Forged Flanges vs. Cast Flanges – Which One Should You Choose?

There are different manufacturing methods for flanges. The two main methods are forging and casting.

Forged flanges

Made by hammering or pressing heated steel into shape under high pressure.

The grain structure becomes dense and directional, following the shape of the flange.

Advantages: Very strong, no internal voids or porosity, excellent for high pressure and high temperature.

Standards: ASTM A105 (carbon steel forged), A182 (stainless/alloy forged).

Cast flanges

Made by pouring molten metal into a mold.

Advantages: Cheaper for large quantities, can produce complex shapes.

Disadvantages: May contain porosity, shrinkage cavities, or inclusions. Lower strength and impact resistance.

Standards: ASTM A216 (carbon steel cast), A351 (stainless cast).

Which to choose?

For critical applications (oil & gas, chemical, high-pressure steam) – always choose forged flanges. For very low pressure, non-hazardous water lines or drainage – cast flanges might be acceptable if cost is the only concern.

As a professional exporter, we supply only forged flanges for all pressure applications above Class 150. Safety comes first.