FREE Injection Mold SampleI hope the end of the year is treating you well. We have had a few conversations with customers recently regarding shut off angles, and I wanted to get one final post out to everyone this year to briefly discuss the subject.

A shut off angle is where two parts of the mold shut against each other to prevent plastic from passing through. This term applies where one part of the mold closes against another to form a slot or hole, or it is sometimes used to refer to the interface where a slide shuts against a core or cavity. Sometimes, the shutoff surfaces are parallel to the direction that the mold opens. When this happens, draft has to be added to avoid grinding the parts of the mold against each other. A 3 – 5 degree draft is ideal for these shutoff areas and will ensure the life of the mold. Without this amount of draft the mold will get damaged, and may potentially even “lock up” and not open. Even with hardened steel, lack of draft in this area will ruin the mold.

Understandably, many customers do not understand why we ask for this draft, but without it, every time the mold opens and closes, the steel will wear out in this area in a very short time. When this happens, repairs can be costly.

If you have any questions regarding this or any other injection molding information, please send us an email or give us a call at (770) 901-3200. Thanks, and Happy Holidays.