View Full Version : Need Help! Machining P20 Pre-toughened Steel ??

05-11-2011, 01:40 PM

Have a fairly simple hanger mould to machine but it is out of P20 36mm thk (pretough steel) which i have no experience of machining .

So if any one could give some metric pointers(speeds etc) that would be very much appreciated .

Tools i need to use are :

6mm carbide 4flute

3mm reamer for ejector holes

2.8 jobber hss for the above

8mm stub hss drill

Then i 'll be sparking the rest



08-24-2011, 10:59 AM
P20 Prehard is a very easy steel to machine. it is no different them machining most other tool steels except that if you heat it up to much, you can actually "spot-harden" the material as you are machining it, and if you do you will have a hard time getting through the hard spot after.. Use air for machining - coolant for drilling.... take it easy and you will do fine!