Tie Bar Castle Nut Size?

[Zack]

Hello All,
Is the Castelated nut used on the end of the Tie Bar an odd size? I couldn't find one that would work in my local hardware store. Anyone know of a source to get just the nut - my tie bar itself is okay.

Thanks!

[Dean]

The Morris Minor suppliers will have them by the bucket load. Just google Morris Minor suppliers.



Edit - sorry didn't realise you were in the US.... it'll probably be an old English imperial size and not a US imperial.

[Zack]

Yes I suppose I should mention I am in the US so that makes getting some of these parts much more difficult. I will make an order from a UK supplier if need be, though I would obviously like to find something closer to home.

[bmcecosse]

I suspect they are 3/8" BSF - but - someone who REALLY knows will be along in a minute!
If you look at the top of this section - there is an excellent list of 'spanner sizes' made up by Mr Ginger. He lists this nut as being 5/16 Whit - which again I 'think' is the same as 3/8 BSF. These older spanners are usually double marked - and the BSF size should refer to the thread size. Here's a handy link from the Landy Owners - which explains it all! http://www.landroverclub.net/Club/HTML/ ... BSF_BA.htm

[Dean]

Conversion chart here.

http://www.baconsdozen.co.uk/tools/conv ... charts.htm

[Zack]

Wow I'm learning lots about BSF thread!

I found this very interesting and a bit amusing:

Whitworth spanner markings refer to the bolt diameter rather than the distance across the flats of the hexagon (A/F) as in other standards. Confusion also arises because BSF hexagon sizes can be one size smaller than the corresponding Whitworth hexagon. This leads to instances where a spanner marked 7/16BSF is the same size as one marked 3/8W. In both cases the spanner jaw width of 0.710 in, the width across the hexagon flat, is the same. However, in World War II the size of the Whitworth hexagon was reduced to the same size as the equivalent BSF hexagon purely to save metal during the war, and they never went back to the old sizes afterwards. Thus it is today uncommon to encounter a Whitworth hexagon which takes the nominally correct spanner.

So I should order the 3/8" BSF castelated nut. Got it.

[bmcecosse]

Yes - I 'think' so - but best to measure the thread on the tie bar - to check it is 3/8".

[Zack]

I'll check that before I order.

Thanks for the help guys!

[katy]

Zack, please note that the tread angle on WW and BSF is 55 degree as compared to 60 degree on UNF and UNC.
Some of the thread count on WW and BSF is the same as UNF and UNC and some are different.

[riley1489]

Hi,

The (original) tie bars on my 1965 Riley 1.5 (surely identical, at least threadwise, to a similar vintage Minor) are 3/8" UNF. I know that for sure as i recently refurbished mine by removing them, running a 3/8" UNF die down them & fitting new nuts as per above.

Incidentally, I had a problem locating the position of the hole for the split pin, as the original had rusted fast and I had to shear them off by unscrewing the original castillated nut (using some blowlamp assistance too). I couldn't find the hole to re-drill / punch out the pin, and the bar itself seems to be made of hardened steel so I couldn't even re-drill a fresh hole. In the end I dipped the threaded end of the bar in some hydrochloric acid (left over from a petrol tank internal de-rust), and this revealed the location of the hole as it removed the rust around the outer perimeter of the remains of the old split pin. Thus saved the bar for another potential 45 years of service.
Chris

[bmcecosse]

Well - I could never get an AF spanner or socket to fit - always had to be whitworth - I think your 'die-nut' has MADE it into a UNF thread!

[autolycus]

By a somewhat indirect route: the Moss catalogue gives the part number for the nut as AJD8406Z.

http://www.lbcarco.com/parts/nut-3-8bsf ... D8406Z.htm says it's 3/8 BSF

Many UNC and BSW threads could be confused with each other (same pitch for given diameter), but the only UNF/BSF confusion might be between No 10 UNF and 3/16 BSF, and between No 12 UNF and 7/32 BSF, but these aren't too common. 2BA is also very similar to 3/16 BSF.

There really shouldn't be any confusion between 3/8BSF and 3/8UNF - the UNF thread is visibly much finer, and the hex (A/F) size is nearly 40 thou smaller.

Kevin

[littleblackflash]

I'm thinking of removing mine because the rubber bushes have worn. I have the bushes but there is so much underseal on the nut I can't see if there is a split pin or not. Anyone know?

[kittyfell]

It should be locked in some way - if it's a castle nut then there should be a pin, otherwise it should be a self-locking nut. Clean the underseal off - gas blow torch - or turps.

[katy]

I checked our '61 last night and they are definately 3/8" BSF, with split pins.