My turn - a spanner size

[bigginger]

Anyone know the correct spanner size (not the 'a blah fits' option, I've tried that) of the bolt head highlighted below?


Just noticed I highlighted a hole - OK, the bolt that SHOULD be there
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[alex_holden]

Funnily enough, the one I have here (from a Wolseley 1500 cylinder but it's probably the same) has a 2BA head. It's not a 2BA thread, but the head fits absolutely perfectly in a 2BA socket. It's 0.320" AF, and 2BA is 0.324" - that's snugger than a snug thing during national snuggling awareness week.

[bigginger]

Hmm - tried 2BA with no joy. Doesn't seem to quite fit anything AF, Whitworth of metric - it's infuriating, and it needs to be a good fit as it's a 40 year old corroded bolt with no space for the Mole grip solution, and I'm reluctant to get the grinder out
a

[alex_holden]

Cut a slot in the head with a Dremel, then use an impact driver and a big hammer?

[Orkney]

Pretty sure i removed one of those with a 10mm socket.... just cant remember if it was a 6 sided internally one or one of halfords corner grippy ones.
Assume youve tried some heat on it BG?

EDIT : Had to use a metric not through being a heathen but through lack of proper spanners for the mog

Dear Santa ......

[dunketh]

I used a metric socket too - I also think it may have been 10mm, definately six sided in my case.

Its the one beneath the cylinder I can never fit anything to.

[alex_holden]

Its the one beneath the cylinder I can never fit anything to.

The one I have next to me is exactly 1/2" AF.

[bigginger]

We're talking the smaller of the 2 bolts, boys - the bigger seems to be around 1/2 inch AF, certainly, but the little one isn't quite 8mm or any of my imperial spanner sizes - closest is 2 BA. What I was after was the ACTUAL size of it - and yeah, I know the various ways of helping it to come out, but it would be handy to have the right tool for the job
a

[Orkney]

Ah that little beasty !! fluked that one with a really poor quality 7.5mm IIRC (so poor quality that none are the sizes they say quite)

[alex_holden]

7.5mm is too small: 0.295"
8.5mm is close: 0.335"
11/32 is not quite as close: 0.344"
2BA is perfect: 0.324"

I suspect the bolt head is rusty or rounded, stopping the 2BA socket going on.

[bigginger]

So do I- but a little drilling and finessing with a grinder and chisel and it's gone. As for the people who managed it with a 10mm socket - how? did you pack it out with weld or something? 2 BA will work on the replacement - and it did remove a different one
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[bmcecosse]

There are various head sizes for that annoying little screw!! I've certainly got more than one - and I just range along the small sockets till one fits - can't say I've noticed which. I have considered just doing without - but so far i have always put it back - but not too tightly!

[HarryMango]

I too have found various sizes for this one - I think originally it was 3/16BSF (1/8Whitworth head) but I have used 11/32AF and the last cylinders I bought used 10mm.

Rog

[bigginger]

Thanks, Roger. The four I've been playing with (so 8 of the bolts) seem toy have various different sizes, sometimes on the same back plate. This old car thing is a laugh sometimes, innit...
a

PS Now having the same problem with big end cap bolts too. Curses

[youngun]

Sounds like you need more sockets!

You think its bad on the Mog, try finding the right socket on any part of a Jowett Javelin. They used AF, Whitworth, BSF, and Metric on all parts of the car.....whatever was to hand after the war i guess. Still, it makes finding the right socket for that stuck bolt/nut a total nightmare!

[bigginger]

Nope, I have many, many sockets and spanners of all flavours. This is the second engine on which I've had problems with these bolts though
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