SCM440,4140,4142,708M40,709M40,42CrMo4 Material comparison table

* SCM440,4140,4142,708M40,709M40,42CrMo4 Material comparison table

(Chromium molybdenum steels)

 

1. Chemical composition

Code	KS	JIS	AISI	AISI	BS	BS	DIN
Material Grade	SCM440	SCM440	4140	4142	708M40	709M40	42CrMo4
C	0.38~0.43	0.38~0.43	0.38~0.43	0.40~0.45	0.36~0.44	0.36~0.44	0.38~0.45
Si	0.15~0.35	0.15~0.35	0.15~0.30	0.15~0.30	0.10~0.35	0.10~0.35	0.15~0.40
Mn	0.60~0.85	0.60~0.85	0.75~1.00	0.75~1.00	0.70~1.00	0.70~1.00	0.50~0.80
P	≦0.030	≦0.030	≦0.035	≦0.035	-	-	≦0.035
S	≦0.030	≦0.030	≦0.040	≦0.040	-	-	≦0.035
Ni	<0.25	<0.25	-	-	-	-	-
Cr	0.90~1.20	0.90~1.20	0.80~1.10	0.80~1.10	0.90~1.20	0.90~1.20	0.90~1.20
Mo	0.15~0.30	0.15~0.30	0.15~0.25	0.15~0.25	0.15~0.25	0.25~0.35	0.15~0.30
Cu	<0.30	<0.30	-	-	-	-	-
Remark	-	-	In AISI 3 C0.36~0.44 Mn0.70~1.00 Cr0.80~1.15	In AISI 3 C0.38~0.46 Mn0.70~1.00 Cr0.80~1.15	-	-	-

(Referred to KS, JIS, AISI, BS, DIN)

 

2. Mechanical property (SCM440)

Heat Treatment	yield point kgf/mm^2 (N/mm^2)	tensile strength kgf/mm^2 (N/mm^2)	elongation %	contraction of area %	hardness (HB)	charpy impact value kgf.m/cm^2 (J/cm^2)
Quenching 830~880℃ Oil cooling Tempering 530~650℃ Quick cooling	85≦ (834)≦	100≦ (980.7)≦	12≦	45≦	285~352	6≦ (59)≦

(Referred to KS, JIS)