Get in touch with Welong Company
Forged vs. Cast vs. Machined Bar-Stock — Factor by Factor
Select a factor to compare the three shaft-making processes side by side, based on the same criteria Welong uses to specify material and process against a drawing.
Comparison Factor
Target Standard
Forged Shaft
Cast Shaft
Machined Bar Stock
Internal Grain Structure
Continuous, follows part contour
Randomly oriented on solidification
Continuous but cut across at steps/shoulders
Typical Internal Defects
Minimal when properly forged
Shrinkage porosity, gas voids possible
None from process, but fiber flow interrupted
Fatigue Behavior (Cyclic Load)
Improved by continuous grain flow
Weaker due to porosity and grain discontinuity
Weaker at re-entrant steps than an equivalent forging
Governing Standard
ASTM A668/A668M (Class A–F carbon, G/H/J–N alloy)
Separate casting specs (e.g., ASTM A216/A217 families)
ASTM bar-stock specs (e.g., A29/A108 families)
Best Suited For
High-cycle, high-torque rotating shafts
Complex shapes, lower-cycle static loads
Simple shapes, lower unit cost at small sizes
