Can you ID these lathe tools?

Taper reamers. Home made. The model locomotive builders use similar for making working model injectors for topping up their boilers. Cheap and easy to make, without having to use any high tech measuring tools, as you start with a diameter, and a distance, then grind or machine away half, harden, then stone the face.

Carbide isn't just for hard materials. It is also used for abrasive materials (some plastics, some woods, fiberglass, etc.) as well as to enable the use of the higher cutting speeds allowed by the carbide.

I've seen similar as blanks for boring tools, as well as as single edged engraving cutters. The engraving cutters were usually round shanked, but they had the profile ground to a half round shape for most of their length. The were sharpened by taking a single compound angle grind across the end.

If the grind goes full half round, or just quarter round, they may be pre-ground blanks for boring or internal threading tools. With a square shank on them, that's what I'd bet.

I've lost money betting, before, though.

Cheers Trev

Add these to trevors' responses,

I've seen similar cutters used to trepan rubber, and in with tramels to cut gaskets, I think the points might be to blunt but engraving is done with similar tools also.

I first thought this was a boring bit by the angle of the top rake, but the second picture shows side rake (not normally used for brazed boring bits). I have seen similar brazed bits on old large face milling cutters.

I can't see the back side, but if the tool is ground 1/4 around with a flat top and a flat back with about 5-7 degrees front clearance it would be used to trepan face grooves with a lathe (and by the length of the business end the user would have much bigger stones than I do).

Matt

That looks like a D-bit engraving cutter, made mostly for use in pantograph mills. They were very common before CNC came along. I have a few of them that came along with a box of miscellaneous tools. I've never found a use for them.

There are many kinds of D-bit tools; this is just one type. I see that Trevor suspects they're tapered D-bit reamers. It's possible, but considering how common these tools once were (look up "D-bit grinder" on Google), I think it's more likely they're cutters for a pantograph. They looked the same as tapered reamers.

Ordinary carbide-tipped lathe bits.

I suspect the first and last are single-lip reamers, but I'd have to see it. The second is just a repeat of one of your lathe bits.

-- Ed Huntress

Whups. End view, It would take a real pair to plunge with this one.

That one's got me. The lip looks like a reamer, but single-lip reamers need a bearing surface opposite the cutting edge, like a gundrill. I can't figure that one out.

-- Ed Huntress

Face groove or trepan, too long just to groove, so I suspect trepan

(snip)

Yup, it's a trepan, I've used them but "never" to work at that depth. Manchester makes curved support blades for inserted tooling, I don't know if Iscar does or not.

Most often trepanning is done for a support/location lip or face seal using "O" rings.

Used to be you could get tool steel trepanned, die blank with a hole in it, they kept the inside, you got the blank with a large starter hole, for the same price as the solid plate. Expensive material saved, labor saved, win-win.... Who said "GREEN" was a new thing.

Matt

I don't get it. How do you trepan with a solid tool? Or am I misreading the photo, and this thing is hollow?

For that matter, how would you face groove with this tool?

-- Ed Huntress

Oh, I think I see what you're saying. You're talking about holding the tool in the cross slide of a lathe and trepanning a hole with a single point cutter.

But that still doesn't make sense to me. This tool appears to have a long cutting edge. A plunge-type face cutting tool only cuts on the leading edge, and it would need relief behind it. What's all that cutting edge for, if it's a tool for face-cutting disks on a lathe?

Are we talking about the same thing?

-- Ed Huntress

I considered that they may be pantograph bits, and discounted it on the tip shape, as all the ones I have, have been lopped off at a diagonal, in order to form a single cutting edge on the end.

I suppose they could be, though.

Any back-story onthe tools that they were together with? That may help explain. Or not. :)

Cheers Trev

You got it Ed, long parting was often done on turret lathes with neutral rake tools so the cutter wouldn't self feed. The blade is a bit above center with a bit more clearance and the little nub at the center just breaks off.

Lathe trepanning is worse, the tool (again above center) is ground with a slight angle on the end to "push" the back side against the ID, or is ground square (height on center) and the cuts are "pecked" by hand feeding.

The front clearance determines feed rate and is important, and if you see chips breaking pretty soon there may be a "BOOM".

It is a quick way to make an 8" hole in a 12" plate, and of coarse saves a 7" blank...

Matt

No, just present in 30 Lbs of various lathe cutting tools. They came from an old race car machinist. We still fool around with magnesium suspension castings and wheels. I have a nice set of Val-cut trepanning tools, works nice but cutters are expensive.