chinese taps and such

mooncoon said:
I have one of those tap wrenches but don't use it because I have to lower the drill table before I can use it (after drilling) What I use instead is a small pointed piece of shaft that I turn on the lathe and goes in the drill chuck and which centers in the gap at the top of the tap wrench. It prevents the tap and wrench from wandering sideways back and forth and is particularly useful when using small taps in the #4 to #8 screw sizes

cheers mooncoon
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Yeah, some form of tapping guide is a real boon, esp if you are in a bit of a hurry to get the work done, or if you are at all nervous, such as when tapping with a small tap.

Didja know that the tap you are most like to snap is a 6-32? It has the largest ratio between it's tooth size, and the core diameter of any tap out there.

The little bitty taps have relatively smaller teeth to go with, but the 6-32 got the same size teeth that the rest of the 32 pitch series got, just on a smallest overall diameter. PITA.

I have built myself a fair few tapping aids, all in order to do repetitive jobs (where your mind can go on vacation) or to allow some sense of security when doing a job on which the consequences of failure are rather greater. It can be as simple as a clearance sized hole through a block, to be used as a guide, or as complicated as a freestanding tapping jig, think like a drill press, but with a tap holder that can be freely rotated and lifted or lowered.

No shame in making sure the job comes out good, and while they may not remember you for doing it right, they sure will if you muck it!

Cheers
Trev
 
trevj said:
I usually recommend the CTire tap set, when it's on sale at the usual 70% off (does anyone actually buy at full price?), as you sorta never know when you may need one size or another.

Truth be told, having worked in a shop where we had complete sets of fractions up well past one inch, in both coarse and fine sets, Metric, BA, BSW, BSF sets (for working on old Rolls Royce jet engines), as well as a number set including the Extra Fine series and a bunch of NS threads, buying sets was mostly a waste of money from a practical perspective. The sets are so you have the stuff in hand when the job walks in the door. The taps that got used regularly, all had boxed up spare sets (Starting, Plug, Bottoming) of taps as spares, bought for use.

Whether or not you would tap a gun with a CTire tap is kinda a moot point, unless you want to use screws too coarse to mount gun fittings, as the tap sets do not contain any sizes that are commonly used on guns. At least not for mounting scopes and that like, which are usually finer pitches than the hardware stores stock. So you are pretty much at the mercy of the supplier, or you pick and choose the quality level you are willing to pay for, and buy your taps or sets of three taps on an 'as-need' basis.

My experience has been that guys that cannot keep from breaking a crappy tap, will end up breaking an expensive one too. I have cut, ground, drilled out, and generally extracted, far too many tap chunks, to think otherwise. Cheap carbon steel taps are great for two things. They are sharp as heck when new, and if the guy using them cheaps out and keeps using it when dull, you can soften the broken piece with heat, and drill it or mill it out without having to resort to carbide end mills or dental burrs.
Good quality taps, like any other cutting tool, can be ruined by misuse and overuse. They wear out, and are consumed in use, and it is up to the operator to recognize and accept this as fact. If it's not sharp any more, it does not matter how expensive it was, it's still crap.

Cheers
Trev
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At my old company, there was always that one guy.. like you say no matter what..always breaking a tap.
 
A while back I bit the bullet and got pretty much the whole range of taps out of Brownells through a local gunsmith. It was a pricey step but it ensured me that I was going to get decent quality taps.

The difference between the cheapest and the better is that the cheaper ones are ground totally round then flutes are ground away. This means that there is no back clearance. And that means the thread on the tap rub hard against the hole as the threads are cut. On the better taps the threads are ground in with a two, three or four lobed sort of elliptical form and then the cutting grooves are ground out. This produces some back relief on the cutting threads of the taps and a lot less drag and grabbing. So you're at much less risk of requiring enough torque to snap the tap. This is particularly important on the smaller and easier to snap taps.

I've got a couple of the cheapie sets. I tolerate them for the dies they have in them and the occasional use of a tap in the set which I may not have. But some day I'll bite the bullet and buy the proper dies as well.
 
BCRider said:
The difference between the cheapest and the better is that the cheaper ones are ground totally round then flutes are ground away. This means that there is no back clearance. And that means the thread on the tap rub hard against the hole as the threads are cut. On the better taps the threads are ground in with a two, three or four lobed sort of elliptical form and then the cutting grooves are ground out.
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Interesting. I'm going to compare some of the ones I currently have.
 
amosfella said:
Look for a set from a machine shop going out of business. Or look for an estate sale on kijiji...
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kamlooky said:
I've found the odd good tool at yard sales.
The stray tap too.
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These are good ways to end up with someone else's crap. Useless, or damn near so, unless it's new stuff still in boxes, or you have a tool and cutter grinder friend, who can do a job on them to sharpen them.

Good way to round out the collection of farmer tools for cleaning mung out of threaded holes, but pretty poor for making decent holes.

I will reiterate my previous suggestion that buying a set, esp. a quality set, of taps and dies, is pretty much a waste of money unless they will earn you your keep. It is REALLY easy to drop well over a thousand bucks on a quality tap set, only to find that in the first case, you don't have what you need anyways, and in the second, that you never use most of the sizes. But you paid for them!

Buy the cheapie set, use it to clean out the odd hole or clean up the odd thread, and buy a few decent taps to do anything that needs either threads not covered by the cheap set, or threads that are used a lot, once the cheapies are worn out.


Cheers
Trev
 
I don't know why one would buy a 'tap set'... especially if they are cheap...

By a quality tap for the job and it will last a long time... by them as you need them... and you won't have a bunch of sizes you don't need.

I hold the tap in the drill chuck and turn it by hand to thread the previously drilled hole. Seldom break a tap this way..
 
Lots of good advice here on taps. Biggest problem I found when working for the bigger outfits was (1) the department using the tools were not the ones buying them. Supply chain always went cheap. (2) most tools like this came out of a tool crib you never knew what the last user did with it. (3) No matter how many times you would tell some one not to use a power tool on the taps (the larger taps) they would and return a totally F-up tap.

As for the small taps and dies look for the better named ones the kind a machine shop would buy. always clean and replace them back in the holder or case it came in. And take your time. there is nothing worse then having to tear some thing apart totally to try and get a broken tap out.

One thing I will say about cheap taps if you break one it is usually easier to get it out. But a good name brand one does a way better job and usually it easier to do the job

As for a good named brand they the ones I was used to seem to be not around any more so I won't list them.
 
The taps we use at work are Guhring. They are the best taps we've ever used. But 2 or 3 that you use the most, and then buy as needed.
 
I cry a little bit when I see folks that keep their taps all in a little tray so they clank and rub against each other. And then I shudder in near pain when they stir them around with a finger or one of the larger taps to find the one they want down at the bottom of the tray.

Don't be one of those misguided souls. The job done by the tap relies on a keen cutting edge. And nothing ruins "keen cutting edges" like rubbing against other taps which are just as hard. Either keep them in the original packs like wce suggested above or drill out a block of wood to hold the taps in a convenient way.

A dull tap is a hard cutting tap. And a hard cutting tap is one which could easily break.
 
Someone else's used taps are about as good and trustworthy as someone else's used needles as far as I'm concerned.

Top 3 brands are Guhring, OSG, Emuge, no real order, they all do great stuff, sadly they don't do much for odd size/pitches which a lot of guns use.

With Taylor Tool you sometimes have to buy a set, as in a Taper, Plug, Bottom set. Not to be confused with "one of every size in a box" sets, that are largely indeed a bad investment.

For drills, PTD Cobalt Screw Machine(aka STUB) drills are pretty awesome, and not too much $.
 
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Over the years I've bought some taps from KBC that were marked "made in Poland". They proved to be superb. So I suspect that there's no lack of good companies out there and some offshore no-name options are fine as well. But generally only those name brand or no-name options from proper industrial suppliers. The usual big box consumer stores are not the place to shop for such things.
 
guntech said:
I don't know why one would buy a 'tap set'... especially if they are cheap...

By a quality tap for the job and it will last a long time... by them as you need them... and you won't have a bunch of sizes you don't need.

I hold the tap in the drill chuck and turn it by hand to thread the previously drilled hole. Seldom break a tap this way..
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I buy a cheap tap and die set, to have on hand a number of tap and die sizes for the odd job that comes along, for cleaning out mung from threaded holes, and the dies for cleaning up the odd damaged external thread.
Not making money with them, and they serve adequately for the intended purpose. And they didn't cost me a thousand bucks, to have sit there in wait.
The odds of finding a set that has many useful gun work taps in it it almost nil, an even better reason to not buy a set if doing gun work. But for general purposes mechanicing for myself, doing hobby machining projects, and for to have for when I need them, they are a good purchase.

Also, having any tap of the correct pitch and diameter combo, is better than a two hour drive, several days wait or both, to get it 'when I need it'.

Cheers
Trev
 
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