I was wondering which type of steel rod to use as the uprights on the firebricks that are used to set the knife packets in while they are being heat treated? I was thinking of just using some cheap 1/4 inch steel from the local steel yard but I wanted to ask first before I bought some, as I didn't want it to melt while heat treatment of my blades was going on.

Your knife will melt before mild steel rods will. Increasing the carbon & alloy contents reduces the melting point for anything that we call "steel" as opposed to "cast iron."

You'll not be running anywere near that hot in a normal HT operation.

:)

No need to worry about melting, but, SS rods will hold up better WRT decarb.

I'm not a fan of the individual wrapped blades inserted upright between rods. I much prefer making a horizontal pack. this can be either a single blade, or multiple blades(all the same thickness). I lay the pack on a firebrick, which supports them 100% and provides great heat transfer into the steel. I cut two grooves in the support brick, which permits me to insert my "u" shaped shovel/spatula under the packet when it's time to take the packet to the quench plates. The advantage of this is that the "pizza man" technique is a lot less stressful than having to get a grip on the blades with tongs(I dropped a few in my earlier days!). Also, I don't like the idea of having to open the furnace door repeatedly when doing multiple blades. I have my blades out of the furnace in 5 seconds or less, and, they're between the plates 5 seconds after that!!!

Of course, this assumes you'll be press quenching, which is also my preferred method.

Try it, you might like it!