Introduction

One of the most basic parts of the mold is the mandrel, which is generally made of steel. The upper part of the mandrel is made of a step so that it can be placed in place by the mandrel holder. Mandrels are plated by heat treatment after manufacturing. After hardening (heat treatment), their strength has increased in terms of abrasion, but due to long-term use, it will lose its sharpness, which will return to its original state after being slowed down by industrial machines such as magnet stone.