Nonmetallic Die Materials

Wood and Hardboard Laminates 

Hardwood can be used for form blocks, but laminated impregnated wood, hardboard and 

plastics have largely replaced it.  Hard maple and beech are good woods for  die 

applications if they are carefully selected for close grain structure. 

High-density panels composed of compressed wood fiber and lignin are used for jigs, 

dies, fixtures, templates, patterns and molds.  This  is  a cellulose semiplastic

material available in various thicknesses finds application as both a jig and tooling

material.  It can be readily laminated  with cold-setting adhesives.  Such wood-based 

materials are suitable for short run dies for prototype work.  Such dies are also widely

used in the aircraft industry.

Rubber 

Molded rubber female dies  and rubber-covered punches are  used  in difficult forming

operations, such as the production of deeply fluted lighting reflectors.  Many types of 

rubbers and rubber compounds are used.  Natural rubber, neoprene and polyurethane all 

find application in pressworking. 

Specifications for rubbers used in the conventional Guerin, Marform and Hydroform 

processes are determined by the performance  needed for the process.  Some rubber 

compounds, especially polyurethane can be  cast in place and cured to form the needed 

shape.  This permits the economical production of forming die components, part 

strippers, pressure pads and non-marring automation fingers in the toolroom. 

Cork

Soft, medium and hard cork layers, compressed into sheet form are sometimes used with, 

or in place of, rubber pads.  Cork deforms only slightly in any direction other than that of 

the applied load, while rubber flows in all directions.  

Plastics

Like wood, the pressures involved in the process limit the use of plastic materials for 

dies.  Selection of plastics is based on economy relative to die life expectancy.  Draw 

radii are a primary source of concern because maximum loads and abrasion occur in these 

areas. 

Draw dies having a metal core of either ferrous or zinc-alloy materials, capped with a 

working face of epoxy, are used in the  aircraft, appliance and automotive industries. 

Rubber forming dies are made of combinations of cast and laminated epoxy applied to a 

heavy steel base. 

Polyester resins are used for low volume tooling.  The chief advantage this material has 

over the stronger and more stable epoxy resins is cost. 

Polyurethanes

Polyurethanes combine many of the good properties  of  both elastomers and plastics. 

They have demonstrated a unique combination of abrasion resistance, tensile strength and 

high load bearing capacity not available in conventional elastomers plus impact resistance 

and resilience not available in plastics. 

Because of their liquid, uncured form and their excellent cured properties, these polymers 

are useful in draw dies, drop-hammer dies, forming and stamping pads, press-brake 

forming dies, mandrels, expanding punches and other tool design applications. 

A major use of this material is for die  automation components such as kickers, lifter 

heads  and rollers  where  the  excellent wear-resistance of the material, together with its

non-marking characteristics are very useful.  Polyurethane is available as a two-part liquid 

formulation  that can  be  mixed  and  cast in place to form custom made die pads and 

transfer automation jaws.