AISI M35 |1.3243 |SKH55 2018-11-06T12:40:47+00:00

Project Description

AISI M35 high speed tool steel manufacturers and suppliers, supplied in round bar,square bar,flat bar,plate,sheet and wire. AISI M35 steel is a medium-alloyed cobalt high speed steel,which is also called HSSE or HSS-E.It is similar with M2,but add more 5% cobalt which will increase hot hardness.M35 has good machinability,toughness,hardness,wear resistance and cutting ability. By virtue of these well balanced properties,M35 has come into very wide use for cutting tools.M35 high speed steel

1.Supply Form & Size & Tolerance

Round bar
ProcessCold DrawnHot RolledHot ForgedFree Forging
Flat bar
WidthMax 800mmMax 800mmMax 800mm
ProcessCold DrawnHot RolledHot Forged

Remark:Tolerance can be customized as per requests

2.Chemical Composition

ASTM A600M350.80-0.850.2-
DIN EN ISO 49571.32430.88-0.960.
JIS G4403SKH550.87-0.950.

3.Physical Property

Temperature °C
Modulus of Elasticity,kN/mm²230205184
Coefficient of Thermanl expansion from 20°C,10^-6_11.611.9
Thermal Conductivity,W/m °C242827
Specific Heat,J/kg °C420510600
Machinability (1% carbon steel)45.0 - 50.0%
CTE, linear,21 - 399°C, μm/m°C11.4
CTE, linear,21 - 593°C, μm/m°C11.5

4.Quenching Hardness

Hardness, Rockwell C (oil quenched from 1177°C, 5 mins)65.2HRC
Hardness, Rockwell C (oil quenched from 1204°C, 5 mins)65.2HRC
Hardness, Rockwell C (oil quenched from 1232°C, 5 mins)64.8HRC


Pre heat the AISI M35 with two steps.First,heat slowly and uniformly to 450-500°C with a rate not exceeding 220°C per hour,second,heat more quickly to the forging temperature of 950-1150°C.Re-heating is necessary when temperature below 950°C. Slow cooling in furnace after forging.


Annealing must be performed after hot working ,forging, or before re-hardening.Heat the temperature to 850to 900°C with a rate not exceeding 220°C per hour(one hour per 25mm of total thickness).Controlled slow cooling in furnace at 10 to 20°C per hour to approximately 600°C, followed by cooling in still air. The M35 annealed hardness achieved should be 260 Brinell or lower.

7.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 700°C, and  soak for approximately two hours,followed by slow cooling in the furnace.


Preheat M35 with two  steps ,first step with 450-500°C, holding 20~30 minutes per 25 mm. Second step with 850-900°C,then to the appropriate hardening temperature 1050°C – 1220°C.

Quenchant: By oil(40~60℃) , air or hot bath .


Tempering should be carried out immediately after quenching. Triple tempering is recommended for M35,heat slowly and uniformly to the tempering temperature 510-620°C,soak well not less than 2 hours per cycle(one hour per 25mm of total thickness). The minimum hardness is 64HRC.


10.Guidelines for Hardening&Tempering

Typical Application
Single- edge cutting tools, tool bits, form tools, etc1220°C560°C
Rotating multi-edge cutting tools, twist drills, saws,
milling cutters broaches, taps, etc.
1180°C – 1220°C560°C – 580°C
Tools for cold work applications, punching, blanking,
forming, cold extrusion, etc.
1050°C – 1150°C560°C – 590°C


AISI M35 is widely use in many applications,typical use as follow:

1.Forging Industry: Forging Dies, Cold Forming Tools
2.Cutting Tools: Hobs, Twist Drills, Milling Cutter
3.Screw Industry: Taps, Punches, Trimming Dies

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