Shutoff in Plastic Injection Mould 

Shut-Off angle is applied for prevent the mold parts (Core and Cavity) from crashing into one another if there is any slight misalignment upon mold parts closing.

Shut-OFF angle also prevent galling that would occur if vertical metal faces were rubbing against each other.

Eg. 

Note:

A draft angle exists for purposes of part release, while a shutoff exists to prevent mold parts.

Shut-OFF angle also come there where Parting Line and Tooling direction of mold comes parallel.

Thin Steel in Plastic Injection Mould 

Thin Steel or Sharp Steel refers to areas of mold steel to be with thinner areas.

Why thin steel happens?

Incorrect part design. Small gap between walls of a plastic part.

Below are 2 examples:

Disadvantages of thin steels

When creating a plastic part or tool, thin steels should be avoided as much as possible. The disadvantages are:

• Shorten the plastic injection mould life

• Get mold technicians or machine operators hurt