MT2 shank x 3/4" end mill looking for good home

[JRouche]

Like so: https://www.alvordpolk.com/special-t...-style-reamers

Straight shank reamer is what I see. JR

[JRouche]

Jig Borer Reamer and click the images tab and tell me what you see.
This is a Pratt & Whitney set in the box.
Or do the same on ebay.

-D

That Sir is a beautiful set. No doubt the reamers and end mills all come in MT right? The original pic for the freebie looks like either one, as I already said, it looks like a reamer just as Doz said. Can I have that set please

Point is they did produce end mills in a MT shank. I dont have any. JR

[reggie_obe]

Straight shank reamer is what I see. JR

Good eyes.
It's the cutting portion of the tool and what its called by the tooling manufacturer that count.

[JRouche]

Good eyes.
It's the cutting portion of the tool and what its called by the tooling manufacturer that count.

Spot on Reggie. I agree. JR

[BCRider]

Any part numbers on that cutter?

No, there wasn't. Just "Butterfield Canada", the 3/4in size and the city in Quebec where it was made.

Doozer, I don't doubt that this style cutter was used by jig borers. But a whole company doesn't list them in their catalog as "End Mills" if they were actually intended solely for use in a jig borer as a reamer. You can jump up and down as much as you want but that doesn't make you totally right.

[Richard P Wilson]

As far as I can see, the main difference between an end mill and a jig bore reamer is in the end. Ignoring centtre cutting endmlls, a 'standard' endmill usually has a small centre drilling, like a centredrill would produce, and the end teeth, at least when new, are ground slightly concave so they produce a flat surface without any tendency to 'drag' when traversed over a workpiece.

A jig bore reamer on the other hand seems to have a largish counterbore in the end, and the teeth are ground flat, so can't be used to mill a surface flat if you want good results, unless your mill is perfectly trammed.

The other difference seems to be that jig bore reamers when new are eye wateringly expensive compared to the equivalent end mill.

I find it amusing (OK, I know, tiny minds are easily amused) that Doozer will not accept catalogue descriptions from reputable US tool makers that what they are selling are endmills, but expects us to believe, because of a hand written label by an unknown Ebay vendor, that what he has in his lovely wooden box are jigbore reamers.

They might well be, but until he shows us the ends of his tools, we won't be certain, will we?

[Willy]

MT Patter Spiral End Mill SPE-MT (SKH51) (SPE-MT10-MT2)

[Doozer]

It seems to me that since jig boring fell out of favor with the cnc revolution,
that a whole generation of people forgot what jig borer reamers are for,
and in their generational ignorance, they call them end mills, because they
don't know any better. If they don't know what a jig borer is, they sure as
heII don't know what a jig bore reamer is. How many of you here don't have
a clue what a jig borer machine is ? ? ?

-D

[Richard P Wilson]

OK, now I'm even more confused. So how do you clever chaps tell the difference between an end mill and a jig bore reamer? Do tell - I'm all agog.

[Doozer]

OK, now I'm even more confused. So how do you clever chaps tell the difference between an end mill and a jig bore reamer? Do tell - I'm all agog.

Read my first post # 3.

-D

[Richard P Wilson]

No. Haven't we shown you enough catalogue pictures showing endmills with MT shanks to prove that what you said isn't right?

So I'll ask it again, how do you tell the difference between an endmill and a jig bore reamer?

[Willy]

I think Doozer has made a very good point, in spite of what the catalogs show, without a drawbar to retain it how could it be expected to deal with side loads within an MT2 taper.

[J Tiers]

Both B&S and MT are classified as self-holding tapers. I'd concur with that, given how I used to have to pound the MT loose in the mill, and the wedges needed to loosen it in the drill press. The MT2 and MT3 are normally stuck tight.

Nobody would expect an R8 collet or tool to hold at all well That wide open large angle taper is unsuitable for it. The MT is within the self-holding range, but not by as much as the B&S. The B&S is probably somewhat better. It is 0.5" per foot as opposed to around 0.6 to 0.625 as the various Morse.

The nature of the end mill is to generate some vibration as the teeth sequentially bite into the metal of the work. Vibration does loosen up even self-holding tapers. Whether the MT is an "Oh, yeah, that will fall right out" as some claim, or whether it still takes a good bit of effort depends partly on how the taper was inserted, but mostly on the actual taper. The closer to straight, the less loosening.

I'm going to find out, if BC sends me the tool. This entire question is one that has puzzled me for a while. When I first saw a pic of an end mill with the tang and a morse taper, I thought it was very strange.

But, I doubt if anyone would have continued to make these things if they were an instant and obvious "fail". Given that they are all called "end mills" in the places I have seen them, and that jig bores are a lot less common than milling machines, there has to be something behind it. Clearly they worked as end mills.

I suspect that the answer is in two places:

1) the usage, as in probably not used to hog off in deep cuts.... Horizontal mills would have been both more effective for deep slots, and easily available in nearly any factory.

2) The typical "fail" cited is the person with no mill attempting to use their drill press as a mill (complete with wallered out or inaccurate MT socket, loose quill, and long stickout due to using the drill chuck to hold the end mill). That often is a quick fail, but the quill slop, vibration, etc, is pretty much calculated to loosen anything, including your teeth as you try to use the bouncing and jumping thing to cut accurately. The optimistic user may also try to use too much DOC, which would not help at all either.

We'll maybe see. I'll give it as fair a test as I can. I have an MT2 and an MT3 mill available. If it is a B&S taper, well, that will be a complication. I have an adapter for B&S to MT, but not the reverse. I'll have to make something, then, and that may affect the results as well as the timing of the test (takes longer).

[old mart]

Having seen the brochure that JR posted in # 17, I have to admit that it is a milling cutter not likely a reamer.

[BCRider]

It seems to me that since jig boring fell out of favor with the cnc revolution,
that a whole generation of people forgot what jig borer reamers are for,
and in their generational ignorance, they call them end mills, because they
don't know any better. If they don't know what a jig borer is, they sure as
heII don't know what a jig bore reamer is. How many of you here don't have
a clue what a jig borer machine is ? ? ?

-D

I'm pretty sure that the earlier tool catalog reference was from the "Golden Age of Jig Borers". It was suggested that it was an older dated catalog after all.

And it's not like jig borers have moved to the same vintage status as planers either.