This guide supports Extramet’s carbide punches by answering the practical engineering and purchasing questions that usually come before an RFQ.

Quick Answer

  • Punch drawings should define working geometry and support geometry.
  • Small radii, flats, and shoulders can affect manufacturability and life.
  • Grade and finish should be selected around the material being punched.
Drawing detail Why it matters Spec tip
Working diameter Controls hole or formed feature State tolerance and finish
Shoulder/head Controls support Avoid sharp unsupported transitions
Tip geometry Controls entry and wear Define angles, radii, and flats
Grade Controls wear and toughness Match to application

Do not leave support undefined

A carbide punch needs more than a working diameter. Shoulder geometry, holder support, edge prep, and transitions affect breakage risk and service life.

Tip details matter

Pilot ends, straight punches, pierce punches, and forming punches all put different stress on the working end. Include radii, angles, flats, edge condition, and surface finish on the print.

The application guides the material

The punched material, thickness, lubrication, and production volume influence grade choice. A generic carbide grade may not be the best fit for every punch.

What to Include in an RFQ

  • working diameter and length
  • pilot or tip geometry
  • holder/support geometry
  • grade, finish, and quantity

Related Extramet Resources

Reviewed for technical accuracy: This supporting article was prepared to align with Extramet’s tungsten carbide manufacturing, grinding, inspection, and quality capabilities in Latrobe, Pennsylvania.

Frequently Asked Questions

What is a straight carbide punch?

It is a punch with a straight working body, often used when a consistent diameter or profile is required.

What makes a pilot punch different?

A pilot punch includes a geometry that helps guide or locate the operation before the working feature engages.

Why avoid sharp transitions?

Sharp unsupported transitions can concentrate stress and increase chipping or breakage risk.