50 - GB /T 17107-1997

Grade	50
Corresponding Standard	GB /T 17107-1997 Structural Steel Grades And Mechanical Property For Forgings
Classification	Carbon Steel

50 Chemical Element Composition Content (%)

Component	C	Si	Mn	P	S	Cr	Ni	Cu
Minimum Value	0.47	0.17	0.5	-	-	-	-	-
Maximum Value	0.55	0.37	0.8	0.035	0.035	0.25	0.25	0.25

• High-quality steel——P≤0.035；S≤0.035；Cu≤0.3；Cr≤0.3；Ni≤0.3
• Extra-quality steel （Suffix A）——P≤0.025；S≤0.025；Cu≤0.25；Cr≤0.3；Ni≤0.3
• Special High-Quality Steel (Suffix E)——P≤0.025；S≤0.015；Cu≤0.25；Cr≤0.3；Ni≤0.3

• Cu is not more than 0.3% when smelting scrap steel

50 Mechanical Properties

diameter or thickness d mm	Mark	Heat Treatment or Condition	Tensile Strength σ_b Mpa	Yield Point σ_s Mpa	Elongation or Extension Rate δ %	Reduction of Area ψ %	Hardness HBW	Impact Energy Absorption KV2 J
d≤100	Sample Direction: Longitudinal	Normalizing + tempering	≥610	≥310	≥13	≥35	-	≥23
100＜d≤300	Sample Direction: Longitudinal	Normalizing + tempering	≥590	≥295	≥12	≥33	-	≥19
300＜d≤500	Sample Direction: Longitudinal	Normalizing + tempering	≥570	≥285	≥12	≥30	-	≥19
500＜d≤750	Sample Direction: Longitudinal	Normalizing + tempering	≥550	≥265	≥12	≥28	-	≥15
d≤16	Sample Direction: Longitudinal	Tempering	≥700	≥500	≥14	≥30	-	≥31
16＜d≤40	Sample Direction: Longitudinal	Tempering	≥650	≥430	≥16	≥35	-	≥31
40＜d≤100	Sample Direction: Longitudinal	Tempering	≥630	≥370	≥17	≥40	-	≥31
100＜d≤250	Sample Direction: Longitudinal	Tempering	≥590	≥345	≥17	≥35	-	≥31
250＜d≤500	Sample Direction: Longitudinal	Tempering	≥590	≥345	≥17	-	-	-

• The forgings must be inspected for mechanical properties after performance heat treatment and before any surface treatment.
• After the samples are removed, no heat treatments that affect the mechanical properties or any processing that influences the test results shall be conducted.
• Mechanical property testing primarily evaluates the material\'s tensile strength, impact resistance, and hardness. When conducting tensile, impact, and hardness tests simultaneously, the hardness value is for reference only. Alternatively, one may choose to perform only one of the tensile, impact, or hardness tests.

1 Approximate Comparison Table High-Quality Carbon Structural Steel

China

Taiwan, China

Japan

South Korea

United States

International Organization for Standardization

Germany

France

Russia

Sweden

United Kingdom

ISC

CNS

JIS

ASTM/AISI

UNS

ISO

DIN EN/DIN

W-Nr.

NF EN/NF

GOST

BS EN/BS

U20502

S50C

SM50C

1050

G10500

C50E4

C50E
Ck53

1.1210

C50E

1674

C50E
080M50

2 Approximate Comparison Table Carbon Structural Steel and Engineering Steel

China	Japan	International Organization for Standardization
GB	JIS	ISO
50	S50C	C50

3 Approximate Comparison Table Non-Alloy Steel for Quenching and Tempering

China	Japan	International Organization for Standardization	European Standard
GB	JIS	ISO	EN	Numerical Grade
50	S50C	C50E	C50E	1.1206

4 Approximate Comparison Table High-Quality Carbon Structural Steel

China	Japan	United States	International Organization for Standardization	Germany	France	European Standard		Russia	Sweden	United Kingdom
GB	JIS	ASTM	ISO	DIN EN/DIN	NF EN/NF	EN	Numerical Grade	GOST	SS	BS EN/BS
50	S50C	1049 1050	C50 C50E4	C50 Ck50	XC48H1	C50	1.0540	50	1674	070M50 080M50

5 Approximate Comparison Table High-Quality Carbon Structural Steel

China	Japan	United States	International Organization for Standardization	France	Russia	United Kingdom
GB	JIS	ASTM/AISI	ISO	NF EN/NF	GOST	BS EN/BS
GB/T 699-1999 50	S50C	1049 1050	ISO 630-1:1987 C50 C50E4 C50M2	C50 XC48	50	060A52

50 Corresponding Standards(Same grade name, different standards)

1	GB /T 699-1999
	50 U20502 (50#)
2	GB /T 699-2015
	50 U20502 (50#)
3	GOST 1050-1988
	50
4	GB /T 17107-1997
	50
5	GB /T 3078-2019
	50 50#
6	GB /T 710-2008
	50 U20502 (50#)
7	GB /T 711-2017
	50 50#
8	HB /Z 136-2000
	50
9	GB /T 13237-2013
	50
10	GB 3522-1983
	50

Note: The data is for reference only! If you have any questions, please fill out "I want to correct it"!