Forged Crankshaft Tech

Ever wonder how a forged crank is made?
Here we take a look at materials, the forging process and hardening methods.
By Mike Mavrigian

A brief overview of how crankshafts are manufactured, including cast, forged and billet cranks.

FORGED CRANKSHAFTS: Aftermarket crankshaft manufacturers often employ their own proprietary formulas, but generally speaking, a steel ingot is heatedin an oven to about 2,200° F (at which point the steel is verymalleable/formable…not yet a liquid, but very easy to move around and shape). The hot ingot is then placed into a forging die and squeezed into the approximate shape of the desired crank profile. This “squeezing” is performed either by a hammering or pressing process. Either way, the goal is to compress the alloy mix not only to precisely fill the die, but also to increase the strength of the alloy by compacting the molecules and aligning and strengthening the grain structure.