Reamer Evaluation and Refurbishment

[EddyCurr]

I have come into possession of a collection of reamers. After
segregating a number that I felt were no longer suited for service
I happened to watch Tubal Cain's videos about reamers and observed
that several of his tools looked well beyond the condition of cutters
that I was prepared to discard.

Short of testing cutting action in a suitable hole, how do you evaluate
a reamer? Do you perform any operations to freshen used cutters (stoning?)
or just use them until they no longer function adequately?

It is my understanding that once a reamer is dull, it is discarded. Is this the
case or is there sufficient material on the flutes of reamers to regrind them
to the next smaller size (and is it economically viable to do so)?

.

[SGW]

FWIW, one of Guy Lautard's Machinist Bedside Readers, either #2 or #3, discusses reamers in great detail.

[sasquatch]

This is a good question Eddy,, i too have a few i picked up at a yard sale.

[bobw53]

As long as the major diameter isn't worn out, easy to resharpen.

They only cut on the end, so a quick zip on the belt sander, and you're good to go.

Easier than sharpening a drill that's for sure. If all your flutes aren't exact, oh well, too bad, they still seem to work pretty well.

Even if your OD is wrecked, re-size it on a lathe with a tool post grinder, sharpen the end, and now you are the proud owner of a mis labeled reamer.

[Rustybolt]

As long as the major diameter isn't worn out, easy to resharpen.

They only cut on the end, so a quick zip on the belt sander, and you're good to go.

Easier than sharpening a drill that's for sure. If all your flutes aren't exact, oh well, too bad, they still seem to work pretty well.

Even if your OD is wrecked, re-size it on a lathe with a tool post grinder, sharpen the end, and now you are the proud owner of a mis labeled reamer.

You're joking ,right?



Eddy
there are ways to touch up reamers and to sharpen them at home, but a sanding belt isn't one of them.

[TGTool]

In my experience the flutes on reamers rarely exhibit any wear. I look very carefully at the small corners that are the juncture of the flutes and the 45 degree flats on the end. If you can see a shiny rounded spot don't count on them to cut. They can be sharpened on a tool and cutter grinder or another machine where you can set up to regrind those little flats with some back relief like a four facet drill would have.

[bobw53]

You're joking ,right?



Eddy
there are ways to touch up reamers and to sharpen them at home, but a sanding belt isn't one of them.

I joke you not. Its a fricken reamer, the geometry is absolutely dead stupid simple, much simpler than a drill, and magnitudes simpler than an endmill. simpler than even the most basic grind on a piece of HSS for lathe work.

Yeah, hit it on the belt sander, not a 6 incher, one of the little guys, what are they 1x30? About $40 at HF. One of the most valuable shop tools, and for cheap.

I'm not doing this at home, though it is my hobby too, I make my living doing this, and yes... belt sander, its saved my ass many many times when I didn't have time to bring in a new reamer, or just didn't want to, and a lot of times I didn't have to order a new one thanks to the belt sander.

The belt sander also works like a charm on drills and putting radius's and odd features in HSS endmills. Also works great on HSS lathe bits.

[Rosco-P]

I joke you not. Its a fricken reamer, the geometry is absolutely dead stupid simple, much simpler than a drill, and magnitudes simpler than an endmill. simpler than even the most basic grind on a piece of HSS for lathe work.

Yeah, hit it on the belt sander, not a 6 incher, one of the little guys, what are they 1x30? About $40 at HF. One of the most valuable shop tools, and for cheap.

I'm not doing this at home, though it is my hobby too, I make my living doing this, and yes... belt sander, its saved my ass many many times when I didn't have time to bring in a new reamer, or just didn't want to, and a lot of times I didn't have to order a new one thanks to the belt sander.

The belt sander also works like a charm on drills and putting radius's and odd features in HSS endmills. Also works great on HSS lathe bits.

And was that a chucking reamer or a hand reamer you "touched up" on the belt sander? It still cut on size when you were done?

[gwilson]

He didn't reduce the diameter of the reamer by touching up the end of the reamer. Myself,I use a grinding wheel. It will leave a sharper edge than a belt will because there is no bagging with a wheel.

[Dan Dubeau]

And was that a chucking reamer or a hand reamer you "touched up" on the belt sander? It still cut on size when you were done?

I've done a few chucking reamers that way. It only cut's on the tip, and it's only the tip you need to "touch up". Usually just touch them up with a hand lap, or stone, but I've used the belt to completely redo a few that have been broken too.

I find a Loupe really helps out

For drill/reamers that are really messed up (I.e. broken tips) I use this method. Chuck them up in a drill, and run it backwards against the belt to get the proper tip angle, and put it on center, then I colour the tip up with a sharpie, remove from the chuck, and grind the relief on by hand. Took me longer to type it out. Learned that from a guy I work with who used to sharpen cutters for a living. Might not be every bodies way of doing it, but it gives me great results.

[J Tiers]

Chucking reamers cut on the end, yes, you "can" sharpen them that way. although I bet they cut a bit better if all the cutting edges are the same..... i.e. cut with some sort of solid fixture.

A "hand" reamer is a different animal, much longer slow taper, and take a different approach to sharpen right. Doable on any tool and cutter grinder, if you set the tooth support correctly, and the table angle.

Hand reamers might be more easily worn below size....

[oldtiffie]

As long as the major diameter isn't worn out, easy to resharpen.

They only cut on the end, so a quick zip on the belt sander, and you're good to go.

Easier than sharpening a drill that's for sure. If all your flutes aren't exact, oh well, too bad, they still seem to work pretty well.

Even if your OD is wrecked, re-size it on a lathe with a tool post grinder, sharpen the end, and now you are the proud owner of a mis labeled reamer.

"Machine" reamers are parallel and have that 45 deg cutting edge at the "front" and that is where most wear occurs and sharpening or reconditioning a machine reamer is quite feasible.

"Hand" reamers (non-machine ie driven by hand) are another matter as they are tapered. It is possible to "pick up" the taper and sharpen them on a good tool and cutter grinder.

If I have any doubts at all about any reamer I toss it straight out as there is nothing worse than a reamer that jambs or snaps in the hole.

[oldtiffie]

Oops.

Sorry JT.

I didn't see your almost identical post.

[smalltime]

And was that a chucking reamer or a hand reamer you "touched up" on the belt sander? It still cut on size when you were done?

NO.............

[Rosco-P]

"Machine" reamers are parallel and have that 45 deg cutting edge at the "front" and that is where most wear occurs and sharpening or reconditioning a machine reamer is quite feasible.

"Hand" reamers (non-machine ie driven by hand) are another matter as they are tapered. It is possible to "pick up" the taper and sharpen them on a good tool and cutter grinder.

If I have any doubts at all about any reamer I toss it straight out as there is nothing worse than a reamer that jambs or snaps in the hole.

Exactly, OldTiffie.
The OP doesn't state what kind of reamer he's using. In any case, a belt sander seems a coarse method of re-newing the cutting edge or a machine or chucking reamer and doesn't address any damage or wear along its length.