04-03-2014, 05:32 PM
David,
Are they case hardened or thro' hardened?
If they are case hardened heating it to 700 C and allowing it to cool in air will soften it enough to turn it with normal inserts. It may still be hard.
Obvisouly using heat can cause some distortion and the heat needs to be localized - wet cloths with plenty of water will help.
If the idea of heat doesn't appeal cubic boron nitrite inserts (CBN) can be used, but CBN inserts can be expensive and the set up must be very rigid.
Once through the case hardened skin, the bar will be softer to do the threading, still will be harder than normal steel.
If it is thro' hardened without any form of heat treatment I think the only way would be to use CBN inserts.
DaveH
Are they case hardened or thro' hardened?
If they are case hardened heating it to 700 C and allowing it to cool in air will soften it enough to turn it with normal inserts. It may still be hard.
Obvisouly using heat can cause some distortion and the heat needs to be localized - wet cloths with plenty of water will help.
If the idea of heat doesn't appeal cubic boron nitrite inserts (CBN) can be used, but CBN inserts can be expensive and the set up must be very rigid.
Once through the case hardened skin, the bar will be softer to do the threading, still will be harder than normal steel.
If it is thro' hardened without any form of heat treatment I think the only way would be to use CBN inserts.
DaveH