# Reamers?



## Janger (Mar 15, 2018)

Reamers - I'm looking for some imperial reamers - 1/4" to start. I found this accusize one on ebay

https://www.ebay.ca/itm/1-4-6-Flute...581118?hash=item259e6aacbe:g:fwAAAOSwxCxT0m9U

It's cheap and probably cheap. How many holes could I possibly expect to ream before it becomes worn out? I assume it's not useful after that as the diameter would shrink... I want to ream a lot of holes - about 140. I'd like it to work in the mill - not a hand reamer too many holes. Advice?

This set is metric: 
https://www.ebay.ca/itm/10pcs-HSS-H...463092?hash=item1a2ebfac34:g:M8QAAOSwHLNZTMh2 
cheap too. 

And the follow on question - where to get dowel pins? KBC seems pricey. Anybody local? If I buy an imperial reamer I need imperial pins, and vise versa...


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## PeterT (Mar 15, 2018)

My limited experience of reamers is exactly like drills & taps - the better cutting & lasting ones generally cost more. Sometimes you can get some less expensive Asian so-so's & sometimes they are complete garbage. Be aware that 'sets' might be a fixed x.000" over nominal. If that's what you generally want then fine. But when it comes to the subtle range like sliding fit, tight fit, interference fit, they you have to go to dimensioned reamers to suite like 0.1250 or 0.1255 and even those have a +/- tolerance. Places like KBC & Travers will show tables of the whole progressive range. So far I have only bought HSS, no carbide but generally I do mild steel & aluminum work.

Re dowel pins, the nice thing about KBC is they sell in 25 lots even though they show 100 qty. Many other places are min 100 qty. Just put 25 on the basket & it works out based on $/unit. Actually you can go smaller qty but they apply a small charge. Unless you are talking big diameter or length, they are quite cheap. So far I have only bought house brand, generally ok, the odd size looks bit better or worse for some reason. Or you can go next column over & pick Holokrome, more $ but good, consistent USA quality. Metric ones are not stocked in as extensive range, for that go to Ali (but longer wait). And lastly black oxide or silver ground. Its high quality hardened steel.


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## DPittman (Mar 16, 2018)

Janger said:


> Reamers - I'm looking for some imperial reamers - 1/4" to start. I found this accusize one on ebay
> 
> https://www.ebay.ca/itm/1-4-6-Flute...581118?hash=item259e6aacbe:g:fwAAAOSwxCxT0m9U
> 
> ...


I have a set of both of those reamers.  The imperial set I have in a set ( Accusize) of 29 in standard fractional sizes.  The metric ones are all shorter and not nearly as nice in the finish and ground.  
I'm happy with my reamers but I use them mostly on aluminum or brass and I really don't have experience with anything else in reamers.  I think I'm happy with the metric set only because they were so cheap.  I've hardly used them at all yet.

Don


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## Bofobo (Mar 17, 2018)

Reamers have 3 sizes, (1/4 ie; .249 .250 .251)  i have been watching several chucking reamer index sets on ebay, couple hundred per set shipped from ontario. no word on the quality yet but i do desire some myself


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## Janger (Mar 17, 2018)

Thanks guys. That helps. I bought just one Morse USA 0.250 spiral reamer from quest industrial. $29.35. Also some 1/4 dowel pins. $0.33 each. They’re open sat morning BTW.

Did a couple test holes - the 0.25 reamer makes holes that measure to 0.2505 according to the mititoyo. The pins go in tight. I can partly push the pin in by hand but I can’t pull it out with my fingers. Should be good for permanent assembly. My application though is a little different. I’d like the pins to be non wiggly but removable with my fingers. It is for a vise jaw with pins to allow for different angle setups. I suppose a reamer diameter 0.251 would be better for this.

Morse taper http://www.morsecuttingtools.com/cg...PAHDID=000000185473774&PARDID=893834233700220

@Bofobo @DPittman Mike & Don do those sets you guys are looking at or have have sizes like 0.250 0.251 or is it 1/4 15/64 fractional sizes?


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## Bofobo (Mar 17, 2018)

Yes to remove the dowel by hand use an "over sized", "under sized" is for press fit.


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## RobinHood (Mar 17, 2018)

As has been mentioned, here is what you probably need; these ones came in a set, did not buy them individually.



 


 




But since you already have a 0.2500 reamer and 1/4” dowel pins that are a little snug, why not lap the pins to get the fit you desire?


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## Janger (Mar 17, 2018)

Thanks Robin lapping is a good idea. I wonder if the sets are like tap and die sets. It seems like quite a few sizes I’ve never used. 

Gotta love this forum -  all the members contribute and pay it forward.


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## RobinHood (Mar 17, 2018)

John, to be honest I am not sure; i got this set as part of a big tool sale. It is DoAll sold by DoAll Western Canada LTD from Edmonton. The part number is 712 DoAll 085968. Not sure if they still exist....

True about the sizes. They cover 1/8, 3/16, 1/4, 5/16, 3/8, 7/16 and 1/2 nominal size (for which i have standard reamers). Since there is one each of 0.001 under and one each of 0.001 over the nominal size, we get the not so familiar sized reamers.

Cheers, Rudy


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## PeterT (Mar 17, 2018)

If its an application where you need a certain tight-ish fit, but the pins need to come in & out more frequently & you cant get a good external grip, consider threaded dowel pins. Rig up a simple puller extractor stud that engages the threads. KBC has them, but they start at 0.250" diameter.

You can lap the fit for sure, just be aware of which 2 will change dimensions a result. If you want relatively interchangeable pins (and they are guaranteed to be to a certain tolerance) then the hole must be lapped. If the hole diameter is sacred, then the pin needs lapping. Dowel pins are quite hard so if you simply put some paste in between it & a hole in say mild steel, likely the hole will enlarge. In this mode the grit is basically rolling. That's a perfectly valid method if its OK for your application. To do a I guess 'proper' hole lap, you ideally should make or have a male lapping tool, like brass, copper, aluminum... something softer (or harder but has open porosity) that imbeds the grit into the tool. Think of it as like what grit is to sandpaper. Blind holes can be a bugger for this reason.


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## Janger (Mar 17, 2018)

What I was trying to get at with the set approach was the unused parts in the set. I’ve found with my drills, tap die sets is some sizes get used and even need replacing and some sizes are still new in the case. So why did I buy a set? Just wondering if I buy a nice reamer set if this will also happen. Not the end of the world of course...


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## RobinHood (Mar 17, 2018)

Agreed. I have so much tooling that is part of a set that will probably never get used. I typically do not buy in sets for one-of work...
So much of my stuff has come from sales/auctions that it was either all or nothing....


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## johnnielsen (Mar 17, 2018)

It would be a good idea to touch up the reamer occasionally with a very fine slip stone (not on the diameter but on the flat of the flute cutting edge).
Interestingly, I was reading that toolmakers will run a hardened pin up the flute to cause a miniscule burr to cause the reamer to cut ever so slightly larger.

In the future, depending on how much you want the reamer to remove, you could make a couple of straight (no helix) reamers from .250 dia. O1 or W1 drill rod.


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## Alexander (Mar 18, 2018)

Busybee has reamers up to 3/4" I bought a few there and they work good. In any shop I have worked in we just throw the reamer out when it gets dull. HSS reamers are the norm can't think of a time i used a carbide reamer. The spiral flute reamers are only required if you are going to ream out a hole that already has a keyway cut in it. The straight flute reamers will be just as good on a regular hole. Often I just use coolant as lube because it is not possible to manually add cutting oil while the part is in the CNC machine. The doors will be locked and im probably busy deburing the previous part anyways.


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## buckbrush (Apr 11, 2018)

I do this with a 1/4" H.S.S. tool bit. You can also make it cut smaller by running it on top of the cutting edge.


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