Hi guys,

Well as I made great progress in 2 weeks by building a solid table and gantry on my first build, I thought I would install my bearings and rods and test the water. Not so good. I chose linear ball bearings and it appears that my choice of oil hardened drill rod (the cheaper stuff) is intantly scored by the bearings. Can anyone confirm my error and suggest what Rockwell the rods need to be to survive?
Otherwise all is going nicely. Should I post pictures? Here they are. I hope this is kosher to do so here.

Thanks,
Ken

I don't know the Rockwell ( I think around 60 though), but you need precision ground hardened shaft. You can get it at Mcmaster-Carr or MSC. You'll find it in the same section as the bearings.

It needs to be 60 to 65 rockwell, Are they inch or metric?If metric you can also buy them from vxb.com

Thanks Guys,
I'm using 3/4. McMaster part# 8888K95 is what I'm now looking at Rockwell C 62-65. Precision Ground $44.54 per 36"
Sound right this time?

Hello, you could also use C-60 shafting, also known as thomson shafting 60-rockwell. Pat

McMaster-Carr part# 8888K95 is A2 tool steel and is supplied annealed at Rockwell B85-B103. Notice the listing says it can be heat-treated to C62-C65. The heading says Air-Hardened meaning you can air-harden it. (oh poop :) ) . You could get it heat-treated and polish it but I doubt it would be straight. You need part #6061K64 $36.31 for a 36 inch pc. Hmmm cheaper and harder.

I got my shafting from http://www.qbcbearings.com/RFQ/Default.asp?Page=B612Main.htm

Their shipping estimator was off but their shipping rates were still low when I ordered my 2 60" and 2 24" lengths of rod.. Their prices were lower then anyone else I've seen but maybe some have found better..

Thompson quick shafts...

b.

Thanks everybody, I would have blown it again without you. McMaster is wonderful. They try to go out of their way to keep bumpkins like me from messing up. I think I must have absent when science class covered metallurgy.
Thanks foe the stock number CarbideBob, case hardened surface sounds good to me.

Ken

ps- can anyone tell me why my thread title is not bold like mos of the others? Newbie status showing?