Is it abuse if I………..?

[Bill RuleParticipant @billrule36498]

Having no experience/instruction, I’m unsure of a few things..

[Bill RuleParticipant @billrule36498]

Hi all.

Generally, I can get on with the job in hand, working out what I need to from first principles or trial and error, but some things give me pause. Specifically, the tap wrench looks perfect to useon a hand-reamer; but there must be a point that the torque exceeds what is healthy for the wrench. I feel that a 5/8 reamer would require a lot more power than a 5/8 tap, or am I worrying over nothing

[Steve GarnettParticipant @stevegarnett62550]

You haven’t said how hefty the tap wrench is. The only one I have that would fit over the square on the end of a 5/8″ reamer is hefty enough that I think I’d run out of torque before anything happened to it! Also, of course, it rather depends on what you are trying to remove with the reamer. If this is just a final fine cut, then the force necessary could easily be well be less than that required for a full-length bottoming tap, I’d say.

 

I think that most people just ‘feel’ their way through these little difficulties, don’t they? If you feel the wrench handles starting to bend, then put a spanner on the reamer – or find out why it’s got so stiff!

[Ian S CParticipant @iansc]

It should not take too much to turn the reamer if you use the lubricant suitable for the material , and don’t try taking too much of, just a few thou. A hand reamer has a taper at the front end, enter that and as you turn the reamer slowly feed it in. If the reamer fits in the tap wrench, the wrench is proberbly big enough (it might be bigger than required), I’d say about a foot long/6″ handels would be about right. Ian S C

[mgjParticipant @mgj]

To amplify Ians point. How much to take off with a reamer – couple of thou tops, so a reaming load should be very low.

 

I’ve seen it sometimes recommended that one can drill to say 1/64 (.015) undersize and then ream, but that frequently resutls in an unround hole. If one doesn’t want to bore ot the reaming size then a metric drill will often provide the answer.

 

A reamer shouldn’t really do more than just wipe the hole to size, and as a result a tapping load should be much higher. Of course, many charts are notorious for specifying tapping dias which give 90% plus engagement, which is a good way of causing jam ups, so getting the tapping dia right reduces the load considerably too.

 

 

[Steve GarnettParticipant @stevegarnett62550]

Posted by Ian S C on 01/06/2011 14:57:05:

If the reamer fits in the tap wrench, the wrench is proberbly big enough (it might be bigger than required), I’d say about a foot long/6″ handels would be about right.

That’s about the size of the one I had in mind, and I think you’d have to put in a significant amount of effort into those 6″ handles (or an extension pole) before you’d have any significant chance of bending them. I’ve used my large one (very similar dimensions) on hand reamers before, and never felt that it was in any significant danger of damage – but there again, I wasn’t trying to ream out a much larger diameter, and it wasn’t a particularly long hole… but they don’t have hardened handles, so they aren’t likely to snap – which may be what William is worried about?

[PatParticipant @pat]

William – Some where along the line we have all broken both taps and reamers. Just get used to the nasty feel of the handles moving the reamer / tap shank giving but the business end staying still. The feel is one of a springy action which is easy to detect as being different from the normal cutting and indicates a jam is about to turn into a major task of removing the broken bit from the work piece. Back off remove and chips apply more lubricant and start over. Good practice is to reverse for a 1/4 turn every turn untill you know better for the material in use.

 

Regards – Pat

[WeldsolParticipant @weldsol]

I was always taught never to reverse turn a reamer even when extracting it always turn the direction of cutting.

With a tap then yes reverse turn to break the chips

 

Paul

[NobbyParticipant @nobby]

Hi William & Guys

You did”t say what material you were trying to ream out. If you have reamed a hole And its still a bit tight on the shaft etc. Its frowded apon I know but you can bump the reamer up by sliding a tool bit along the front of the cutting edge

Nobby

 

[Flying FiferParticipant @flyingfifer]

Weldsol,

You are so right about reaming we were taught the the same as you were. As regards tapping half turn forward (ie cutting) quarter turn back (clears the chips & STOPS that horrible cracking noise when the tap breaks. Use a lubricant as well & if its a deep hole remove the tap or reamer & clean the chips from the tool.

its a long time since I broke a tap or reamer using this method. Having said that I`ll probably break one next time !

Alan

[Bill RuleParticipant @billrule36498]

Thanks everyone, I have a better idea now; I wasn’t actually reaming anything at the time. I have just obtained a quality small tapwrench, and actually got my first reamers, so was tempted to use the wrench, but had that disconcerting feeling that I was falling for a beginner’s trap. I think I have a better-balanced appreciation of the relative “agressiveness” of tap vs reamer.

Cheers,

 

William

[KWILParticipant @kwil]

Wherever possible use spiral point taps for through holes and spiral flute taps for blind holes, that way the swarf removes itself.

[NobbyParticipant @nobby]

Hi Guys & kwil

Blue wizards are a fine spiral taps . For broken taps we use to use a 3 pronged tap extractor.I supose now you just spark them out. is this new technology ?

as apprentice peices i made tap wrenchs in various sizes etc. Has anybody tapped smaller than 10 BA ?

Regards Nobby

 

[adyParticipant @ady]

For broken taps we use to use a 3 pronged tap extractor

 

I noticed that this was possible when I got careless and broke a tap tonight but have nothing like that, nor have I ever seen one up close.

I haven’t really seen anything on ebay about them but found what you mean here.

 

Very handy.

Would have saved me two hours of battering my one into little bits via a pin and improvised anvil.

[Sam StonesParticipant @samstones42903]

To answer Nobby’s question, there are several 12BA screws in my skeleton clock. They hold the hardened end (thrust) plates in position for the bottom bearing of the balance wheel arbor, and the bottom bearings of the two escapement arbors.

Having said that, and this is about tapping and the use of tap wrenches, I have to admit that under these circumstances, I twirled the taps in and out between my finger and thumb.

AND, I was only tapping into brass.

It’s nearly forty years ago so I can’t remember exactly, but I may have assessed the resisting torque versus the tap’s strength together with the squeak coming from the brass/tap, to know when to back off.

If we are talking about screw size, my ego is quickly deflated when I peer inside an old watch.

Regards,

Sam

[Steve WithnellParticipant @stevewithnell34426]

I’ve a horizontal steam engine with screws less than 10 BA…The flywheel spokes are made from old watch keys.

 

 

Steve

[WALLACEParticipant @wallace]

There was a very good article in MEW about the use of reamers – maybe in the digital archive or a back issue is available – I forget the date but it must have been 2 -3 years ago ??

 

W.

 

 

[NobbyParticipant @nobby]

Well done Andy

You found them .That was a posh set ! Sams right you only have to look into an old watch

thats small.

Tapping heads are useful with spiral taps if you have a lot of holes to tap

I use chucking m/c reamers 6 m.m. 1/4″ etc on Mill /dril does any body else use these.

Morse taper ones on my S7 Mk1

Nobby

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