What is Tool Steel

1. Tool Steel Definition

Tool steel contains various amounts of tungsten, molybdenum, cobalt and vanadium to improve the heat resistance and durability of the metal. This makes them ideal for cutting and drilling.

2.Tool steel grades and corresponding applications

Depending on the composition of the tool steel, the temperature range of forging or rolling, and the type of quenching, the grade of tool steel is wide. The general grades of AISI-SAE tool steel are O1, A2, and D2. These standard grades are considered "cold work steels" and can maintain their cutting edges at temperatures up to about 400 ° C. They have good hardness, wear resistance and deformation resistance.

O1 Tool Steel

O1 is an oil hardened steel with high hardness and good machinability. This grade of tool steel is mainly used for cutting tools and drill bits as well as knives and forks.

O1 mould steel
O1 is an oil quenching (cold work) die steel that can be quenched at relatively low temperatures.
O1 has the characteristics of deep hardening and high toughness. If higher wear resistance is required, other materials may be considered, such as air hardening A-2 or 0-2.
The workability grade of 0-1 is 65% to 75% of 1% carbon tool steel.
O1 sold in annealed state. Typical annealing hardness is BHN 187/221 Rc 10/18.
The maximum working hardness of 0-1 is BHN 722 Rc 64.
O1 can meet the requirements of ASTM-A681.
typical application
Blanking die / forming die / gauge / trimming die / spindle / collet
Chemical composition (typical value)
Carbon: 0.90% Silicon: 0.30% Manganese: 1.20% Chromium: 0.50% Tungsten: 0.50%

A2 Tool Steel

A2 is an air hardened steel containing a moderate amount of alloy material (chromium). It has good workability and a balance between wear resistance and toughness. A-2 is the most commonly used air hardened steel variety, usually used for blanking and forming punches, trimming dies and injection dies.

A2 is an air hardening (cold work) tool steel, and its wear performance is between 0-1 oil hardening and 0-2 air hardening.
A2 has good toughness, medium wear resistance and relatively easy machining. A-2 also has excellent non-deformation properties. These characteristics make A-2 a very popular and widely used material.
The machinability grade of A-2 is 65% of 1% carbon tool steel.
A2 is sold in annealed condition. Typical annealing hardness is BHN 197/241 Rc 12/22.
The maximum working hardness of A-2 is BHN 698 Rc 62.
A-2 can meet the requirements of ASTM-A681.
typical application
Blanking die/Compression mold / forming mold / trimming mold / die / drill sleeve / gauge / lamination mold
Chemical composition (typical value)
Carbon: 1.00% Silicon: 0.30% Manganese: 0.40% Chromium: 5.00% Molybdenum: 1.00% Vanadium: 0.20%

D2 Tool steel

D2 steel can be oil hardened or air hardened, and contains a higher percentage of carbon and chromium than O-1 and A-2 steels. After heat treatment, it has high wear resistance, toughness and low deformation. The higher carbon and chromium content of D-2 steel makes it ideal for applications requiring longer tool life.

D2 is a high carbon and chromium air hardening (cold work) tool steel.
D2 has excellent wear resistance and can be used in long-term applications requiring wear resistance. 0-2 can be processed in the annealed state. 0-2 represents the minimum deformation during heat treatment.
The 0-2 ass sub-workability grade of 1% carbon tool steel is 35% 10 40%.
D2 is sold in annealed condition. Typical annealing hardness is BHN 217/229 Rc 17/18.
The maximum working hardness of D-2 is BHN 710 Rc 63.
typical application
Stamping die / forming roller / forming die / punch / die / trimming die / label die / wear plate
Chemical composition (typical value)
Carbon: 1.50% Silicon: 0.30% Manganese: 0.40% Chromium: 12.00% Molybdenum: 1.00% Vanadium: 0.90%

Other tool steel grades contain a higher percentage of different types of alloys, such as high-speed steel M2, which can be selected for mass production. Various hot-worked steels can maintain sharp cutting edges at higher temperatures up to 1000 ° C.

3. Equivalent Too Steel from different coutries Standards.

Equivalent Tool Steel Specifications
Great	U.S.A	Germany	Italy	Japan	France	Spain
Britain BS4659	AISI/SAE	W-Nr Din	UNI	Jis	AFNOR	UNE
B01	O1	1.251	95MnWCr5KU	SKS3	90MnWCrV5	F.5220
		100MnCrW4			90MWCV5	95MnCrW5
BD2	D2	X155CrVMo12-1	X155CrVMo121KU	SKD11	X160CrMoV12-2832CDV12-28	F.520A
BD3	D3	1.208	X205Cr12KU	SKD1	X200Cr12	F.5212
		X210Cr12			Z200C12	X210Cr12
BD6	D6	1.2436	–	–	–	–
BA2	A2	1.2363	X100CrMoV511KU	SKD12	X100CrMoV5Z	F5.227
		X100CrMoV5-1			100CDV5	X100CrMoV5
BH13	H13	1.2344	X40CrMoV511KU	SKD61	X40CrMoV5	F.5318
		X40CrMoV5-1			Z40CDV5	X40CrMoV5
BS1	S1	1.255	55WCrV8KU	–	55WC20	F.5241
		60WCrV7				45WCrSi8
BP20	P20	1.2311	–	–	–	–
		40CrMnMo7
–	420	1.2083	–	SUS420J2	X40Cr13	–
		X42Cr13			Z40C14
~BP30	–	1.2767	~42NiCrMo157	SKH51-	~Y 35NCD16	–
		X45NiCrMo4
BM2	M2	1.3343	–	–	Z85WDCV	–
		S6 502			06-05-04-02
BM42	M42	1.3247	HS2-9-1-8	SKH59	Z110DKCWV
		S2-1-1-8			09-08-04-02-01
BW2	W2	1.2833	–	–	105MV01	–
BS1407	–	1.2002	–	–	120C2	–