• June 21, 2024
  • Shatou, Changan, Dongguan, CN
Billet, casting and forging processes

Billet, casting and forging: what’s the difference?

Billet, casting and forging are three different metal processing processes, and they all have certain differences in terms of process principles, advantages and disadvantages. For the metal fabrication industry, selecting the proper process method is critical to the quality and performance of the product.

1. Billet

Billet is a large piece of metal material made directly from molten metal by methods such as continuous casting and rolling. In continuous casting, molten metal is poured into a continuous-flow mold to form a long billet, which is then processed into billets of the desired shape and size through a rolling process. Steel billets are usually further processed during hot rolling, cold rolling, sawing, etc. to make various metal products. Billets are often used in CNC machining.


Billet shape

Billet shapes include round, rounded, flat, rectangular, hexagonal and hollow billets.

Billet common size

Size (mm)Type
100 x 100Square
120 x 120Square
140 x 140Square
160 x 160Square
200 x 200Square
220 x 250Rectangular
280 x 140Rectangular
300 x 160Rectangular
300 x 300Square
300 x 400Rectangular

Billet manufacturing has the following advantages and disadvantages:


– Billet is the form of metal in the initial stage, which can be further changed in shape, size and properties through subsequent processing processes.
– The billets can be processed at different temperatures with high flexibility.
– Billet cost is relatively low and suitable for mass production.


– Billets usually require further processing, such as forging or casting, to make them meet specific requirements.
– The surface quality of billets may be poor and surface preparation may be required in some applications.

2. Casting

Casting is the process of injecting molten metal into a mold, cooling and solidifying to form a metal piece of the desired shape. Casting can be divided into sand casting, metal casting, die casting and other methods, the most common of which is sand casting. In sand casting, molten metal is poured into a mold made of sand, and after the metal has cooled and solidified, the resulting metal piece is removed. Casting can create metal parts of complex shapes and can be used for mass production.


Cast manufacturing has the following advantages:


– Casting can manufacture parts with complex shapes with high production efficiency.
– Casting can manufacture large parts, such as engine blocks, aero engine parts, etc.
– Casting can be carried out at lower temperature and pressure, which avoids damage to materials caused by high temperature and high pressure processing.


– Defects such as pores and inclusions may occur during the casting process, which will affect the performance of the material.
– Casting has low dimensional accuracy and requires further processing to achieve accurate requirements.
– The mechanical properties of cast materials are poor, such as tensile strength, fatigue resistance, etc.

3. Forging

Forging is a process in which metal materials are heated to a high temperature state and then plastically deformed by impact or pressure under the action of force. Forging can process metal materials into various workpieces that require high strength and wear resistance, such as forgings, shafts, etc. Forging can usually be divided into free forging, die forging, cold forging and other methods, the most common of which is hot die forging. In hot die forging, a metal material is heated to a high temperature, placed in a mold, and deformed plastically under pressure to obtain a metal part of the desired shape and size.


Forging manufacturing has the following advantages:


– Forging can increase the compactness and mechanical properties of the material, giving it better strength and wear resistance.
– Forging can make parts of various shapes and sizes, such as forgings, shafts, connecting rods, etc.
– Both the grain structure and the fibrous morphology of the forged material are improved, increasing the service life of the material.


– Forging requires high temperature and pressure, and the processing process is relatively complicated.
– Forging costs are higher and require longer processing cycles.
– Forging is generally suitable for small batches and is less economical for large batches.

Which one is better for my needs?

Billets are suitable for needs that require further processing, such as cutting, drilling, grinding, etc.; casting is suitable for needs that require complex shapes and mass production; forging is suitable for needs that require high strength and wear resistance. Choose the appropriate processing method according to your specific needs.

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