Die or mould: which one does your part need?

Both are tools that make parts in quantity

A die and a mould are both made once and then used to produce many identical parts. The difference is what goes into them. A die usually cuts or shapes material that is already solid, such as a metal sheet. A mould is filled with material that is liquid or soft, such as molten plastic, rubber or metal, which then sets in the shape of the cavity.

When you need a die

Choose a die when your part starts as sheet or strip metal and is cut, bent, drawn or formed.

• Press tools and blanking dies: cut flat shapes and holes out of sheet.
• Progressive dies: do several steps one after another in each press stroke, for high quantities.
• Forming and drawing dies: bend sheet or pull it into cups and shells.
• Forging dies: shape hot metal under a hammer or press.

When you need a mould

Choose a mould when the part is made by filling a shape.

• Injection moulds: plastic parts such as covers, housings, caps and clips.
• Compression and transfer moulds: rubber parts and some thermoset plastics.
• Blow moulds: hollow plastic items such as bottles and cans.
• Die-casting dies: despite the name, these are moulds for molten aluminium and zinc.

Questions a toolmaker will ask

Expect questions about the part drawing, the material, the yearly quantity, the press or machine it will run on, the expected tool life and who will own the tool. Clear answers here get you an accurate price and a tool that lasts.

Not sure which one?

Describe the part, the material and how many you need, and add a photo or drawing. On Diemeco you can post it under the closest category, and die makers and mould makers who take that kind of work will see it and can suggest the right route.

Kinds of work

• Die making
• Mold making
• CNC machining
• Casting
• Fabrication