Tool Steel Selection for High-Speed Cutting Tools, Hobs & Broaches

Select high-speed steel by cutting speed, workpiece material, red hardness, abrasion resistance, tooth toughness, and edge chipping risk. For hobs, broaches, drills, milling cutters, and multi-edge cutting tools, the main choice is usually between toughness, hot hardness, wear resistance, and edge strength.

Quick Selection Guide by High-Speed Steel Grade

Choose the grade according to whether the tool is used for general cutting, hobs, broaches, difficult-to-machine alloys, or high-temperature cutting edges.

General HSS Standard

M2 High Speed Steel 1.3343 / SKH51

Recommended for broaches, gear hobs, drills, milling cutters, and general high-speed cutting tools.

Reason: M2 gives an economical balance of toughness, strength, and cutting ability for standard carbon and alloy steels.
Cobalt HSS Upgrade

M35 High Speed Steel 1.3243 / SKH55

Recommended when cutting tools need better hot hardness than standard M2 under more demanding cutting conditions.

Reason: M35 is a cobalt-bearing high-speed steel direction, selected when cutting heat and edge softening become more serious than in normal M2 applications.
Difficult Materials

M42 High Speed Steel 1.3247 / SKH59

Recommended for heavy-duty cutting of difficult-to-machine materials and high-strength heat-treated steels.

Reason: M42 provides higher cobalt-bearing hot hardness, helping the cutting edge resist softening under severe machining heat.

Selection Summary

This table gives a faster comparison when the buyer already knows the cutting tool type and main failure risk.

Cutting Tool ApplicationMain RequirementAobo Steel Grades
General broaches, gear hobs, drills, and milling cuttersBalanced toughness, strength, and cutting abilityM2
Large or complex multi-edge cutting toolsEdge strength and fracture toughness against interrupted cutsM2, M35
Cutting where heat softening becomes a problemHigher red hardness and hot hardnessM35, M42
Difficult-to-machine alloys and high-strength steelsHigh hot hardness and resistance to edge softeningM42
Applications where tooth chipping risk is highToughness and edge strength over maximum wear resistanceM2

Need High-Speed Steel for Cutting Tools, Hobs or Broaches?

Send your grade, size, quantity, cutting tool application, and workpiece material. Aobo Steel can support bulk supply of high-speed steel round bars and plates for industrial buyers.

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