Printed from Kezuriba (kezuriba.net/en/troubles/material-hardened-steel/)

Hardened steel (high-hardness steel) quirks

Material-specific problems TurningMillingDrilling

Check first

Very hard, so the tool wears quickly
Heat treatment may leave the surface especially hard, so beware of boundary damage
Thrust force is large and compressive stress is applied to the cutting edge, so flaking tends to occur

Try first

For flaking, reduce the feed and cutting speed
Select a cutting edge that resists impact and a heat-resistant tool material
Secure sufficient rigidity of the tool, fixture, and machine

?Likely causes

Very hard, so the tool wears quicklyOne maker^[1]
Heat treatment may leave the surface especially hard, so beware of boundary damageOne maker^[1]
Thrust force is large and compressive stress is applied to the cutting edge, so flaking tends to occurOne maker^[2]

✓Fixes

Cutting conditions

For flaking, reduce the feed and cutting speedOne maker^[2]

Tool

Select a cutting edge that resists impact and a heat-resistant tool materialOne maker^[1]

Setup

Secure sufficient rigidity of the tool, fixture, and machineOne maker^[1]

↔Related problems

Stainless steel quirks (work hardening, welding, boundary wear)Aluminum alloy quirks (welding, built-up edge, chips)Titanium and titanium alloy quirks (heat, welding, ignition)Cast iron quirks (powdery chips, edge chipping, black scale)Heat-resistant alloy (Ni-base alloy, etc.) quirks Magnesium alloy quirks (chip ignition)Copper and copper alloy quirks Mild steel (low-carbon steel) quirks

📚Sources

Causes and fixes are summarized in our own words from cutting-tool makers’ troubleshooting guides and technical data. “Agreed by 2+ makers” means two or more makers say the same thing.

Mitsubishi Materials — Workpiece material applications: H series mmc-carbide.com
Mitsubishi Materials — Advanced workpiece materials: Causes of tool damage mmc-carbide.com