HSS Milling Cutters: Types, Features and Applications in Machining

Posted by Ece Küçükoğlu on
HSS Milling Cutters: Types, Features and Applications in Machining

Widely used in machining operations, HSS (High Speed Steel) end mills are cutting tools that stand out for their high toughness, impact resistance and economical cost. With a more flexible structure than carbide tools, HSS milling cutters can be used reliably, especially in interrupted cuts and in standard-tolerance manufacturing processes.

Watch Temak Teknik’s informative video below covering HSS end mill types, flute counts, coating options and the benefits of regrinding:

Advantages and Key Features of HSS Milling Cutters

  1. High Impact Resistance and Toughness: Far less brittle than carbide end mills. They work reliably without tool breakage on machines with low rigidity and in interrupted or vibration-prone cutting operations.
  2. Low Cost and Easy Regrinding: Purchase costs are low. In addition, end and flank regrinding can be carried out easily and very economically on universal or compact end mill grinding machines.
  3. Versatility in Workpiece Materials: Ideal for machining mild steels ( < 180 HB), aluminium, copper, wood, plastics and composite materials.

Material Composition and Coating Options

  • HSS-Co (Cobalt HSS): Contains between 5% and 8% cobalt. The cobalt content increases the tool’s resistance to high temperatures and extends its cutting life.
  • Uncoated HSS Milling Cutters: Preferred uncoated and with extremely sharp cutting edges, especially when machining aluminium, copper and stainless materials, to prevent material from adhering to the tool (built-up edge).
  • Coated HSS Milling Cutters (e.g. Zirconium): Where high surface quality is required, special coatings are applied that reduce friction and delay wear.

HSS Milling Cutter Types by Flute Count and Form

  • Single-Flute Cutters: Used for cutting wood, acrylic, plastics and composite materials (on router machines) to evacuate chips rapidly.
  • 2- and 3-Flute Cutters: Preferred for machining aluminium and soft metals, and for keyway cutting (plunge milling) operations.
  • 4-Flute Cutters: Commonly used in general steel machining and side milling operations.
  • 6-Flute and Roughing (Serrated) Cutters: Either break chips into small segments to allow high metal removal rates (roughing), or deliver a precise surface finish thanks to their multi-flute design.
  • Form Cutters: Special profile types are available, including square (90° corner), ball nose (corner radius), tapered and special chamfering forms.