Punching is a cutting process in which material is removed from a piece of sheet metal by applying a great enough shearing force. Punching is very similar to blanking except that the removed material, called the slug, is scrap and leaves behind the desired internal feature in the sheet, such as a hole or slot. Punching can be used to produce holes and cutouts of various shapes and sizes. The most common punched holes are simple geometric shapes (circle, square, rectangle, etc.) or combinations thereof. The edges of these punched features will have some burrs from being sheared but are of fairly good quality. Secondary finishing operations are typically performed to attain smoother edges.The punching process requires a punch press, sheet metal stock, punch, and die.
Metal Cutting Skills
- Acuracy 98%
- Precision 95%
- Tolerance 90%
- Finishing 98%
- Wastage 10%
Piercing - The typical punching operation, in which a cylindrical punch pierces a hole into the sheet.
Slotting - A punching operation that forms rectangular holes in the sheet. Sometimes described as piercing despite the different shape
Perforating - Punching a close arrangement of a large number of holes in a single operation.
Nibbling - Punching a series of small overlapping slits or holes along a path to cutout a larger contoured shape.
Lancing - Creating a partial cut in the sheet, so that no material is removed.