40 - GB /T 17107-1997

Grade	40
Corresponding Standard	GB /T 17107-1997 Structural Steel Grades And Mechanical Property For Forgings
Classification	Carbon Steel

40 Chemical Element Composition Content (%)

Component	C	Si	Mn	P	S	Cr	Ni	Cu
Minimum Value	0.37	0.17	0.5	-	-	-	-	-
Maximum Value	0.45	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

40 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	≥550	≥275	≥17	≥40	143~207	≥24
100＜d≤250	Sample Direction: Longitudinal	Normalizing + tempering	≥530	≥265	≥17	≥36	143~207	≥24
250＜d≤500	Sample Direction: Longitudinal	Normalizing + tempering	≥510	≥255	≥16	≥32	143~207	≥20
500＜d≤1000	Sample Direction: Longitudinal	Normalizing + tempering	≥490	≥245	≥15	≥30	143~207	≥20
d≤100	Sample Direction: Longitudinal	Tempering	≥615	≥340	≥18	≥40	196~241	≥39
100＜d≤250	Sample Direction: Longitudinal	Tempering	≥590	≥295	≥17	≥35	189~229	≥31
250＜d≤500	Sample Direction: Longitudinal	Tempering	≥560	≥275	≥17	-	163~219	-

• 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

China

Taiwan, China

Japan

South Korea

United States

International Organization for Standardization

Germany

France

Russia

United Kingdom

ISC

CNS

JIS

ASTM/AISI

UNS

ISO

DIN EN/DIN

W-Nr.

NF EN/NF

GOST

BS EN/BS

U20402

S40C

SM40C

1040

G10400

C40E4

C40E
Ck40

1.1186

C40E
XC42

C40E
080M40

2 Approximate Comparison Table

China	Japan	International Organization for Standardization	European Standard
GB	JIS	ISO	EN	Numerical Grade
40	S40C	C40	C40	1.0511

3 Approximate Comparison Table

China	Japan	International Organization for Standardization	European Standard
GB	JIS	ISO	EN	Numerical Grade
40	S40C	C40E	C40E	1.1186

4 Approximate Comparison Table

China	Japan	United States	International Organization for Standardization	Germany		France	European Standard		Russia	United Kingdom
GB	JIS	ASTM	ISO	DIN EN/DIN	W-Nr.	NF EN/NF	EN	Numerical Grade	GOST	BS EN/BS
40	S40C	1038 1040	C40 C40E4	C40 Ck40	1.0511	AF60C40 AF60C45 XC42HI	C40	1.0511	40	070M40 080M40 En8

5 Approximate Comparison Table

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 40	S40C	1040	ISO 630-1:1987 C40 C40E4 C40M2	C42 XC42	40	060A40

6 Approximate Comparison Table

China	United Kingdom
GB	BS EN/BS
40	080A42

40 Corresponding Standards(Same grade name, different standards)

1	GB /T 699-1999
	40 U20402 40#
2	GB /T 699-2015
	40 U20402
3	GOST 1050-1988
	40
4	GB /T 17107-1997
	40
5	GB /T 3078-2019
	40 40#
6	GB /T 710-2008
	40 U20402 40#
7	GB /T 711-2017
	40 40#
8	HB /Z 136-2000
	40
9	GB /T 13237-2013
	40
10	GB 3522-1983
	40

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