Forging Ingots for Gear Blanks
Large gear blanks and pinions are forged from ingots, then machined and heat treated. Cleanliness and hardenability decide gear life, so case hardening and Ni-Cr-Mo grades are vacuum degassed.
Forging ingots for gear blanks are usually cast in grades such as SAE 8620, 20MnCr5 and EN24.
Typical components
- Large gear blanks
- Pinion blanks
- Ring gear blanks
- Gear shafts
Recommended steel grades
SAE 8620
A low carbon Ni-Cr-Mo steel that carburises to a hard surface over a tough core.
20MnCr5
A manganese-chromium case hardening grade used for automotive and industrial gears.
16MnCr5
A slightly lower carbon sibling of 20MnCr5, giving a tougher core after carburising.
EN24
A high strength, deep hardening steel with very good toughness, used where heavy sections must harden right through.
EN19
A widely used chrome-moly steel with good hardenability, toughness and fatigue strength in the quenched and tempered condition.
Choosing the ingot
State the case depth or through-hardness requirement so the right grade can be selected.
Check the ingot size chart for available marks and weights, and read how to choose the right ingot size using the forging reduction ratio.