Spanners - I'm a bit confused

JackFrobisher

JackFrobisher

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I have a new eyebolt for my pontoon but I don't have a spanner big enough to do it up. I have adjustables and stilsons but I'm not happy with using them when I need it to be done up really tightly. It's also a bit awkward so a ring spanner or a socket would be ideal.

Easy, I thought, just go out and buy one. I can't find one big enough locally so I thought, I'll order one online.

My problem is what size do I order? I Googled it and now I'm really confused.

The thread is exactly 25mm (measured with a micrometer) and the nut is exactly 42.25mm (flat to flat).

Can anyone help with what size should I order?
 
Metric spanners are sized across the flats, so a 43 mm spanner is the correct size. Likely to be quite expensive to buy a ring spanner that size, I think I would go with the adjustable since you have it already.
 
I would use the AJ too, since it's there. What's the point of having it if not for those situations when you need a spanner size you don't have?

Note that if you're doing things up very tight it's best to put it on the bolt such that the fixed jaw is leading. This puts the pressure on the moving jaw close to the frame rather than at the tip, reducing the leverage and any unwanted movement in the jaw.

Pete
 
+ 1 for the adjustable spanner.

I dont think you will find the 43mm spanner that Vyv says will be the correct size. I am not even sure that a 25 mm thread is a standard metric size.

I suspect you may be looking at a 1" whitworth (or BSF) thread or more likely a 11/8" UNF or UNC thread which requires a 111/16" AF spanner.

Good table of spanner jaw sizes at http://www.sat.dundee.ac.uk/~psc/spanner_jaw.html
 
macd said:
It's not, at least in the shortened version (ISO 262). But then neither's 43mm, yet Vyv has one
For 60 bucks you can download the full version, ISO 261, but for that you can probably just buy the spanner and have done with it :)
Click to expand...

Or save the dosh and use the adjustable
 
At that size the adjustable will be an excellent fit. Even if it did damage the nut it isn't as though you are likely to be undoing it again. I stick a bit of pipe over the handle to help on larger sizes. The same logic applies to a stilson. A bit of grooving on the nut isn't going to affect it's performance.
 
prv said:
..Note that if you're doing things up very tight it's best to put it on the bolt such that the fixed jaw is leading. This puts the pressure on the moving jaw close to the frame rather than at the tip, reducing the leverage and any unwanted movement in the jaw.

Pete
Click to expand...

Good tip - never thought of that!
 
Success

Well, that thread went on a bit longer than I expected. Thank you all for your wisdom. I used an adjustable and a piece of iron pipe and it ain't goin' anywhere now.

Thanks.
 
Glad you got sorted. As another tip, if you find you have a big nut to deal with, and don't want the expense of a special spanner just for the one job, a good temporary spanner can be made from a couple of lengths of angle iron and a couple of lengths of studding (or bolts) and nuts.
 
My Dad who was trained on WW2 fighters and bombers always said to use the right spanner for the right job.
Having said that I still possess a collection of American USAF adjustables which my Dad "borrowed".
Thing is though unlike modern cheapie adjustables they are very well machined and jaws remain parallel whatever the opening.
 
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