Welding Tips and Tricks

Hello.
My first post here. We need to extend some Power screw driver bits for a hard to reach application. Unfortunately we cannot just buy what we want. We have hunted high an low.


A couple different guys in the shop have taken a stab at welding them and they break in short order. I have no idea what they are made of but to quote Jody. They are harder than woodpecker lips.

My inclination is to try some 309 wire and a real slow cool down of the weld area to help keep it from getting so brittle.

Thanks

Rada

309 seems a logical choice as the exact alloy is unknown - but however good the weld is the strength of the bits come from their heat treatment which is destroyed as soon as you light up on it - so unless you have the facility or can find someone to re-heat treat them I don't see you having much luck - what is the bit type & length required - maybe someone here can find you what you need - a couple of regulars here love to find stuff on the web.

Rada,
I also believe 309 would be a good choice for filler material. If you re- heat treat them, you should be good to go.
Why not try a hex bit extention? If one is not long enough, use more. Some are quick change, like the harbor freight one and others are magnetic. I believe this is the easiest and more economical solution to your problem.

http://www.harborfreight.com/12-uick-ch ... 68516.html
http://www.ebay.com/bhp/hex-extension
http://www.mscdirect.com/product/066950 ... =-99&025=c

-Jonathan

I'm ignorant, I have heard Hasteloy W is the filler you need. Would the magnetic bit holders I use every day help? I use the short bits, with one or two of the 5" holders. Every power tool manufacturer markets them. They hold the bit with a magnet. You can slide the collar to prevent it from tilting.

Thanks for the replies guys.
Part of the problem is that we are using these in a production assembly situation. We are driving Stainless torx screws that we need to fish into some tough spots. We have found some drivers that are made to wedge into the torx head of the screw but they don't make them in long enough lengths. The welded bits fail right at the weld. I think the guys are just not doing a very good job of prepping and using the wrong filler.

We will get them fixed up. I think we can make it work with the 309...

I you are going to try to weld them here is a site and specs on how to weld tool steel. I am not sure what the bits are made of for sure, but this will get you close. I would say follow the "general considerations for welding tool steels" and let us know how this goes. My little experience with tool steel would recommend you heat part up to remove temper and do a full penetration weld followed by a VERY slow cool down. If you have sand or insulation that will work.
http://www.weldreality.com/toolsteelsS.htm
-Jonathan

I have an off-the-wall, non-weld solution...

That looks like a T-10, or at biggest, a T-15 in the picture, so you're working in the under 500 inch-pound range, I assume?

Press the bit (w/ a bit of epoxy) into a piece of 3/8" stainless tubing, with the wall thickness selected for an ID slightly smaller than the bit's hex dimension across the points, for a tight press fit, so the tubing must partially conform to the hex. Press a matching hex in the other end to fit the driver (also with epoxy). Voila', custom-length extension bits with no heat-stress issues.

Just a thought...

Steve S

Rada wrote:Thanks for the replies guys.
Part of the problem is that we are using these in a production assembly situation. We are driving Stainless torx screws that we need to fish into some tough spots. We have found some drivers that are made to wedge into the torx head of the screw but they don't make them in long enough lengths. The welded bits fail right at the weld. I think the guys are just not doing a very good job of prepping and using the wrong filler.

We will get them fixed up. I think we can make it work with the 309...

I can't find it, there is a you tube video the older thin man who does a titanium pipe video doing a tool alteration video. If I remember he talks about 312 stainless or Hasteloy W. I have an old maintainence welding handbook about the subject from Certanium. The down side is if you don't have access to Certanium products you can't tell what the filler is.

Otto Nobedder wrote:I have an off-the-wall, non-weld solution...

That looks like a T-10, or at biggest, a T-15 in the picture, so you're working in the under 500 inch-pound range, I assume?

Press the bit (w/ a bit of epoxy) into a piece of 3/8" stainless tubing, with the wall thickness selected for an ID slightly smaller than the bit's hex dimension across the points, for a tight press fit, so the tubing must partially conform to the hex. Press a matching hex in the other end to fit the driver (also with epoxy). Voila', custom-length extension bits with no heat-stress issues.

Just a thought...

Steve S

Going to give that a try.. Probably use Loctite 609 retaining compound.