How to Select a Forging Material
Most over-specification in Indian engineering comes from choosing a grade by reputation instead of by load case. This guide walks the decision the way our engineering team does it when a customer's drawing arrives without a grade called out.
- Load Type
- Static, fatigue, impact, wear
- Section Size Rule
- Above 60 mm consider EN19
- Wear Strategy
- Case or induction harden, don't over-alloy
- Cost Order
- EN8 < 1045 < EN19 < EN24 < stainless
- Corrosion
- Stainless only where actually needed
- Support
- Free grade recommendation with your drawing
How to Select a Forging Material at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Load Type: Static, fatigue, impact, wear
- Section Size Rule: Above 60 mm consider EN19
- Wear Strategy: Case or induction harden, don't over-alloy
- Cost Order: EN8 < 1045 < EN19 < EN24 < stainless
- Corrosion: Stainless only where actually needed
- Support: Free grade recommendation with your drawing
Step One: Define the Load Case
Static load, fatigue load or impact? Fatigue governs most forged parts and needs a clean, tough grade. Pure static strength is cheaper to buy. Impact loading demands toughness and rules out high-hardness grades outright.
- Static: cheapest adequate grade
- Fatigue: clean grade, good toughness
- Impact: toughness over hardness
- Wear: hard surface, tough core
Step Two: Check Section Size
Hardenability, not strength, decides thick-section grades. EN8 in a 100 mm section gives a soft core no certificate will show. Above roughly 60 mm requiring uniform properties, move to EN19; above 150 mm, to EN24.
Step Three: Separate Surface From Body
If only the surface wears, do not harden the whole part. Induction hardening EN8, or carburising 20MnCr5, gives a hard skin over a tough core at lower cost and lower risk than through-hardening an alloy grade.
A Grade Selection Matrix
Material selection becomes straightforward once the governing failure mode and the section size are known. The matrix below is the starting point our engineering team uses; it is a guide to the sensible first choice rather than a substitute for design calculation.
| Duty | Thin to moderate section | Heavy section |
|---|---|---|
| General, lightly loaded | EN8 / SAE 1045 | EN19 |
| Fatigue loaded | EN19 | EN19 or EN24 |
| Shock loaded | EN8 or EN19 | EN24 |
| Surface wear, tough core | EN8 induction hardened | 20MnCr5 carburised |
| Gear teeth | 20MnCr5 / 16MnCr5 | EN353 |
| Rolling contact | EN31 | EN31 |
| Corrosion, no chlorides | SS 304 | SS 304 |
| Corrosion with chlorides | SS 316 | Duplex |
| Corrosion plus hardness | SS 410 | SS 410 |
How to Write the Material Call-Out on a Drawing
Most material disputes trace back to an incomplete call-out rather than to a disagreement about metallurgy. A complete specification names the grade with its standard, states the delivery condition, gives a hardness or strength band rather than a single figure, and says where hardness is to be measured. For surface hardened parts it also states case depth and the hardness at which case depth is measured. Anything omitted is decided by whoever is holding the part.
- Grade and standard, e.g. 42CrMo4 to EN 10083-3
- Delivery condition, e.g. +QT, +N or annealed
- Hardness or strength band with the measurement scale
- Where hardness is measured on the part
- Case depth and its measuring hardness, for hardened surfaces
- Certification type, such as EN 10204 3.1
The Cost Ladder, and Why Over-Specification Backfires
Material cost rises roughly in the order EN8, SAE 1045, EN19, EN24, case hardening grades, then stainless and duplex — but the price of the steel is only part of the picture. Harder and more alloyed grades machine more slowly, distort more in heat treatment and weld less readily, so an unnecessary upgrade adds cost in three places at once. A correctly selected EN8 part that is properly heat treated will outperform a badly heat treated EN24 one every time. Send the drawing with the load case and environment and we will recommend a grade with the reasoning, free of charge with your enquiry.
People also ask
Will you recommend a grade if our drawing does not specify one?
Yes, free with your enquiry. Send the drawing with the load case and environment and we will propose a grade and heat treatment with the reasoning.
Is it safer to over-specify the grade?
No. Over-alloying reduces machinability and raises distortion and cracking risk without improving the property that actually governs the design.
Topics covered on this page
- forging material selection guide
- how to choose steel grade forging
- forging steel grade comparison India
- forging material consultancy
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
Which grade should I choose for a shaft?
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EN8 for light duty, EN19 for loaded shafts above 60 mm section, EN24 for very large or shock-loaded shafts, SS 410 where mild corrosion resistance is also needed.
Will you recommend a grade for our drawing?
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Yes. Send the drawing with the load case and environment, and our engineering team will propose a grade and heat treatment with reasoning.
Is a more expensive grade always safer?
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No. Over-specifying alloy grades can reduce machinability and increase distortion risk without improving the property that actually governs the design.
How do I know the supplied material is correct?
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Every heat lot is spectro-verified on arrival at our plant, and results are reported against the mill certificate.