Trimming and punching in machining can be carried out in a hot state or in a cold state. Usually, according to the temperature of the forging during trimming and punching during machining, it can be divided into hot trimming, hot punching and cold trimming. , Cold punching. Hot trimming and hot punching are generally machined after die forging using the waste heat of the forging. Cold trimming and cold punching are machined after the forging is completely cooled after die forging. So how should we choose hot trimming, hot punching and cold trimming and cold punching when machining workpieces? The specific selection principles are as follows:

1. Forgings with multiple pieces in one die and forgings weighing less than 0.5Kg are generally machined by cold trimming and cold punching.

2. Forgings with carbon content higher than 0.45 and weight less than 1Kg are machined by cold trimming and cold punching.

3. Forgings with carbon content higher than 0.45, multiple pieces per die and weights within 0.5Kg should undergo normalizing treatment to avoid cracks, and then perform cold trimming and cold punching for machining.

4. For large forgings, no matter what kind of steel material, they are machined by hot trimming and hot punching.

5. For trimming and punching that require thermal correction and bending processes, hot trimming and hot punching should be used for machining.

6. When the punch section is small and the skin is thick, hot punching should be used for machining, which can effectively prevent the punch from bending and breaking.

Strictly abide by the above 6 points on the selection principles of trimming and punching in machining, you can do more with less in machining, and can better avoid all kinds of damage to the workpiece and machining equipment.