Forged 4140 to Simalar Metal

[Ryan9]

If machining a billet piece, what would be the most similar metal to Forged 4140. Ductility is critical.

I am considering 4340 and then heat treating it for stress relief

 

[tedg]

If cost is the prime consideration, your suggested move might do.

If quality and precise heat treat aim at max. fracture toughness is more important than low cost, youmay want to look into maraging steel.

Would require more information about your application and the size of billet you need.

Good luck