reamers

I went to an estate sale a couple of months ago looking for tools. I bought 2 vintage saws. When I went back to pick them up, the owner
volunteered to throw in some misc. other tools. I went home with heavy crates of various unsorted tools. Just now getting around to looking them over and sorting them out. Mostly junk machine tool parts. The guy must have been a machinist. Anyway, the box also contained about 20 taps by CARD and Greenfield, some very large sizes, and about 100 reamers. I don't know what the reamers are used for. I was going to toss them, but then I did some research on the web and found that they are quite expensive. They are all either Lavallee & Ide, National or Putnam. Some are in the boxes, some have some rust on the smooth part of the shafts, but sharp cutters. The question I have is EXACTLY what do you do with them. I am not a machinist but have always thought of buying a milling machine and lathe and learning as a hobby. Are these reamers something that a hobby machinist would likely use, or should I get rid of them. What is the quality of these brands.
Steve
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    Greetings and salutations....
On 18 Jan 2004 15:21:08 -0800, snipped-for-privacy@patmedia.net (sw) wrote:

    Bummer...sounds like a box of junk...tell you what...Pack it all back up, and, UPS it to me, and I will get it out of your way...     In a slightly more serious mode...yea...reamers are really useful. They are the tools that we use to make VERY precise, round holes in metal. You get the hole "roughly" right with a drill, then, ream it to size and shape.     Rule #1 - NEVER turn the reamer backwards (it breaks off the teeth and makes it useless).     Don't know about the brands...but, I suspect that if they are any good at all...they are liekly QUITE good. The "best" way to value them is to either search Ebay or simply sell them on Ebay. That is the new "street price" setter.     Regards     Dave Mundt
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snip---

You apparently have never honed a reamed hole. The typical reamed hole is scarcely qualified to be considered precise, let alone VERY precise. I'll agree that a well reamed hole is drastically improved over the typical drilled hole, however. Reamed holes are a distant second to properly bored holes and aren't even in the running when compared to honed bores. Reamers are notorious for generating multi-sided holes with bell mouthed conditions.
Harold
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    Greetings and Salutations...
On Sun, 18 Jan 2004 22:01:37 -0800, "Harold & Susan Vordos"

    This is true, I have not. my real experience is mostly in the area of cleaning up morse tapers in lathes, and, sizing mounting holes through (relatively) thin sheet.     However, I am always interested in learning more subtleties and tricks to make machining metal easier and better...and I suspected this thread would cause a few of those to come out from under the rocks.     More information is better than less!     Regards     Dave Mundt
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is
typical
It's difficult to have some folks understand that reamers are not reliable where precision is concerned. Many have been lead to believe that they are the ultimate tool for good finishes and tight tolererance and that simply is not the case. These are the same folks that would be most likely to argue the point endlessly, but have had no real world experiences to point out the weaknesses in reamed holes. It would be easy to draw that conclusion if all you had at your disposal was a drill press, at which time they would certainly be better than just drilling.
I've been in the shop since '57 and have seen results from the application of reamers that are to be admired, and results that would be better forgotten. When the right speed, feed and lubrication are combined with the proper amount of stock removed, I've seen holes that turned out quite well. As I stated, reamers are certainly an improvement over twist drills, but should be used with caution when it really matters. One of the very common problems of machine reamers is their ability to yield holes that are multisided. A reamed hole that has had a pin pushed through it a time or two, or has been lightly honed, will often display the pattern readily. While it is relatively minor, it is one of the things that can lead to part rejection when one works to tight tolerance. It is for that reason that I speak out. I readily admit that the problems of which I speak are rarely an issue for the vast majority of the work we all do.
Harold
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On Mon, 19 Jan 2004 14:54:40 -0800, "Harold & Susan Vordos"

    Yea...I see your point there. I know that I produced some interestingly faceted holes when I first tried using a reamer. It took a while to get a "touch" to cut smoothly and evenly.     Probably part of the "problem" is that I just don't work on the level of accuracy that would require honing a hole for accurate size and shape. (*smile*), perhaps if I was more heavily into pneumatics or hydraulics, I would have to learn the skills!     Still interesting to consider, though.     Regards     Dave Mundt
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But that is really the issue, isn't it? You must have frequently done work in which the hole was the *main* feature in the part. Those who frequent this group, and _many_ manufacturing industries do not have a need for holes which are required to be bored and perhaps honed.
Frequently, holes are used for fastening and location. Coming from a die making perspective, I would say that 90-99% of the holes produced by a toolmaker are used for these purposes. As such, although you're right, folks should understand that although there are applications for the holes you're talking about, most of us will never have such a need.
On that note, is there a reasonably visible industry that uses, what I would call, super finished holes? Perhaps for things like cylinders in engines and bearing producers? Any thing else?
Regards,
Robin
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is
typical
I thought boring and honing were fairly bad for leaving bell mouthed holes (although they're certainly round)? Not to say it's impossible to get a correct profile with a boring or honing tool, but they're not exactly perfect.
Regards,
Robin
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hole
There is no reason for a boring bar to leave a bell mouth in a hole. A hole that is bored with a sharp instrument and proper feed should yield a roundness in keeping with the bearings of the spindle. Cutting pressure should remain constant from one end to the other, thus should yield a bore that is round and parallel in all respects, assuming the cutting edge is not dull and dragging. Tool wear can be the one variable, but is generally not enough to effect a bore size unless one is boring particularly nasty material.
Honing is extremely precise, but in the hands of a fool it surely could leave a bell mouthed hole. My personal experience as a grinder and tool maker have proven to more than my satisfaction that honing is likely the most precise of all methods to achieve round, straight holes. I would place an internal grinder next. One of the projects I had to make was a set of 3/4" ring gages with a tolerance of only .000020". Holding the bores straight and round on a hone is absolutely no problem is you apply the tool properly, and it was the tool used to size the bores of the gages. They were inspected by a certified secondary standards lab and were within limits. By their very nature (by design), honing mandrels have a constant truing, or correcting action. A hole that is out of round and tapered is easily brought round and straight. Understand that the mandrels must be of the rigid variety. The spring loaded cylinder hones one uses for cleaning up a brake cylinder are virtually worthless, and yes, they do yield bellmouthed holes. They have no reason not to.
If in the process of your apprenticeship you have the opportunity to run any grinding and/or honing equipment, I think you'll quickly come to understand the things I've mentioned. Grinding and jib bore/grinding operating are the ultimate expression of precision work.
Harold
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As Dave says, very desirable tool to have for making holes on size. One note is not to throw them in a drawer and bang them into each other, They are hard and will damage each other. Roll them up in an oil cloth and keep them dry and no more rusting. lg no neat sig line

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reposting because it appears this got attached to another thread unintentionally.
I went to an estate sale a couple of months ago looking for tools. I bought 2 vintage saws. When I went back to pick them up, the owner volunteered to throw in some misc. other tools. I went home with heavy crates of various unsorted tools. Just now getting around to looking them over and sorting them out. Mostly junk machine tool parts. The guy must have been a machinist. Anyway, the box also contained about 20 taps by CARD and Greenfield, some very large sizes, and about 100 reamers. I don't know what the reamers are used for. I was going to toss them, but then I did some research on the web and found that they are quite expensive. They are all either Lavallee & Ide, National or Putnam. Some are in the boxes, some have some rust on the smooth part of the shafts, but sharp cutters. The question I have is EXACTLY what do you do with them. I am not a machinist but have always thought of buying a milling machine and lathe and learning as a hobby. Are these reamers something that a hobby machinist would likely use, or should I get rid of them. What is the quality of these brands.
Steve
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Hi Steve,
You may not know it yet, but you're a pretty lucky guy on this one :-)
The brands you mention are all good quality tools.
A reamer is used to finish cut a reasonably round, fairly accurately sized hole. In use, you drill the hole a few thou undersized (or to the nearest number,letter, or fractional drill size that is less than the desired finished hole size), then run a reamer through the hole at around 1/4 of the drilling speed with lots of lube. The reamer cleans up the hole wall and produces a finished size to pretty good accuracy. Run it fast and the hole is a bit loose, slow and it's a bit tight.
Reamers are finishing tools, they are not used to remove large amounts of material. They should never be turned backwards as this can chip the cutting edge, the cutting edge is not supported in reverse rotation. Spiral reamers can bridge a keyway, straight flute reamers will snag in one.
Chucking reamers (reamers with a round shank) should be used in a drill press at a minimum, not in a hand drill in any event. Reamers tend to follow the existing hole, so many folks recomment the use of a floating reamer holder rather than firmly gripping in a chuck. Holding the reamer in a lathe tailstock chuck would be an instance where the desire of the reamer to follow the hole versus the direction the reamer is pointed could cause bell mouthing or an oversized hole.
Some folks seem to think a reamer is the final word in generating round holes. It isn't, but it is better than a drilled hole in terms of size and much closer to round. Often good enough for bearing surfaces in low to medium quality requirements such as engine valve guides, shafts in low speed applications, and such. If you need a better than reamed hole, you bore and lap or grind to size, as any fluted cutting tool will generate some variation from a truly round shape.
In any event, if anyone ever "tossed in" a hundred L&I and similar reamers on a deal I'd be walking with wood (teak mind you, not just yellow pine) for a week!
Cheers, Stan
sw wrote:
<snip>
Anyway, the box also contained about

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Thanks to all for the insight. I thought that that was their purpose, but wasn't sure. Do you typically put them in a milling machine? I would suspect so, and if so, one without a milling machine would never have a use for them, true? A few of the reamers also have a square profile to the end of the shaft (the end that would go in the chuck). Why is this? Possibly for use in some type of hand wrench? Also, a few seem to be adjustable for diameter is this possible? Could they be used as milling machine cutters? i.e. to cut sideways sort of like a rotozip? I know these questions make me sound clueless, and typically I'm pretty knowledgeable about tools and building equipment, just not machining tools.
Steve

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Uh, oh.. Carpenter on the floor!
Sorry...
You don't have to use a milling machine. Only really important if you need your hole very perpendicular to the top/bottom of your work. You can do a reasonably good job on the drill press. I wouldn't go so far as to use a hand-held drill, however.
The square shank on some of those reamers means their "hand reamers" as opposed to "chucking reamers". You have to predrill to about .005" under the reamer's diameter to use them by hand. The main difference is the taper at the pointy end of the reamer. Hand reamers have a taper usually several diameters up. They are used with a tap wrench. Chucking reamers have a taper that's usually very small, perhaps 1/8" and less. They are used under power. Most people just chuck hand reamers anyway, but that's not really how they're supposed to be used....
The adjustable ones are just that. The size range should be listed on the shank, or at least a letter designation. You can look up what those letters mean as I believe they're standard. Those should also be used by hand, AFAIK. However, if you're not sure what it is, you probably can't use it.
As for using a reamer as a rotozip tool (or an "endmill" in metalworking terms), not really. Basically their flute geometry is wrong. They have insufficient chip clearance to be very useful (just to name one issue), and reamers don't have flutes which are parallel to the central axis of the reamer - they're always tapered one way or the other.
HTH.
Regards,
Robin
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Should have been, "they're". And I'm sure there are others.
(You know who you are)
Regards,
Robin
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