Old imperial conduit box lid screws

[Aindowsimon]

Any one know the size of the old imperial conduit box screws ?? I don't have callipers. They look to me like 5/16" screws any help appreciated

 

[Lucien Nunes]

That question dates from 9 years ago but while we're on the subject, odd number BA sizes were much less common but did get some use. FWIW there is still a small market e.g. for rail signal equipment that uses 1BA hardware to maintain backward compatibility.

 

[Chalkperson]

Thank You for this information.

 

[7029 dave]

Thank You for this information.

Welcome to the forum

 

[pc1966]

We used to have some old 19" racks that used 1BA screws, part of an original fax machine (Muirhead-Jarvis I think) used to send photographic pictures between newspaper offices by telephone until the 70s. Somewhere I still have a 1BA nut runner and a couple of related tools.

 

[pc1966]

As an aside, the BA size screws are actually based on metric dimensions, though British and defined/adopted in 1903. 0BA is 6mm diameter but not quite interchangeable with M6 due to the thread profile, while the other sizes (and the nut AF dimensions) are all defined mathematically, unlike the BSW/BSF/UNF/UNC/Metric sizes whire it is more like someboday's choice, but you have more than one...

These days the most useful size spanners to have are 2BA (close to 8mm & 5/16" AF) and 4BA (close to 1/4" AF). Of course if you are doing it properly you have some King Dick spanners:

King Dick Combination Spanners BA - King Dick Combination Spanners - King Dick Spanners - Abingdon King Dick - Brand Catalogues from Lawson HIS

Lawson HIS: Makita, Bosch, Metabo, Dewalt, Power Tool Accessories, Clothing, Safety Equipment and more

www.lawson-his.co.uk

 

[littlespark]

King Dick……

Cue childish sniggering from the back…

 

[Julie.]

That question dates from 9 years ago but while we're on the subject, odd number BA sizes were much less common but did get some use. FWIW there is still a small market e.g. for rail signal equipment that uses 1BA hardware to maintain backward compatibility.

There are certainly odd number sizes, from 1 through 11, then 15 (no 13BA for some reason), here is a small selection of my box of BA taps

I couldn't find a 11BA, 14BA, 15BA OR 16BA tap in this box, but I am sure I have them somewhere.

 

[pc1966]

King Dick……

Cue childish sniggering from the back…

I have a huge King Dick spanner. Always gets a laugh when I whip it out at parties!

 

[pc1966]

There are certainly odd number sizes, from 1 through 11, then 15 (no 13BA for some reason), here is a small selection of my box of BA taps

These folks seem to be selling 13BA nuts:

13BA Brass Nuts Qty 10 - EKP Supplies - Precision Turned Parts for Model Engineering

EKP Supplies sell engineering tools and model engineering supplies, screw manufacturer,

www.ekpsupplies.com

But for sure the odd-number sizes are less common. In fact I can't remember seeing any below 10BA in recent decades.

 

[Julie.]

These folks seem to be selling 13BA nuts:

13BA Brass Nuts Qty 10 - EKP Supplies - Precision Turned Parts for Model Engineering

EKP Supplies sell engineering tools and model engineering supplies, screw manufacturer,

www.ekpsupplies.com

But for sure the odd-number sizes are less common. In fact I can't remember seeing any below 10BA in recent decades.

Yup suppose I should have checked, it makes sense as it would be 18swg , I just haven't come across one, and was convinced that 13BA was non-existent.

 

[Julie.]

I have a huge King Dick spanner. Always gets a laugh when I whip it out at parties!

Yes I have had a few King Dicks over the years.


Err hang on, that didn't come out right

Spanners, King Dick spanners!

 

[brianmoooore]

I had the King Dicks out a couple of days ago.
My MF tractor has imperial fasteners on the oily bits, and metric on the bodywork and all the control stuff for the oily bits, and my selection of AF combination spanners are King Dick.

 

[Julie.]

I had the King Dicks out a couple of days ago.
My MF tractor has imperial fasteners on the oily bits, and metric on the bodywork and all the control stuff for the oily bits, and my selection of AF combination spanners are King Dick.

Yeah, all the ones I have are Whitworth (and old Whitworth at that, not modern 1940's sizes).

 

[nicebutdim]

I have a huge King Dick spanner. Always gets a laugh when I whip it out at parties!

All my King Dick spanners are huge. It was only in recent years that I discovered they also came in smaller sizes.

 

[UNG]

There are certainly odd number sizes, from 1 through 11, then 15 (no 13BA for some reason), here is a small selection of my box of BA taps

View attachment 98770

I couldn't find a 11BA, 14BA, 15BA OR 16BA tap in this box, but I am sure I have them somewhere.

And it looks like the Zeus tables making an appearance as well