Reamers

[Ed McDonnell]

When a reamer is specified as "o/u", what does that mean?

When reaming a hole out to increase diameter by 0.003", would a straight or spiral reamer be the better choice?

My google-fu just doesn't seem to be working tonight. I couldn't find the answers on my own. Anybody know (the answer or where to look)?

Thanks

Ed

 

[lorbay]

Over and Under.
In the sizes we use a straight is better.
Lin

 

[frank123]

A straight reamer is fine for most purposes, chucked or hand driven.

O or U usually -at least in my terminology knowledge- mean a specific size larger or smaller than the nominal size (useful for fitting press fit or slip fit to the designated size shaft). there should be a specific under or over size stated such as .0005 under or over.

There may be other designations that use o/u that I'm unaware of.

 

[Ed McDonnell]

Thanks.

Ed

 

[rherrell]

This is where I get mine...
Enco - Guaranteed Lowest Prices on Machinery, Measuring Tools, Cutting Tools and Shop Supplies

 

[Dalecamino]

This is where I get mine...
Enco - Guaranteed Lowest Prices on Machinery, Measuring Tools, Cutting Tools and Shop Supplies

Thanks Rick! I did a search a couple of years ago and, gave up. Been using my little crafting knife to shave the hole out. It works but, a reamer would be much better.

 

[plantman]

I use a tapered 5/8th reamer to clean and bevel the ends of my tubes. One size fits all on a tapered reamer. If you are wanting to ream out the entire length of a blank, you will need a straight reamer of the correct size. The o/u could mean two things, the tolerance that the reamer is machined to 5000th over or under the given size, or if it is an adjustable reamer, what range you can obtain from the stated size, over or under. Reamers also work well for rounding out a destressed tubes, or removing burrs from the end of cut tubes. Jim S

 

[Ed McDonnell]

Thanks for all the help. I'm making some solid metal pens and my adjustable reamers wouldn't go small enough for what I was doing. I had looked at the enco site and somehow managed not to find what I was looking for. Sometimes it pays to just page through the online catalog instead of using the search tool. Thanks for the link Rick.

Jim - I found a tolerance spec for DP reamers (+- 2 tenths). I never did find a tolerance spec for U/O (or U/S or O/S). I'm guessing that for my application a couple of tenths either way won't make a whole lot of difference. And if it does, that's what they make bigger hammers for.....right?


Ed

 

[ironman123]

Ed, in the online ENCO catalog reamer pages at the beginning of each manufacturer's listing, on the right is a rectangle with tolerances shown for O/U. Maybe you can use that info.

Ray