I have a job were I need to make up lots of hand operated punch dies, Well I have used 4130 in the past I`m wundering if 1018 with a good case hardening would work?
What is being punched?
To me, case hardening lots of anything is a real PITA, especially using Kasenit or something similar. You probably know the drill - heat the part red, dip or roll in the powder, reheat red & cold water quench (while splashing everything withing a three foot circle )
I need to make up lots
of hand operated punch dies...
Seems like it would be easier & more cost effective to use 4130 or 4140 prehard, around 30HRc. The case hardening is much harder, somewhere over 60HRc, so it's a question of do you really need the harder surface?
Do the punch and dies have to be torch hardened, or do you have a HT oven?
Case hardening isn't a bad way to go (except for the smell) in an oven; but, for a punch, and with only a torch, i'd use w-1. You can heat w/ torch and quench w1 in salt water and achieve close to 70 Rc,(on the case) if needed.
Another thing you might consider is how often will the punch and die need to be sharpened.
To sharpen the punch/die you will need to grind a few thousandths of the top of the die or bottom of the punch. This will enventually grind thru the case hardening and expose soft steel.
The material being punched and the clearance of the die will also have an effect on how fast the tooling becomes dull.
If these punches are going to be used for a long time, you would be better off using a tool steel.
I'd make them from A2, make a ton of blanks to the machined stage, have them all HT, grind up as needed, it is a thru hardening steel so you can heavily modify the dia and still be good to go.
I've mainly known s-7 for punch and die use in ironworkers. Very tough, and shock resistant. Case hardened 1018 might last a while, if this is a one-shot deal?
There for a pipe notcher. the punch is just a chunk of round rod 1" to 2" dia and about 3/4" thick, the dies are made from 2" to 3" bar or tube. I would just use 4130 like I have done in the past but around the seattle area I have not found tube stock in 4130. and when I have 200 dies to make and 600 punches I don`t feal like drilling 2" holes 6" deep unless I have to.
All there used for is notching tube up to .096 wall max