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Case hardning a couple of home made wrenchs

plothoundsman

Cast Iron
Joined
Mar 17, 2014
Location
BLACK MOUNTAIN NORTH CAROLINA USA
Well I would like to get some input , have a friend whom has made a couple of wrench's out of 1018 CRS , he called and asked me to case harden them . I have plenty of cast iron chips available, but surly do not want to pack my little heat treat oven full of messy chips , could I pack them & wrenches in foil ? also I am wondering about the quenching ?
We used to do this yrs ago ( 35 ) at a shop I worked at . Good lord it was yrs ago ! Just wondering your guys thoughts ?
 
The best thing is to have a thick cast iron box with a heavy lid,or a graphite crucible with a lid. We used a cast iron box we made out of a real large old hollow parallel with 3/8" thick walls. I left it there,unfortunately.

We use aquarium charcoal. It is full of tiny holes,to expose more carbon to the heat. Foil would just burst open if you tried to use it. It cannot take much internal pressure when it is hot.

I guess you could take a soft white firebrick and hollow it out carefully. Leave the walls good and thick. Use another solid firebrick for the lid,perhaps saw it to half thickness. Get the soft type,it will be easy to sculpt.
 
Thanks Ignator , that should do the trick ! It is not an aircraft spec. heat treating we are doing here , tho we do that kind parts, which require heat treating ( which I farm out ) to a very good source down in High Point. Thanks again
 
The only problem with using the Kasenit or Cherry Red products is that the case is very thin, producing a very hard wear resistant surface. For a wrench, one needs a high yield point through the body of the material, not just on the surface. I would expect the surface to crack if these wrenches are put to the test.

I have not used these products for deep hardening so I have no experience as to the depth of case with time. Their WEB sites do not appear to provide this information. For deep casing the manufacturers recommend different products.

Tom
 
Aquarium charcoal,or regular charcoal will produce a much deeper case than Kasenite(which is no longer available anyway),or Cherry Red.

Frankly,what you REALLY need is the wrenches to be made of a proper through hardening tool steel. You cannot make a casehardened wrench that will not soon fail. The surface may be hard,but the core will be soft and the jaws will soon spring open.
 
Aquarium charcoal,or regular charcoal will produce a much deeper case than Kasenite(which is no longer available anyway),or Cherry Red.

Frankly,what you REALLY need is the wrenches to be made of a proper through hardening tool steel. You cannot make a casehardened wrench that will not soon fail. The surface may be hard,but the core will be soft and the jaws will soon spring open.

Gwilson, can the aquarium charcoal be used in a similar way to kasenit ? Eg can a part be heated to red heat and merely dipped into a pile of charcoal or does it have to be packed in a box and heated in a kiln ?
 








 
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