M35 High Speed Steel Round Bar 1.3243 / SKH55

M35 High Speed Steel Round Bar 1.3243 / SKH55

Categories:Steel Bars

Model No.:M35

Shape: Round, Square, Flat, Plate…

Round: Dia 3mm-300mm.
Square/Flat: Th 3-120mm x W 3-300mm.
Plate: Th 1-60mm x W 10-810mm.

Surface condition: Smooth, Peeled, Turned, Grinded, Polished, Milling, Black…


M35 High Speed Steel Round Bar 1.3243 / SKH55


M35 High speed steel round bar suitable for cutting tools such as, broaches, taps, milling, reamers, hobs, shapers cutters, saws, etc.
M35 High speed steel round bar is also suitable for cold work applications, where exacting demands are imposed on wear resistance. The steel possesses an admirable combination of wear resistance and toughness and in these respects superior to the high alloyed cold work steels.

Quality Standard

-ASTM A600 Standard for High Speed Tool Steel.

-JIS G4403 standard for High speed tool steels.

-BS EN ISO 4957 for Tool Steel.

All Grades Comparison

ASTM                       DIN                          EN                             JIS                             GB

M35                        1.3243                 HS6-5-2-5                   SKH55              W6Mo5Cr4V2Co5

Chemical Composition(%)

Steel GradeCSiMnPSCrMoVWCo
M350.88-0.950.40 max0.40 max0.030 max0.030 max3.80-4.504.75-5.201.75-1.906.00-6.704.60-5.00
1.32430.87-0.950.45 max0.40 max0.030 max0.030 max3.80-4.504.70-5.201.70-2.105.90-6.704.50-5.00
W6Mo5Cr4V2Co50.87-0.950.20-0.450.15-0.400.030 max0.030 max3.80-4.504.70-5.201.70-2.105.90-6.704.50-5.00

Heat Treatment


M35 High speed steel round bar is supplied in the annealed and machineable condition. Re annealing will only be necessary if the steel has been hot worked, forged, or hardened by the toolmaker. Heat the M35 hss bar high speed steel to 850°C at a rate of no more than 220°C per hour. Always hold at temperature for one hour per 25mm of thickness (with two hours being minimum). Furnace cool slowly. The M35 hss bar annealed hardness achieved should be 260 Brinell or lower.

Stress Relieving

If tools produced from M35 High speed steel round bar is heavily machined or ground it is recommended to stress relieve after machining and prior to hardening to minimise the possibility of distortion. To stress relieve heat the component to 600-700°C and soak well (approx 2 hours) Cool slowly in the furnace. The tools can be finish machined before heat treatment.


For best results harden in a vacuum or controlled furnace, or in a properly rectified salt bath. Pre heat thoroughly in two steps to 450-500°C, then to 820-870°C, transfer to the high temperature salt bath or furnace. The exact hardening temperature to use for M35 hss bar will depend on the type of work being treated, but in general components should be hardened from the range of 1050-1250°C.


M35 High speed steel round bar components can be tempered between 510-620°C. Triple tempering is recommended with a minimum of two hours at temperature per cycle. The component should be cooled in still air to room temperature between tempering treatments.
Temperature [°C] 540 560 580
Hardness [HRc] 67 66 65


500 ton per month.


Chemical Composition, Mechanical Property, Hardness testing, Ultrasonic testing, Metallographic, Dimension and Surface.


Each bundles of max 2,000kg with several steel strips, Two tags on each bundle, Wrapped in waterproof paper, PVC sleeve, and sackcloth with several steel strips.

Mill’s Test Certificate

EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.

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