S7 question

[Mark Nelson]

Can S7 be differential heat treated? Or should it?

 

[mete]

Since S7 is an air hardening tool steel it might be better to differentially temper rather than differentially harden.

 

[nhamilto40]

I'm sure you could differentially quench or temper S7 but there is probably no good reson to.

Using Crucible's data you could fully quench and then temper at say 400° F yielding a blade at 57 HRC and 125 ft-lb.

You would have to draw the spine to over 900° F to get it any tougher.

S7 Typical Properties

Tempering 	HRC  	 	Charpy ft-lbs
Temperature 
°F

300 	 	59 	 	85
400 	 	57 	 	125
500 	 	55 	 	125
600 	 	54 	 	115
700 	 	53 	 	105
800 	 	53 	 	105
900 	 	52 	 	120
1000 	 	51 	 	150
1100 	 	47 	 	190
1200 	 	41 	 	–

 

[Mark Nelson]

I read that at Crucible's web site.They also said that larger sections could be oil quenched to attain maximum hardeness, of course there idea of a large sction more then likely is large indeed. I thought that this might open up the the chance for S7 to be differential heat treated. Just wanted to get some opinions on the matter. I do fear that warping might be a issue. Thanks for the replys guys.