← All products
HEX Square End Mill for Hardened Steel HRC60–68

HEX Series End mill for hardened steel

HEX Square End Mill for Hardened Steel HRC60–68

Range reference: KVX-015

workpiece material
Hardened Steel
application type
Semi-Finishing; Finishing
flute type
Square End Mill
Coating
DR3

• Carbide: Ultra-fine grain carbide, 0.4 μm, 9% Co • Coating: Balzas DR3, heat resistance up to 1300°C • Hardness Range: HRC 60–68 • Core Diameter: Up to 68% for high rigidity • Helix Angle: 45° • Negative Rake Angle: 0° to -5° • Application: High-efficiency side milling & finishing

Enquire about this tool →

Technical data




HEX square end mills use ultra-fine carbide with 0.4 μm grain size and 9% cobalt content. This carbide substrate provides high hardness, excellent wear resistance, and enough toughness for high-hardness steel machining.

It helps the tool maintain edge strength and cutting stability when machining hardened steel materials where ordinary carbide end mills may wear quickly or suffer from edge chipping.




The cutter is coated with DR3 high-wear-resistant coating, with heat resistance up to 1300°C. This coating helps improve oxidation resistance, reduce friction, and extend tool life during continuous cutting of hardened steel.

For HRC60–68 machining, cutting temperature and tool wear are usually critical problems. The DR3 coating helps the tool maintain stable performance under high-temperature and high-load cutting conditions.


The HEX square end mill adopts a large core diameter design of up to 68%, improving tool rigidity and edge support. This helps reduce tool deflection and vibration during side milling, shoulder machining, and high-speed finishing.

Higher rigidity is especially important when machining hardened steel, because unstable cutting can easily lead to poor surface finish, edge damage, or shortened tool life.




The tool uses a 45° helix angle together with a 0° to -5° negative rake angle. This geometry helps improve cutting stability, strengthen the cutting edge, and reduce the risk of micro-chipping in hardened steel machining.

The negative rake design is especially suitable for high-hardness materials where edge strength is more important than aggressive cutting sharpness.

Additional technical data

Machining TaskWhy HEX Square End Mill Fits
Side millingLarge core design improves rigidity and cutting stability
Shoulder machiningStrong edge support helps reduce micro-chipping
Flat surface finishingStable geometry supports better surface consistency
Contour finishing45° helix angle helps achieve smoother cutting
Hardened steel finishingDR3 coating improves wear resistance under high cutting temperature
Precision mold machiningNegative rake design improves edge strength and dimensional stability

Additional technical data

ItemRange / Notes
Tool typeSquare end mill / flat end mill
Hardness rangeHRC60–68
Diameter rangeD1.0–D25.0
Length optionsStandard length and long shank options available
Typical useSemi-finishing, finishing, high-speed machining
Custom serviceDiameter, flute length, overall length, shank, coating, and special geometry

Technical notes

Technical illustrations and dimension data

Product Overview
carbide end mill for hardened steel machining.png
Product Features
hardened steel end mill material and coating.jpg
Product Features
hardened steel end mill design.png