Heat Treat Oven Element Connections

[Fross]

Hello guys,

I have made a few knives I am proud of with a few K23 fire bricks and a propane torch for heat treat for family and friends. I am getting into some more complicated designs that I may put onto the market and don't trust the torch or my magnet and eyesight for this.

I have ordered and have everything in hand I need to build a 4.5" x 4" x 27" Inside dimensions heat treat oven running a ramp/soak controller and pulling 18 amps through 220v of electricity into my elements except a way to connect the elements to the power source. I am wondering what you guys that have made one of these before did with the kanthal a1 element connection to the high temp lead wire connection? I would like to keep the kanthal inside the oven, the high temp wire on the outside, I am having a hard time finding a local source for stainless steel threaded rod. What do you guys think, would modifying some 1/4" OD ss tubing into a type of wire crimp work, if not, what else...? Thanks.

Fross

 

[silver_pilate]

I ran to the nearest Sutherlands and bought the longest stainless steel carriage bolts I could find along with some matching nuts.

I drilled holes in the back of my oven to run the bolts through (the head of the bolt will be inside the oven). Just behind the bolt head, I ground a small flat in the thread and drilled a hole the diambeter of the kanthal. Run a nut up the bolt to the hole, and with the kanthal already layed in your oven, thread the end of the kanthal through the hole and tighten the nut up against it to hold it. Then run the bolt throught he hole in the oven, tighten down a washer and second nut on the outside of the oven to hold the bolt in place against the fire brick. For the outside connections, use a 6"+ length of high temp connecting wire, strip the end and secure it between two washers and nuts on the end of the bolt.

The connection between kanthal elements was done similarly with a stainless bolt and a larger hole to fit both element ends through with a nut tightened to them.

At first, I just used the old two washers and nuts trick to attach to the kanthal as well, but over time, the small gap between the washers and caused an arc which eventually burned through my kanthal. The drilled hole with the nut tightened to the wire eliminates this, and it's been running fine ever since.

--nathan