How hard is gauge plate?

I apologise if I have offended you. I certainly had no intention to do so. I'm just trying to explain how different it is here. It is a completely different culture here in Italy. DIY is uncommon.

More generally everyone relies on specialists here, I'm sure it is simply a moneymaking exercise. People don't even apply for their own driving licences, or pensions, or passports. There is always an office to go to where someone, a business rather than the state, will do these things for you.

You even have to pay someone to calculate the equivalent of the council tax for each individual property every year. This is despite the council knowing exactly what you owe them.

It's very frustrating.

A plug tap is the last in the sequence of hand taps to be used. It has a very short taper, 1 to 1.5 times the thread pitch. One might get away using only a plug tap in brass, but not in gauge plate. If only one tap can be purchased buy spiral flute taps. They are machine taps intended to blind holes, but are fine when used by hand.

Andrew

No offence taken … it was just a simple statement.

I sincerely hope that you find a suitable supplier, but I’m obviously not familiar with the current import regulations in Italy.

MichaelG.

oh well, back to eBay

This is described as a machine tap. Would it work? From Germany. Euro 15 each plus 10 for shipping, to tap 4 holes. My mistake for ordering plug taps.

Yes that would work & looks like a decent German brand.

Tony

Do you still have your BSW tap you had before you ordered the expensive UNC plug tap? Is it a taper tap? If so, run the BSW taper tap through the hole first, then finish it off with the UNC plug tap.

It maybe worth investigating here **LINK**

or look for OMPS & Noma around the Brescia or Gardone VT area, lots of gunmaking and Engineering in that area, OMPS is very much aligned to that trade but if you ask either company if they can recommend where you can get what you want.

John

Yes, I still have the BSW taps. Remind me what the difference was, I'm afraid I got a bit lost with all the discussion, is it just the thread lead angle?

Yes, The only difference between 5/16 BSW and 5/16 UNC is the irrelevant (in this instance) angle of the sides of the thread profile. As I told you before I have been using the two interchangeably for years. So has just about everyone else in Australia due to circumstances similar to your own: shortage of local suppliers and extortionate shipping and import costs.

Run your BSW taper tap through the hole first and then finish it off with your UNC plug tap. It really is that simple. May not be world's best practice, but needs must. It will work. I have been doing it for over half a century now and never before heard that "It can't be done."

Yes, it's a spiral point tap, intended for machine tapping of thru holes; the swarf is pushed ahead of the tap. Like spiral flute taps they work fine when used by hand.

Andrew

I buy from China ,without those strange high charges.

Do not know about postage but should be reasonable coming from Germany. "Form A" does have a slightly longer lead but this "form B" should also be OK. Niko.

**LINK**

https://www.gewindebohrer-shop.de/gewindebohrer-schneideisen-maschinengewindebohrer-verstaerktem-schaft/maschinengewindebohrer-durchgangsloechermit-verstaerktem-schaft-form-4022835745105-p-631.html

Edited By speelwerk on 07/03/2022 11:31:56

But I'm guessing you're not in Italy?

All couriers here charge 5% or minimum 18 euro for handling fees. The post office, which is divided up into different businesses, charge a minimum of 9 euro, but SDA, still the post office, are classed as a courier.

VAT is calculated at 22% of the total cost including shipping.

I did look at Amazon.jp as you pay the VAT etc upfront and it's delivered by DHL within 4 days but the costs always came out more or less the same, and most of the taps for sale seemed to be Chinese anyway.

Things are still changing. Everything went mad after Brexit. I'm still waiting for a Parcelforce parcel sent on the 25th November. Tracking stopped early January and I just asked Paypal for my money back.

Thanks for the link.

I just gave up looking and ordered from Germany. The two taps were E25 plus E9.99 shipping.

If in doubt, grab any piece of scrap metal and drill and tap a 5/16 or 1./4  or whatever BSW hole  in it and see if your UNC bolt screws into it. Then try the same again with your BSW taper tap followed by your UNC plug tap and see if there is any noticeable difference.

EDIT Just read Michael Gilligan's post. So 5/16 or 1/4 or whatever UNC. They are all the same as BSW except for 1/2" which has a different number of TPI. All interchangeable.

But now i am confused by what is meant by 10 x 24  UNC.

If it is in fact 10-24 UNC, then 3/16 BSW taps will do the job. Same diameter. Same TPI. Job's good.

And BTW, you don't need a plug tap if you are tapping right through 1/4" plate. A taper tap run all the way through will do the job.

Edited By Hopper on 07/03/2022 11:51:17

Edited By Hopper on 07/03/2022 11:54:59

Edited By Hopper on 07/03/2022 11:57:37

Edited By Hopper on 07/03/2022 12:00:30

Edited By Hopper on 07/03/2022 12:03:00

Oops

Having just read Hopper’s post of 10:06:43 __ I realise that I mis-interpreted 10x24 as 10-24, and suggested a supplier on that basis. [… or did I ? … see edit]

How very embarrassing !!

MichaelG.

.

Ref. __ I have to drill and tap 4 through holes in a 1/4" strip, 10x24 UNC and 1/4".

.

Edit: … Having seen Niko’s recommendation … I am now struggling to know for sure.

Edited By Michael Gilligan on 07/03/2022 11:57:29

The instructions, which are American say "#10-24" and 1/4”-20. I'm a woodworker so I'm not used to the terminology. I assumed that this meant a size 10 24TPI UNC.

Gauge Plate may be annealed but it can still be tough stuff. I’ve broken an M4 tap in it before. I’ve also stripped the teeth on a hacksaw cutting it due to some kind of hard inclusion.

OK. Both of those are the same diameter and TPI as 3/16 and 1/4 BSW.