diggin in my stuff (what that?)

[davidh]

today i was doing a bit of organizing (kinda) and ran across a couple 3/4" armstrong carbide lathe tools. can a guy just grind down the 3/4" steel and use these guys in a smaller holder or is there a problem with the carbides being too large ? and what is the tool on the left used for? actually i found about 4 of those. . . .

[Uncle O]

I believe that is a facing tool

[wierdscience]

You can grind/mill down the shanks pretty much however you want,so long as you don't mill them down too thin where they bend of course.

[Machinist-Guide]

Tool on left

This tool can be used for turning. Mount it on the back side of your tool post parallel with the lathe bed

[sconisbee]

Tool on the left is a left hand turning and facing tool, the brazed insert equivalent of something like the SCLCL or PCLNL type insert holders


I wouldn't worry about making the shanks smaller they might not even be hardened

[gzig5]

The shanks on these brazed carbide tools is mild steel of some sort. Actually mills pretty well. I just milled a 3/4" square shank down to 1/2 and it cut like butter.

[DR]

Not a problem with too large carbide.

The problem will be no (or very little) top rake. Plus, no chip breaker.

[AiR_GuNNeR]

Not a problem with too large carbide.

The problem will be no (or very little) top rake. Plus, no chip breaker.

When you cut/grind it down to size, can you simply do it at an angle to get your top rake?

[dp]

Clear evidence that you need a shaper!

[davidh]

i did mill two of them down last night on my bridgeport using a carbide tipped single point tool in a cheapo flycutter. bang bang bang bang, every revolution. it did work, i needed to sharpen the carbide once but it still worked. maybe i should have used a ruffing endmill ? i have no clue. but i still have more to do.

why would i need to change the relief of the carbide ? i am just re-sizing the square of the tool.

these are painted grey, im guessing someone took them from the military a long time ago. they do say armstrong on them however.

on another note, i found a 1/2" "cobalt" stick cutting tool in the mess. nice and shiney. in researching cobalt, i read that its not solid cobalt but a small % added to the hss to make it a bit harder. is this true ? i have a good set of cobalt drills for removing broken allen head screws and stuff and they seem quite a bit better than just good drills. is there an advantage to the cobalt additive in lathe tools ?

davidh (the guy with many questions)

[recoilless]

I've milled down some 1" shanks I picked up at an auction no problem. I seem to recall someone else actually milling a female dovetail into some of these to use on a QC toolpost. Maybe someone saved the thread here.

[davidh]

geeeze why didn't i think of that. . good practice on the dovetails.

[Alistair Hosie]

I've reduced these type of shanks often,but you must do a file test first.I never came across one yet that didn't turn out nice.I wish you well I have spent alot of money buying a nice set of kennametal tools which I am going to convert to using from now on along with the tools I have both with hss tools and those with carbide cutters soldered on may become redundant.Keep happy and well .Alistair