Hss vs Cobalt End Mill: Which One Should You Buy?

Side by side

Specifications are manufacturer rated, as published on each listing and collected 1 November 2026.

What hss vs cobalt end mill means in practice

HSS stands for high-speed steel in these listings, and the LingGan examples state forged high-speed steel with surface hardness up to HRC62-66. Cobalt end mill, in these listings, means M42 cobalt: the Accusize and HHIP examples state M42 8% cobalt, and the HHIP example adds 68-70 HRC. The Accusize listing gives no hardness figure, so hardness alone does not settle the choice.

A figure from a listing describes that listing only: the HHIP example states a 9/16 in cutting diameter, while the LingGan examples state 3/4 in and 1 in cutting diameters.

Cutting diameter, shank, and flutes

Diameter sets the width of a slot the cutter mills, and the shank diameter must match the holder on your machine. Flutes are the channels that carry the cutting edges around the cutter: the Accusize example has 5 flutes, and the HHIP example and both LingGan examples have 4 flutes. No feed or speed figures are stated here, so flute count alone does not pick a winner.

Shank figures differ by listing: Accusize states a 1 in shank, HHIP states a 1/2 in Weldon shank, and both LingGan examples state a 3/4 in shank. Check the shank figure against your holder before ordering.

Hardness and coating

Hardness figures are stated for the LingGan and HHIP examples, and not for the Accusize example. The LingGan examples state surface hardness up to HRC62-66, while the HHIP example states 68-70 HRC with M42 8% cobalt. Coating is stated for 1 listing: the Accusize example states a TiAlN coating.

Materials and jobs

The LingGan examples list wood, aluminum, steel, titanium, foam, and plastic in their titles. The Accusize example is recommended for abrasive materials, with a smooth finish that often removes the need for a finishing cut for profiling and shallow slots. The HHIP example points to steel, stainless steel, and other harder materials, with center cutting for plunge cutting, slotting, and pocketing.

Choose HSS if

• You want a high-speed steel cutter in 3/4 in or 1 in cutting diameter.
• Your material list matches wood, aluminum, steel, titanium, foam, and plastic.
• You want 4 flutes with surface hardness up to HRC62-66.

Choose a cobalt end mill if

• You want M42 cobalt in the listing.
• You want a TiAlN-coated roughing cutter, as the Accusize example provides.
• You want a stated 68-70 HRC figure with center cutting.
• You want a 5 flute roughing cutter with a 1 in cutting diameter.

Project Match

• Wood, aluminum, steel, titanium, foam, and plastic: the LingGan HSS examples list all of these materials.
• Profiling and shallow slots: the Accusize finish often removes the need for a finishing cut there.
• Steel and stainless steel: the HHIP example points to these materials with center cutting.
• Abrasive materials and roughing: the Accusize example is recommended for abrasive materials.

FAQ: lasers and CNC

What is the difference between HSS and cobalt end mills?

In these listings, HSS means high-speed steel, and the cobalt examples are M42 cobalt. The LingGan HSS examples state surface hardness up to HRC62-66, while the HHIP cobalt example states 68-70 HRC, and the Accusize cobalt example states a TiAlN coating.

Which end mill is right for roughing?

The Accusize example is the roughing listing here: M42 8% cobalt, TiAlN coating, 5 flutes, and coarse tooth, with a finish that often removes the need for a finishing cut.

Can these end mills cut steel?

Steel is listed for the LingGan examples and the HHIP example. For the Accusize example, steel is Not stated.

What does center cutting allow?

Center cutting allows plunge cutting: the HHIP example lists plunge cutting, slotting, ramping, pocketing, and general milling. Center cutting is Not stated for the LingGan listings.

Are speeds stated for these end mills?

Speeds are Not stated in the listings in this set. Check the machine maker’s guidance for the material and cutter diameter before cutting.

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