4340 DIN 1.6580 30CrNiMo8 SNCM431 Hardened Steel Round Bar

Name: 4340 DIN 1.6580 30CrNiMo8 SNCM431 Hardened Steel Round Bar
Brand: fushun
SKU: 18192847
Rating: 4.75 (10 reviews)

Categories	Hardened Steel Bar
Brand	fushun
Model	4340， DIN1.6580， 30CrNiMo8，SNCM431
Diameter	50-260mm
Delivery condition	harden
Surface condition	black, bright
FOB port	shanghai
Terms of Payment	L/C, T/T
Update Time	May 10,2025

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Detail Information

Applications

Alloyed heat treatable steel with a typical tensile strength of 1100 -1300 N/mm². Used for highly stressed components, where the combination of high strength with tenaciousness is of utmost importance. High cold formability: Parts of different shape can be manufactured, a favorablefibering for stress, a very good surface condition and an high dimensional accuracy. When cold formed the smooth surface leads to an increased fatigue and vibratory strength.

Chemical Composition(%)

Steel Grade	C	Mn	Si	P	S	Cr	Ni	Mo
30CrNiMo8	0.26-0.34	0.50-0.80	0.40 max	0.025 max	0.035 max	1.80-2.20	1.80-2.20	0.30-0.50
4340	0.38–0.43	0.60-0.80	0.15-0.35	0.035 max	0.040 max	0.70-0.90	1.65-2.00	0.20-0.30
SNCM431	0.27-0.35	0.60-0.90	0.15-0.35	0.030 max	0.030 max	0.60-1.10	1.60-2.00	0.15-0.30

All Grades Comparison

Material no.	DIN	BS	ASTM
1.658	30CrNiMo8	823M30	4340
AFNOR	ISO	ГOCT	JIS
30CND8	31CrNiMo8	3KH3M3F	SNCM431

Mechanical Properties(T=20°C if not differently stated)

Heat treatment state	Diameter(mm)	Rm (Mpa)	Rp0.2 (Mpa)	Fracture elongation A5 (%)	Notch impact energy ISO-V [J]	Hardness (HB)
SOFT ANNEALED	/	844 min	/	/	/	250 max
ISOTHERMAL ANNEALED	/	615-815	/	/	/	183-242
QUENCHED AND TEMPERED	16 max	880-1080	685 min	16 min	40 min	289-347
QUENCHED AND TEMPERED	16-40	930-1080	735 min	16 min	40 min	275-318
QUENCHED AND TEMPERED	40-100	880-1030	685 min	17 min	40 min	261-303
QUENCHED AND TEMPERED	100-250	785-935	635 min	18 min	35 min	233-276
QUENCHED AND TEMPERED	250-500	735-885	590 min	16 min	35 min	218-262