Box for deep pack case hardening

[rich pierce]

I’d like to see what sort of box folks are using for deep pack case hardening.  I’m thinking 7” long by 3” wide by 2” tall made of 1/8” steel with a coffin lid, a long rebar “handle” welded on and a loop atop the lid. I’ll use it for trigger parts and lock parts.

[44-henry]

These are some I have made for the purpose. The real tall ones are more commonly used for charcoal bluing, but the can be used for color case hardening as well. I make mine from mild steel pipe and weld caps on one end. The other sits on a steel carrier in an inverted position. My quench tank  is a 55 gallon steel drum which has a sheet steel cover with an opening in the center. When I quench I move the whole crucible and carrier to the tank and slide it over the hole, the carrier is stopped ba a small sheet metal spacer that I welded to the top, so only the crucible can slide over the opening. This results in zero air exposure and a controlled quench.
 

[rich pierce]

I like it. Thanks!

[Rwnblack]

Here is one I made to caseharden my woodsrunner lock last week.

[rich pierce]

Beautiful result!

[Goo]

I case hardened a knife blade it was my first time trying to do this, I used some stainless steel foil.  My goal needed me to allow the piece to cool down slowly when I went to unwrap it the stainless foil had absorbed a lot of carbon and was extremely brittle, which begs the question how long do these steel boxes last before the crumble?   I`ve been giving this some thought and am wondering if a ceramic container would be more appropriate if quenching is not needed.    I am also thinking a long pipe nipple threaded on each end would work.     

[flatsguide]

Nice looking lock. What finish was on the plate and cock before case hardening?
Cheers Richard

[44-henry]

My mild steel crucibles deteriorate pretty rapidly at carburizing temperatures. I can run perhaps 10 cycles before they come apart. Stainless lasts longer.

I case hardened a knife blade it was my first time trying to do this, I used some stainless steel foil.  My goal needed me to allow the piece to cool down slowly when I went to unwrap it the stainless foil had absorbed a lot of carbon and was extremely brittle, which begs the question how long do these steel boxes last before the crumble?   I`ve been giving this some thought and am wondering if a ceramic container would be more appropriate if quenching is not needed.    I am also thinking a long pipe nipple threaded on each end would work.   

[Jim Kibler]

We just use steel pipe / tubing with an end welded shut and a lid.  Not sure the difference, but ours have lasted quite a long time.

[Rwnblack]

Nice looking lock. What finish was on the plate and cock before case hardening?
Cheers Richard

I polished it to 400 grit.  It isn’t super fancy but I like it.

[kutter]

When I worked for Turnbull, we used Trapezoid shaped containers , when viewed from the end.
This pic is upside down for some reason, but you get the idea.


Ours were a bit less angled so the base was larger and the sides not as acute an angle.

Made from 1/4" plate low carbon steel welded up. They had a 1/2 'lip' all the way around at the top.
On that the cover sat which was just another steel cap with folded over sides .
The lid had to sit squarely on the box. but it was otherwise not fastened down in anyway.

The box had a steel pipe welded on each side for a 'fork' to be able to be inserted to lift the box into and out of the oven. The latter for quenching, the box with lid removed was set on a support for the fork handle and then just rotated 180* over the top of the quench tank to drop the parts.

The parts were individually wired in place to the box with 'aircraft wire' (Stainless) so they dropped into the quench but did not quite hit the bottom of the tank. This accomplished as the parts were being packed into place.
The wires were looped at the free end and passed thru a pull-pin that went lengthwise thru the entire bottom length of the box.
Once the parts dropped into the quench, a few seconds count was done and then the pin was pulled and the parts released  and fell free of the box and the rest of the way into the bottom of the quench tank and into the spent char-mix in the bottom.
No aggitation of the quench water, no added chemicles. Water heated to 90F.

Boxes got used about 25 times and then discarded.