Glossary of Terms

Bell radius

The bell radius of the wire drawing die is used to guide the incoming wire before centering in the approach angle.

Entrance angle

The entrance angle is used to direct the flow of lubricant into the wire drawing die approach angle where the lubricant is applied to the wire surface during drawing.

Approach angle

The approach angle is the most important section of a wire drawing die. This section of the die is where the reduction of area and lubricant compacting of the incoming wire takes place.


The bearing of a wire drawing die is the final control of the diameter of the drawn wire to guarantee its roundness, straightness, and surface finish.


Drawing dies are typically made of tungsten carbide or diamond and are used to reduce the diameter of wire.

Steel casing

Wire drawing dies are placed in a steel casing to hold the die and allow for easy die changes.

Back relief

The back relief area of a wire drawing die is designed to strengthen the exit of the die and prevent breakage of the insert.

Tungsten carbide

Tungsten carbide in its basic form is a fine gray powder, but can be pressed and formed into shapes for machinery, tools and other instruments.

Polycrystalline diamond (PCD)

Polycrystalline diamond is a synthetic diamond used for precision cutting.