Teeth Material for Drum

I'm wondering what type of steel we (PV Engineering Club) should use for the teeth on the drum of our 120 lb. bot. I was planning on using S7 tool steel, but after talking to a couple welders I don't know how well it will work to weld S7 teeth, even if they weren't hardened, to the 1026 steel drum. Has anyone had success with doing this before? What type of steel could we use as a substitute that will weld, but can still hold an edge after impacts?
We could bolt the teeth to the drum (which is 11" OD, 10" ID), but there's only a little more than 3/16" of clearance between the drum and the motors inside the drum, so I don't think we could use nuts

Will welded heat treated S7 teeth to his steel drum and as far as I know he didnt have any problems

well that's a relief. Do you know how Will welded it? like arc welding or oxyacetylene? - just so I can tell the welder what works.

nope sorry
Maybe RJW will know a little more, maybe not

doesn't matter much what you weld in with, just use a median carbon steel filler rod. after you harden the s7 you need to bring it to 200 degrees fahrenheit and hold it there while welding it. you'll probable need a torch and a infrared pyrometer not to mention a patient welder. and make sure not to over heat the steel while welding it or you will screw up the temper and soften it. as long is you don't go over the critical temperature you can let it air cool, if you go over the critical temperature then you want to quench it in brine

Kyle (Koolaid64) seems to know what he's talking about!

Will has either a TIG or MIG setup at his house, and he did the welding himself I doubt he took all the precautions Kyle is talking about, but I wasn't there, so I cant say for sure. His drum ended up weighing 55 pounds, and hit Witch Doctor with one motor at full speed--the teeth stayed on. If I can get in touch with him, I will ask (we are on Spring Break right now).

Thanks for the advice Kyle. Is the process still the same if we're not heat treating the S7?

the whole point of preheating is to prevent a already hardened metal from becoming brittle after welding. sense your going to weld it in its tempered state there is no need for the preheat. but i would still recommend you us a median carbon steel filler rod