temprature for tempering old nicholson file?

M

MJ.

Joined
May 1, 2014
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just wondered if anyone could help? tried my usual method for tempering old files using a blow torch as the oven never seemed to get them soft enough but have made this one too soft... im going to re heat treat tomorrow and try again in the oven
its the first nicholson file i've worked with... any help with correct tempering tempratures for old nicolson files would be great...
 
Assuming you reach full hardness in the quench, I'd suggest starting at 450f for 2 tempering cycles, then sharpen and test for brittleness... you may need to go hotter to get an edge that doesn't want to chip. I do not recommend tempering with a torch unless you are trying for a soft-back draw.
 
Look for temps for 1095 or W1. 400f is a great place to start. Might have to go as high as 500f.
 
I've read that the older Nicholson files were made with W1. I have no idea if this is true or not. W1 can have between (I think) 70 and 140 points of carbon. So you might not be getting a good austenizing temperature for the higher carbon steel or you might be tempering to high for the lower carbon steel.
 
Normally W1 is held to a closer tolerance than 1095. W1 C runs .9-1.0 normally. But like Bo said it might be W1 or 1095 or ?? depending on how old and what they were using at the time. Start low, 350f is where I normally start, then increase 25f until you get the results you want. Unfortunately you will have to do this with every file you use. You cannot be sure what the material is unless you get the same batch. Can't tell that unless you pull them out of the same factory box new. It takes some extra work to get the HT right on found steels.
 
thanks guys, i got the file from a shop selling old tools buried under a pile of other old rusty files...
will start low in the oven at 175c for 2 hours test and adjust.
 
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