AISI M42 High Speed Steel

WALDUN is a top supplier in China for AISI M42 high speed steel. You can get round bar,square bar,flat bar,plate,sheet and wire.

AISI M42 High Speed Steel is a high cobalt toughness high speed steel, mainly used for high toughness precision wear resistant hardware cold stamping die, also can be used for cutting tools and knife in the cooling. Steel hardness is high, up to 70HRC, good thermal hardness, high temperature hardness, easy to grind. Cutting tools made of this steel can cut iron-based high-temperature alloys, cast high-temperature alloys, titanium alloys and ultra-high-strength steels, etc. However, the toughness is slightly poor, and the lower limit of temperature should be used when quenching. Because of the good grindability, it can be used to make various high-precision complex tools.

AISI M42 High Speed Steel SUPPLY FORM & SIZE & TOLERANCE

Round bar
Diameter	1-16mm	10-50mm	50-180mm	180-300mm
Process	Cold Drawn	Hot Rolled	Hot Forged	Free Forging
Flat bar
Thickness	1-2.5mm	1.5-20mm	20-300mm
Width	Max 800mm	Max 800mm	Max 800mm
Process	Cold Drawn	Hot Rolled	Hot Forged

Remark:Tolerance can be customized as per requests

AISI M42 High Speed Steel Chemical Composition per ASTM A600-92a

GRADE	C	Si	Mn	P	S	Cr	Mo	V	W	Co
M42	1.05-1.15	0.15-0.65	0.15-0.40	≤ 0.030	≤ 0.030	3.50-4.25	9.00-10.00	0.95-1.35	1.15-1.85	7.75-8.75

AISI M42 High Speed Steel PHYSICAL PROPERTY

Density，g/cm3	8.1
Modulus of elasticity,N/mm2	220x 10^3
Thermal conductivity,W/m °C	20
Specific heat,J/kg °C	429
Electrical Resistivity,ohm*mm2/m	0.52
Machinability	35-40% of a 1% carbon steel

AISI M42 High Speed Steel THERMAL EXPANSION

Temperature		10^-6 m/(m*K)	10^-6 in/in °F
°F	°C
212	100	11	6.2
392	200	11.5	6.5
572	300	11.9	6.7
752	400	12.3	6.9
932	500	12.4	7
1112	600	12.5	7
1292	700	12.5	7

AISI M42 High Speed Steel MECHANICAL PROPERTY

Hardness, Rockwell C(oil quenched from 1163°C, 5 minutes)	65.8
Hardness, Rockwell C (oil quenched from 1177°C, 5 minutes)	65.5
Hardness, Rockwell C (oil quenched from 1204°C, 5 minutes)	64.3
Izod impact unnotched (oil quenched at 1191°C; 510°C temper temperature)	13.6 J
Izod impact unnotched (oil quenched at 1191°C; 622°C temper temperature)	24.4 J
Poisson’s ratio	0.27-0.30
Elastic modulus	190-210 GPa

AISI M42 High Speed Steel FORGING

Pre heat the AISI M42 High Speed Steel with two steps.First,heat slowly and uniformly to 650-760°C with a rate not exceeding 220°C per hour,second,heat more quickly to the forging temperature of 1050-1150°C.Re-heating is necessary when temperature below 850°C. Slow cooling in furnace after forging.

AISI M42 High Speed Steel ANNEALING

Annealing must be performed after hot working and before re-hardening.Heat the temperature to 770 to 840°C with a rate not exceeding 220°C per hour(one hour per 25mm of thickness),soak for at least two hours. Controlled slow cooling in furnace at 10 to 20°C per hour to approximately 600°C, continue cooling to ambient temperature in the furnace or in air. Hardness after annealing 269Brinell, maximum.

AISI M42 High Speed Steel STRESS RELIEVING

It is recommended to stress relieve after machining and prior to hardening to minimise the possibility of distortion.Heat in a neutral atmosphere to the temperature of 600 to 650°C, and  soak for approximately two hours,followed by slow cooling in the furnace.AISI M42 High Speed Steel can be finish machined before heat treatment.

AISI M42 High Speed Steel HARDENING

Pre heat AISI M42 High Speed Steel uniformly to 780-840°C, transfer to the hardening furnace, (salt bath or controlled atmosphere furnace recommended) operating at 1170-1200°C, depending on the degree of hardening required for application, and the size of the tool. It is important that the temperature be accurately controlled to avoid overheating.After a short hold at the hardening temperature, quench the component without further soaking into salt at 540-595°C or warm oil. If salt quenched allow the component to equalise at the bath temperature and then complete the quench in still air.

AISI M42 High Speed Steel TEMPERING

Tempering should be carried out immediately after quenching. Heat slowly and uniformly to the tempering temperature 510-560°C,soak well not less than 2 hours(one hour per 25mm of total thickness).Triple tempering is required. Intermittent cooling, in air, between tempers is required for a minimum of 1 hour. Obtainable hardness of 67 to 69 HRC.

Triple Temper, °F	700	800	900	950	1000	1050	1100	1150
Rockwell C,Hardness	63	63.7	67.7	69.5	68.2	66.5	64.8	59.2

AISI M42 High Speed SteelAPPLICATION

AISI M42 High Speed Steel is a high-speed steel suitable for cutting tools,and widely used in metal manufacturing industries.

Typical use include:Twist drills, taps, milling cutters, reamers, broaches, saws, knives, and thread rolling dies.