• Hi all and welcome to TheWoodHaven2 brought into the 21st Century, kicking and screaming! We all have Alasdair to thank for the vast bulk of the heavy lifting to get us here, no more so than me because he's taken away a huge burden of responsibility from my shoulders and brought us to this new shiny home, with all your previous content (hopefully) still intact! Please peruse and feed back. There is still plenty to do, like changing the colour scheme, adding the banner graphic, tweaking the odd setting here and there so I have added a new thread in the 'Technical Issues, Bugs and Feature Requests' forum for you to add any issues you find, any missing settings or just anything you'd like to see added/removed from the feature set that Xenforo offers. We will get to everything over the coming weeks so please be patient, but add anything at all to the thread I mention above and we promise to get to them over the next few days/weeks/months. In the meantime, please enjoy!

Plug taps

A

Artiglio

New Shoots
Joined
Jan 12, 2021
Messages
233
Reaction score
36
Location
East kent
Good day all

I recently ordered some 7/32 whitworth taps which was meant to include a plug tap, when it arrived it’s for all intents and purposes a 2nd. Supplier tells me that they are supplied like this as an industry standard for taps of this size and that i need to grind it down if i want a proper plug tap. Certainly not what the listing showed and seeing as i can buy a 2mm plug tap rather seems as though they sell taps that effectively just aren’t finished ( the final production process surely should be grinding the tap to the shape required).

Or have i got this completely wrong?
 
Do they have a point on the end? A lot of the smaller BSW taps I own have a pointed tip even on the "plug" taps in sets of three (taper, second and plug) which need grinding down to get right to the bottom of the hole. It's a weird one, and I'm not exactly sure what purpose the point actually serves.
 
It probably doesn't help that the American terminology for taps is just sufficiently different to the UK terminology to be confusing. In the US they call them taper, plug and bottoming where we would call them taper, second and plug. If your supplier got the taps from a company that mostly supplies the US, it wouldn't be surprising if you ended up with a second tap when asking for a plug one.

I've taken to calling them taper, second and bottoming just to avoid the ambiguity.
 
I think Al has diagnosed the problem. With the USA being the dominant market for any non-metric tooling, any non-UK maker is likely to adopt their terminology.
I can't check my own early 20th century examples just now, but I'm pretty sure that the plug taps will properly thread a blind hole.
 
I found the same problem and had to grind one down to complete the job, as it was a very shallow blind hole
 
Dalboy said:
I found the same problem and had to grind one down to complete the job, as it was a very shallow blind hole
Click to expand...
Wot Eee said.

I don't have a set of either imperial or metric first series, having long ago adopted the strategy of buying a single size set of three, or even individuals when I need them (e.g. weird things like #2 UNC for audio connectors). That way I can afford better quality ones, and haven't broken one for absolutely ages.

But I do grind the ends down if needs must.
 
Trevanion said:
Would Whitworth be that popular in the US?
Click to expand...
Unlikely. The largest distributor of all things hardware that I know of, McMaster-Carr, does not carry BSW or BSF taps.

The only time I have ever seen Whitworth hardware was on a co-workers old Norton motorcycle he bought while stationed in the UK. He also brought back a complete set of Whitworth spanners so he could work on his bike, as he did frequently.
 
Trevanion said:
Would Whitworth be that popular in the US?
Click to expand...
I wasn't suggesting that it is. But I think it's very likely that US terms will be copied across a maker's whole range for the rest of the English speaking markets, on whatever sizes they buy.
 
Cheers Gents, the vendor says the point is because the tap is too small to “dimple” the end for the grinding process, and it’s down to me to regrind to a plug tap proper, though the listing shows a picture of a generic plug tap that i’d expect, also why would they not have them ground accurately by the manufacturer as a last process.
But as i only need to do a couplemof holes i might just as well return the plug use the second to start the threads then grind it down to give me the plug i want.
Its to make some drawer pulls made from substitute ivory ( elforyn) that i posted about before , so not going to wear the tap much or be hard to cut.image.jpg
 
Artiglio said:
Cheers Gents, the vendor says the point is because the tap is too small to “dimple” the end for the grinding process, and it’s down to me to regrind to a plug tap proper, though the listing shows a picture of a generic plug tap that i’d expect, also why would they not have them ground accurately by the manufacturer as a last process.
But as i only need to do a couplemof holes i might just as well return the plug use the second to start the threads then grind it down to give me the plug i want.
Its to make some drawer pulls made from substitute ivory ( elforyn) that i posted about before , so not going to wear the tap much or be hard to cut.View attachment 29623
Click to expand...

Looking at those, the second tap would need grinding back more than the bottoming one as there is more of a taper on the second
 
Mike said:
Unlikely. The largest distributor of all things hardware that I know of, McMaster-Carr, does not carry BSW or BSF taps.

The only time I have ever seen Whitworth hardware was on a co-workers old Norton motorcycle he bought while stationed in the UK. He also brought back a complete set of Whitworth spanners so he could work on his bike, as he did frequently.
Click to expand...
If I remember, UNC and Whitworth are extremely close to each other. The thread form of UNC is more 'triangular', but Whitworth has corner relief (and a corresponding rounded top to the thread), meaning it is slightly stronger. The common sizes should (and usually do) fit together.

Camera tripod thread has historically always been 1/4" Whit. But I've recently seen it described as 1/4" 20 tpi UNF. I don't think the actual thread form much bothers the Chinese manufacturers of knock-off Manfrotto tripod accessories. That said, Whitworth should stand up better to repeated threading/unthreading operations, especially if done up tightly, and it has a lower propensity to galling (IMHO)..The same applies to the thread for larger cameras and tripods, which should be 3/8" Whit. I don't like camera accessories in white metal or aluminium made with UNC taps.

I have both UNC and Whitworth 1/4" tap sets from reputable manufacturers**. I recently had to make up a rather crucial camera plate, and spent a while staring at both with a hand lens* trying to determine which I preferred. In the end I went with Whitworth.

E.

*Old 50mm lens used backwards - optically excellent!
**Dormer and Presto
 
You must log in or register to reply here.
Back
Top