Repairing an insert tool holder.

Since I am probably the first One to ever trash a carbide insert cut off holder , I was wondering what to weld it back up with.

Garbage can

Green rectangular pieces of paper do wonders.

I have been known to weld em back up, difficulty is reshaping the insert seat well enough and accurately enough to be stable on a typical self gripping parting tool, IMHO your far better to buy another holder in all but emergency situations. For parting tools, IMHO not having a spare blade or if its a one piece holder available your just asking for issues.

From Chinese sources on the bay you can buy new good std turning tool holders for sub £20, i frequently buy boring bars for under £5 a holder and the bad bit is just how good they are compared to the same holders being sold for north of £50 by the likes of MSC!! All the ones i have bought have been great quality wise, nicely hardened but not brittle, insert pockets very accurately machined and what can only be rated as a truly first class blackened high gloss finish. The double ended insert style chinese parting holders and there middle of the road inserts work really well for me, over here a holder and 10 inserts in that style will set you back north of £100 same performing tooling from china direct and you can have change for £30! Don't by dirt cheap Chinese inserts, there generally crap, but buy the ones costing approximately 1/5th the list price of a box of 10 and you seam to get very good value for money and a very usable - good performing quality level.

Personally i love it when there dumping practises makes it easier for me to compete with them!

Get a job with CTS and then you'll know
http://carbidetool.com/home/
Most holder are an alloy steel, 4140 or such. When they repair, they weld, anneal, machine, heat treat, and then oxide if required.
JR

mark costello said:

Since I am probably the first One to ever trash a carbide insert cut off holder , I was wondering what to weld it back up with.

Click to expand...

If you are enough adventurous use TIG and small HSS drills as filler metal.
Been there, done that.

MGMN-style parting/grooving tools are easy as you can just cut the insert pocket deeper(no critical dimensions on rear part of the insert) and shorten the knackered part.

MattiJ said:

If you are enough adventurous use TIG and small HSS drills as filler metal.
Been there, done that.

MGMN-style parting/grooving tools are easy as you can just cut the insert pocket deeper(no critical dimensions on rear part of the insert) and shorten the knackered part.

Click to expand...

Mattij, Now You went and said it. Now I've got a challenge. Just have to try it.

JRIowa said:

Most holder are an alloy steel, 4140 or such. When they repair, they weld, anneal, machine, heat treat, and then oxide if required.
JR

Click to expand...

Or weld, machine, oxide.
Outside of some very special and very high dollar stuff I don't know any holder repair shop that anneals and heat treats repairs. I know some talk this as a sales pitch........
Problem here being the inevitable distortion of these two steps means re-machining all surfaces on the tool which means a lot of welding so you have stock to bring it all back in. At this point it is cheaper to make a new tool in most cases.

Correct that most holders are 4140 (or some 6150, H17) and in the 40s. Somewhat standard rods for these steels will go on in this hardness range.
Milling cutters are usually softer than lathe holders since the pockets have to be finish machined after heat treat. (on a lathe holder or cartridge you can mill/grind the shank to bring in the F/H/L dims leaving the pocket untouched). Some cut-off holders are down in the 30s and never see a heat treat process.

Sometimes you have holders that just need to be in the 50s and here you use a rod that is a bit of a mismatch chemical wise but goes on up in this hardness range. Obviously these are harder to machine and match due to deflection of the small endmills you are working with.

It's the re-machining and blending within tenths to the old steel that is the art. The other art side is to not lay on any more weld than is needed.
Normally a cold or mid temp black is used unless the volume is very high. (which brings the question of all the new shiny nickle plated stuff)

On the weld side, everyone I know in this racket uses TIG welding but one could get away with MIG and some standard (soft) wire if the machining is done right and the damage is just a tip.

A done right repaired toolholder should produce 100% of the life a new holder, no questions asked.

Not sure the holder or damage.
Bench grind away any welded on material. (very important step to get to base metal)
Tig up with 4140 rod, recut the pocket. Easy-peasy and in your sleep once you have done a few hundred.
The first few, not so easy and things go sideways (pinholes, seams) but it that may still work just fine for you.
All else fails you just pour a whole bunch of heat in and weld the end way big and solid, but you have to know how to recut the pocket out of this big blob of metal.
Bob