Tap Chuck ?

Hello all.

I seem to remember one of the regular suppliers doing a 2 jaw 'drill chuck' specifically to hold taps on the flats so they don't slip - I think it was highlighted in a MEW 'new products' page.

Did I dream it or do they exist - and if so, who were they as I can't find them anywhere !

thanks.

WALLACE

Chronos did them. I thought they were a great idea. When I went to order one they were out of stock so clearly everyone else thought they were great too. I haven't seen them again

The old style auger drills had a square drive head and the chuck from one of the hand brace style drills could possibly be adapted as they were two jaw but i'm not sure how small the square hole was when fully closed .

Must grab one next time i go to the local junk yard !

I recently purchased a hand tapping chuck from little machine shop ( usual disclaimer and freight was a killer) that is designed to fit in a standard drill chuck mounted in the tailstockor drill pess.

This allows the tap to be aligned but is only turned by hand so very sensitive and made for small taps .

Looks a bit like a big pin chuck with a turned section on the end to fit the drill chuck.

Ian

Hi Wallace,

I made a special chuck for taps that grips the square end of the tap. Details are here:

**LINK**

Mike

Is this **LINK** the one?

Paul

Power tapping by holding and driving only by the square is can unsatisfactory due to alignment issues. There are good reasons why the professional devices, like my Archer and Pollard ones, include a three jaw to grip the shank for alignment. Interestingly the very simplest form of three jaw, as used on hand driven drills, is deemed sufficient. Presumably as there is no requirement to drive so only light jaw pressure is needed.

For geometrical reasons a self centring square is inherently unreliable at holding to close limits, especially with small components. Also, as has been previously mentioned, tap makers do not take special precautions to keep the square truly concentric to the shank and thread form. The way things are done pretty much ensures that the square will be close to concentric but how close is a bit of a lottery. The point is concentric. Examination of the blend from point cone to square gives a reasonable idea of how concentric the square really is.

Clive

That's very neat, Mike

Quite a lot of work; but looks worth it.

[... Clive's point regarding concentricity is well made, however.]

MichaelG.

I've had my eye on this for a while: **LINK**

The device linked to by pcb1962 is essentially similar to those fitted to drive the square on my Archer and Pollard tapping heads. I imagine that, like those there is a certain amount of float to let the device auto centre.

Clive

Thanks everyone for the replies.

SlotDriller - yep, hadn't thought of that, my Dads ancient bit and brace has a 2 jaw chuck but its a bit on the heafty size for the M2.5 tap I want to use.

Mike - I did see your website with the 4 jaw - very nice, but definetly outside my skills limit .

I suppose it might be easer to modify a new or boot sale special Eclipse type - but I wondered about it's accuracy - although if the flats aren't ground 100% accurately (which sounds like they're not !), it's a bit academic. I'll have a look at my collection of taps at the weekensd - meantime, if anyone from ARC or Chronos wants to introduce them, it does look like there's a couple of buyers all lined up for you !

W.

Look on Amazon on the page for Tap Wrenches, there is a tap wrench on the same design as WITTE that has a ratchet drive bothways and a fixed position and has two jaws to cover your tap size.

Cost, £5.99.

Clive

I have what looks to be the same device as that linked to on Amazon in both sizes. Bought a goodly few years back the innards of the larger one failed in fairly short order. Investigation revealed a less than stellar detail design and execution inside the attractive case. As I recall nothing that couldn't be rectified with patience and ingenuity but, in 20 odd years I've not been able to summon up the enthusiasm to either fix or throw! Not exceptionally concentric as I recall matters.

Probably the Sealey set lower down are better but I've got 2 or 3 different breeds of those Vee jaw or collapsing square type tap wrenches and none are truly concentric. Or for that matter terribly firm in the grip. Starting a tap square needs even more than the usual concentration. Certainly no good for power drive. I've no idea whether the relatively poor performance is concept limited or simply a result of compromise to meet the marketing constraints of cost that the customer will pay against performance he can live with.

The common battery drill works well up to 5 or 6 mm given regular reversals, with a suitable torque limit set on smaller sizes, before chuck slip becomes endemic. I've often wondered if a chuck could be reworked to include a square gripper drive behind for the larger taps just like my proper heads. May be a nice project to extract the torque limiting innards etc. for an inexpensive DIY tapping head.

Clive

John [and all],

A timely word of warning about the total cost of importing stuff these days ...

The Customs & Revenue rules changed [November 2011, if I recall correctly]

My Summary:

The UK Customs/VAT threshold rule is:

• If the base price is £15 or less, then no VAT is chargeable, BUT
• If the base price is more than £15, the VAT is chargeable on the base price plus shipping & handling!
• Added to which; ParcelForce makes an outrageous charge for the "service" of collecting the VAT.

... This makes it a very significant threshold. [as I know to my cost]

Caveat Emptor indeed

MichaelG.

I think they were called little goliaths when Drummond did them

2 jaw tapping chuck

They hold taps very firmly

You will have to make your own arbour to fit a B22 back taper socket

In all the time I squirrelled about on fleebay I only ever saw one original 1930s chuck come up for sale, they are quite rare but their usefulness and gripping strength is obvious

Edited By Ady1 on 01/09/2012 09:41:10

Is this any use?

**LINK**

That looks quite a bargain.

MichaelG.

Edited By WALLACE on 01/09/2012 17:06:32

I have the smaller of the two versions available from Warco, total axial travel is approx. 30-32mm minus the amount used to hold it in the tailstock. I have yet to use it but it seems nicely made considering the price.

I have some drill bits with 3 flats ground on, these can not slip in a 3 jaw drill chuck. I was thinking of grinding similar flats on taps, and maybe on a chuck spindle, so can then be held and driven by 3 jaw chuck and battery drill. Trouble is , how? I have a grinder, drill press and lathe, with a drilling spindle for lathe tool post, guess it does not need great accuracy.