SPIRAL SHAPES. In general HSS drills are characterized by its spiral shape.

|   N-Type – Normal-Spiral.
Machining of materials of normal strength and hardness. Suitable for structural steel, cast irons, etc. Typical metal drills.

|   H-Type – Lang-drawn Spiral.
Machining of materials of high strength and high hardness. Suitable for short-chipping materials such as tempered steel.

|   W-Type – Short Spiral.
Machining of materials of low strength and low hardness. Suitable for long-chipping, soft materials such as aluminium, copper, etc.

ALLOYS. HSS-drills can be optimized by alloying them. Alloying tools is an appropriate measure for increasing their cutting performance, it offers a better chip removal and makes the tool more wear-resistant.

Chromium components as well als cobalt improve hardness and heat-resistance of the drills.

|   HSS-Co Drills.
For particularly tough and hard materials (corrosion-resisting steel). Cobalt content of up to 16%.

|   HSS-E Drills.
For materials of high strength, such as stainless steel. Cobalt content of up to 8% (M2).

|   HSS TiN-Drills.
Titanium-nitride-coated drills are particularly suitable for cutting steel and non-ferrous metals.

|   HSS-PM Drills.
High-speed steel (HSS) manufactured drills that are using powder metallurgical techniques, contain a higher part of alloy elements. Steel manufacturers are continiously developing new PM steel grades (e.g. PM HSS-E) to increase cutting capacity.