Whitworth Screws

[Silver Creek Sunbeam]

Looking for a set of Whitworth screws (4) for a seat rebuild on my dad’s Series V.
Used is fine as long as they are in good shape.
None of the parts houses seem to have them. I even checked with Sunbeam Spares in the UK, which is where I got my last set, but came up empty.

Thanks to anyone who can assist.

 

[sunalp]

Hi Tod,
Happy New Year!
If those are the 4 screws that thread into the frame I've gotten them from Curt at Classic
Sunbeam. Not sure if they're Whitworth though but I used them and they worked fine.
Cheers!
Steve

 

[fireroad]

Nothing on the car is Whitworth, all UNC!

 

[Asm109]

Not true. A couple of screws in the seat frames ARE whitworth.

 

[hartmandm]

Nothing on the car is Whitworth, all UNC!

They are not all UNC. There are a bunch of UNF fasteners, some British Association fasteners, British Standard Fine, British Standard Whitworth, ... From the parts manual:



Mike

 

[puff4]

Furthermore, a great many fasteners on the Lucas & Smiths components are also ‘Whitworth’ (BSF/BSW/BA), as they never converted many products to UNC & UNF. (Also true of S.U. carburettors, but of course Alpines never had those as factory supplied components.)

 

[puff4]

Not true. A couple of screws in the seat frames ARE whitworth.

True enough, but I always wondered why that was the case. The seats were built during a time when Whitworth had already largely been phased out. Indeed, they’re one of the most modern components on the car, having a design that was well in advance of most of the other seats available on comparable vehicles at time (i.e. being 3-way adjustable). It’s very much a riddle to me why they would have had Whitworth fasteners. The only thing I can think of is perhaps the seats were originally invented for an aircraft that was designed in the 1950s. As we know, the interior on Alpine was created by a designer who was known for designing aircraft interiors. That’s why, for example, when the gauges are all reading properly their needles should be pointed straight up, as you would find on a well sorted aircraft instrument panel. It’s also why we got dimmable warning lamps. So maybe the seats came from something the designer had already produced many years earlier, in which case they may well have incorporated Whitworth in the original drawings. It would be interesting to investigate if a 1950s British aircraft shared seats of a similar design.

 

[Barry]

Looking for a set of Whitworth screws (4) for a seat rebuild on my dad’s Series V.
Used is fine as long as they are in good shape.
None of the parts houses seem to have them. I even checked with Sunbeam Spares in the UK, which is where I got my last set, but came up empty.

Thanks to anyone who can assist.

Unless you are doing an EXTREMELY authentic restoration, this would be a good opportunity to change the two oddball Whitworth fasteners on each seat frame to UNC fasteners. With the exception of 1/2", the only significant difference between BSW and UNC threads is the angle of the thread shoulders (55 degrees for Whitworth and 60 degrees for UNC). Run a UNC tap through the female side and then use readily available UNC bolts. Unless the female threads are "as original", you can probably skip the UNC tap.

Not trying to say that there is anything wrong with the authentic oddball BSW fasteners, just pointing out a simple solution to the BSW availability issue.

 

[Mike O'D]

The Whitworth screw threads into the "gear" for the seat back lock - it's hardened steel. I originally had the same thought - no dice!

 

[BEpine]

My screws were rusted in and snapped off on both seat frames. I drilled out all 3 holes out with a 1/4 drill and used these screws from McMaster-Carr, Black-Oxide Alloy Steel Hex Drive Flat Head Screw, 1/4"-28 Thread Size, 2-3/4" Long Part #91253A-323, and used nylon lock nuts.
Worked perfect.

 

[Pete S.]

Looking for a set of Whitworth screws (4) for a seat rebuild on my dad’s Series V.
Used is fine as long as they are in good shape.
None of the parts houses seem to have them. I even checked with Sunbeam Spares in the UK, which is where I got my last set, but came up empty.

Thanks to anyone who can assist.

I restore vintage British Motorcycles. These guys have saved the day more than once for me.

https://britishfasteners.com/

 

[Mike O'D]

BEpine - actually talking about the short relatively large diameter slot-head screw.

 

[Silver Creek Sunbeam]

Nothing on the car is Whitworth, all UNC!

I am rebuilding my third set of seats. I can 100% assure you that two of the screws on each seat are Whitworth, as I've replaced them before. My issue is that the replacement screws were available then but I have been unable to find then currently.

 

[Silver Creek Sunbeam]

Hi Tod,
Happy New Year!
If those are the 4 screws that thread into the frame I've gotten them from Curt at Classic
Sunbeam. Not sure if they're Whitworth though but I used them and they worked fine.
Cheers!
Steve

I guess I could call or email him. I couldn't find them on his site. It's worth checking out.
On another note...long time no talk. I sent someone your way a month or so ago and he said he's on your waitlist.
Hope you are well...need to get the emails going again and catch up!