The process of metal stamping

2024-08-02 13:04:03

Metal stamping, known also as pressing, is a process where flat sheet metal in the form of blanks or coils are placed in the stamping press. In the press, a tool and die surface the tool and die on the press give the desired shape to the metal.

Before shaping the metal in the press, the tooling has to be custom designed as per the product specifications using computer aided design and manufacturing or CAD/CAM technology. These designs need to be precise to make sure that the punch and bend retain proper clearance as well as optimal part quality. A 3D model of a tool can have hundreds of parts, making the design process complex and intricate.

After the custom tool is designed through CAD/CAM, the metal stamping manufacturer uses various manufacturing methods including Machining, wire EDM and grinding to complete the stamped metal parts production.

The various processes used in metal stamping include:

Blanking — Blanking involves cutting a rough shape or outline of the desired product. Experienced and reputable custom metal stamping manufacturers in China focus on minimizing burr or rough edges on the metal at this stage. Burrs can drive up the lead time and the cost of making the part. The hole diameter, which is the spacing between hole and edge as well as geometry, is determined in this stage. The workpiece or blank is removed after it is shaped from the sheet metal, giving the desired blank.

Punching — This process involves removal of scrap material from the workpiece as opposed to blanking where the workpiece is removed from the sheet metal.

Bending — When bends such as L, U or V shapes are required in the part, the manufacturer uses bending techniques to create the shapes.

Flanging — In this, specialized flanging machinery or dies are used to introduce flange or flare in the part. Flanging is also a type of bending where a ‘flange’ is created which is different from bends as the dimension of the bends are smaller than the part. Flanging gives a better finished appearance and provides edge strengthening and rigidity.

Coining — In this the workpiece is positioned between the die and press. The metal is penetrated into by the tip of the punch to create accurate and repeatable bends.

Embossing — Embossing creates the desired raised or recessed design in the metal.

Metal stamping machines can go above just stamping and can punch, cut, cast, as well as shape metal sheets. Machines can be numerically controlled by computer or programmed to offer repeatability and high precision of each stamped piece.