W12Cr4V5Co5 T71245 - GB /T 9943-2008

Grade	W12Cr4V5Co5
China ISC	T71245
Corresponding Standard	GB /T 9943-2008 High-Speed Tool Steels
Classification	Tool Steel

W12Cr4V5Co5 Chemical Element Composition Content (%)

Component	C	Si ^①	Mn	P	S ^②	Cr	Ni ^③	Cu ^③	W	V	Co
Minimum Value	1.5	0.15	0.15	-	-	3.75	-	-	11.75	4.5	4.75
Maximum Value	1.6	0.4	0.4	0.03	0.03	5	0.3	0.25	13	5.25	5.25

① The lower limit of silicon content in electro-slag steel is not specified.
② Upon the request of the buyer, to improve the machinability of the steel, the sulfur content may be specified as 0.06% to 0.15%.
③ Cu and Ni are residual contents.

W12Cr4V5Co5 Mechanical Properties

condition	Heat Treatment or Condition	Hardness HBW
Delivery condition	Annealing	≤277
sample	Quenching and Tempering	HRC ≥65

Notes:
① When the tempering temperature is 550 to 570°C, temper twice, each time for 1 hour; when the tempering temperature is 540 to 560°C, temper twice, each time for 2 hours; when the tempering temperature is 530 to 550°C, temper three times, each time for 2 hours.
② For annealed and cold-drawn condition, the hardness may be allowed to increase by 50 HBW over the annealed condition.

New and Old Grade Replacement List

Corresponding Standard	Grade
GB /T 9943-2008	Grade China ISC
GB /T 9943-2025	Grade China ISC

1 Approximate Comparison Table High-Speed Tool Steels

China	Japan	South Korea	United States	International Organization for Standardization	Germany	United Kingdom
GB	JIS	KS	ASTM/AISI	ISO	DIN EN/DIN	BS EN/BS
W12Cr4v5Co5	SKH10	SKH10	T15	HS12-1-5-5	S12-1-4-5	BT15

2 Approximate Comparison Table High-Speed Steel 1

China	Japan	United States	International Organization for Standardization	Germany		France	Russia	United Kingdom
GB	JIS	ASTM	ISO	DIN EN/DIN	W-Nr.	NF EN/NF	GOST	BS EN/BS
W12Cr4V5Co5	SK H10	T15	HS12-1-5-5	S12-1-4-5	1.3202	Z160WKCV12-05-05-04	Р10К5Ф5	BT15

3 Approximate Comparison Table High-Speed Steel 2

China		Taiwan, China	Japan	South Korea	United States		Germany		France	Russia	United Kingdom
GB	ISC	CNS	JIS	KS	ASTM	UNS	DIN EN/DIN	W-Nr.	NF EN/NF	GOST	BS EN/BS
W12Cr4V5Co5	T71245	SKH 10	SKH 10	SKH 10	T15	T12015	S 12-1-4-5	1.3202	HS 12-1-5-5	Р10К5Ф5	HS 12-1-5-5 BT15

W12Cr4V5Co5 Corresponding Standards(Same grade name, different standards)

1	GB /T 9943-2008
	W12Cr4V5Co5 T71245
2	GB 9943-1988
	W12Cr4V5Co 5
3	GB /T 9943-2025
	W12Cr4V5Co5 T32720

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