Making an int30 holder for serdi cutting system.

[minimutly]

Now I have my light weight, precision vertical mill, thoughts have been turning to cutting valve seats on it. Sure I could buy a Serdi machine with all its pilots, cutters, holders etc, but the last time I saw one it was £13,000.
So, I just bought a tip holder, and need to make one of these:-

Now, this is all very well, and I have some en40 steel shaft which I’d like to use. Question is, how suitable is it, assuming it’s not in a hardened state (I’ve been machining some of it previously and it was fine)?
I could machine it and then cherry red and quench, and then temper it down. Any comments on this? I’m sure I’ll get the usual suggestions to go and buy something more suitable that will cost me £100, but I’d rather use what I have - if you take this to it’s ultimate I could just buy the ones on eBay (assuming they are 30, not 40 int.
Will en40 work?
The cutter holder, slots into the arbor:-

 

[Agroshield]

Might I ask if it necessarily needs to be 30 INT at the top? Could you put a plain shank on it and hold in an ER collet or similar?

If you are using it infrequently and are the only one using it, it does not need to be hardened. Hardening gives better longevity on a 40h a week piece of tooling that is not treated with kid gloves by an employee.

If you heat treat it, there is a good chance it will move during the process, sending it out of true. Unless you have facilities to grind after hardening, it might be better left soft. At the least, look up the datasheet for EN40 and see what it says.

 

[Kram]

Havent used EN40 but sounds like plenty of chrome, so probably will want carbide or better. If the shaft is new stock, its likely in T condition, ready to machine and use. If your recycling scrap, it could have a very hard nitride case, but carbide or CBN or a grinder will go through it

As your part is just a holder I dont see the need for it being excessively hardened. It doesnt change the stiffness and chrome steels are relatively durable anyway.

Anneal temp is around 700c, but if you want to harden you need ~900c for this grade - a lot higher than normal carbon steel.

 

[minimutly]

Might I ask if it necessarily needs to be 30 INT at the top? Could you put a plain shank on it and hold in an ER collet or similar?

If you are using it infrequently and are the only one using it, it does not need to be hardened. Hardening gives better longevity on a 40h a week piece of tooling that is not treated with kid gloves by an employee.

If you heat treat it, there is a good chance it will move during the process, sending it out of true. Unless you have facilities to grind after hardening, it might be better left soft. At the least, look up the datasheet for EN40 and see what it says.

30 int gives it the closest fit to the spindle. I’ll have a think about going ER collet, but my intuition tells me not to.. Plus I don’t have any ER holders for my mill.
No, it hasn’t got to be hardened.
I’ll look up some more on en40 specs.