1125	344.9	35.0	1925	592.4	54.8
350	105.2	-	1150	352.6	35.8	1950	600.1	55.2
375	112.9	-	1175	360.4	36.6	1975	607.8	55.6
400	120.6	-	1200	368.1	37.5	2000	615.6	56.1
425	128.4	-	1225	375.8	38.2	2025	623.3	56.6
450	136.1	-	1250	383.6	39.1	2050	631.0	57.2
475	143.8	-	1275	391.3	40.0	2075	638.8	57.3
500	151.6	-	1300	399.0	40.8	2100	646.5	57.6
525	159.3	-	1325	406.8	41.3	2125	654.2	57.8
550	167.0	-	1350	414.5	42.2	2150	662.0	58.1
575	174.8	-	1375	422.2	42.9	2175	669.7	58.5
600	182.5	-	1400	430.0	43.6	2200	677.4	58.9
625	190.2	-	1425	437.7	44.2	2225	685.2	59.3
650	198.0	-	1450	445.4	44.9	2250	692.9	59.7
675	205.7	-	1475	453.2	45.6	2275	700.6	60.1
700	213.4	-	1500	460.9	46.2	2300	708.4	60.4
725	221.2	-	1525	468.6	46.8	2325	716.1	60.7
750	228.9	-	1550	476.4	47.3	2350	723.8	61.0
775	236.6	-	1575	484.1	48.0	2375	731.6	61.3
800	244.4	21.3	1600	491.8	48.7	2400	739.3	61.7
825	252.1	23.0	1625	499.6	49.1	2425	747.0	62.0
850	259.8	24.0	1650	507.3	49.3	2450	754.8	62.3
875	267.6	24.9	1675	515.0	50.0	2475	762.5	62.6
900	275.3	26.4	1700	522.8	50.8	2500	770.2	62.8
925	283.0	27.6	1725	530.5	51.2	2525	778.0	63.0
950	290.8	28.6	1750	538.2	51.6	2550	785.7	63.3
975	298.5	29.5	1775	546.0	52.2	2575	793.4	63.6
1000	306.2	30.6	1800	553.7	52.8	2600	801.2	64.0
1025	314.0	31.6	1825	561.4	53.2	2625	808.9	64.3
1050	321.7	32.3	1850	569.2	53.7	2650	816.6	64.6
1075	329.4	33.2	1875	576.9	54.1	2675	824.4	64.9

Source: https://www.matthey.ch/aide-technique/equivalence-durete-/-resistance