Forging Ingot Grade Selection: Choosing Carbon, Alloy or Stainless
How to choose the steel grade for a forging ingot by section size, strength, toughness, hardening and service conditions.
Start from the service
List the load, temperature and environment: shock loading and fatigue favour alloy steels, high temperature favours chrome-moly, corrosion favours stainless.
Section size and hardenability
Heavy sections need deep hardening, so nickel-chromium-molybdenum grades such as EN24 and SAE 4340 are chosen for large shafts, while EN8 or C45 suit small and medium parts.
Case hardening or through hardening
Gears and pinions that need a hard surface over a tough core use case hardening grades such as SAE 8620, 20MnCr5 and 16MnCr5. Shafts and fasteners use through hardening grades such as EN19 and 4140.
Check equivalents
Quote the standard and edition on the order, because EN, SAE, DIN and JIS equivalents are approximate.
Related guides
EN, SAE and DIN Equivalents for Common Alloy Steel Grades
Approximate cross-reference between EN, SAE/AISI, DIN and JIS grades for common forging steels.
Ingot Selection for Open Die Forging: Mark, Shape and Hot Top
How to select a forging ingot for open die forging: work back from finished weight, then choose mark, shape, hot top and grade.
How to Order Forging Ingots: What to Specify
A checklist for buying forging ingots: grade, mark, shape, hot top, approvals, testing and delivery details to include in an enquiry.