Which Wrench to Use? A Cheater's Guide

http://en.wikipedia.org/wiki/Monkey_wrench

Let the hollering begin!

Yes, but to whose hollering are you refering... mine at the bad pun on my screen name... or all the mechanics out there with veins bulging from their foreheads because you dared speak to of an adjustable wrench...

I once asked one of our new mechanics for a metric adjustable wrench and he nearly went nuts trying to find one. Finally he admitted to not having one and began to trot over to the tool room for it. I let him get about 30 yards before stopping him and explaining the joke to him. I then sent him for a bucket of steam.

I like the board/cable stretcher gag myself... especially if the guy in the tool room is game... Had a guy go to fetch a board stretcher one day, he came back about 4 minutes later and wanted to know which one, the blue one or the red one... But the metric adjustable wrench is a nice one, someone should write a handbook... 'Fun With New Guys... A Guide to Job Site Shenanigans and Other Diversions'

Yea, and throw in a few real tools to really confuse them. Years ago my brother and I owned a sheet metal shop. We primarily made duct work. One fine day while installing a duct line I asked my helper for my duct stretcher and he refused to get it because he didn't believe that one existed. Finally I went and got it myself, yes it is a real tool, and showed him how to use it. From then on he accepted everything that I told him (including the many uses of the "sky hook"). Ok, sometimes I'm bad.

Far as I can tell (from a quick web-search), hex head AF = screw size x 1.6. Works for M2.5, M5 & M10 anyway.

Hey John,

I'm giving you a GA because you're answer is very much in the spirit of my question... I'm getting lots of good responses and lots of links to charts but what I really want is something I can carry around in my head like 'bolt size x 1.6 = wrench size...' Of course now I need to confirm that it works for more than 3 sizes of bolt... a fun little project, yea!

As per ISO, the ratio is

(Quick excell calculation with the standard ) for non heavy head (there is one heavy head bolts too)

So where is a thumb rule ?

I use almost all metric wrenches and sockets. There are metric numbers that fit just right on all american nut and bolt sizes.

Try it!

Not true! They may fit, but if the nut or bolt is really tight or rusted, a "close" metric size wrench or socket will round over the corners.

been doing it for nearly 20 years with impact guns and everything else hand, pneumatic, and electrically powered as well. Experience has proven to me it works and I have countless coworkers and customers who can back it up!

The American to metric doesn't work though. That strips heads and rounds off corners.

In general practice, I have found that one half will work for 13 MM 9 16 will work for 14 MM, 11 16 will work for 17 mm,3 4 will work for 19 mm.1 inch will work for 25 mm,

1 and 7 16will work for 36 MM.

The conversion factor is .03937 x MM equals inches.As you can see, some of these sizes are loose, and some are tight.A rusted 9 16 exhaust bolt can sometimes be removed using a 14 mm,even if it has been stripped by the 9 16.

OddJob

Ron Seto,

I only use the ones that fit more closely than the right one.

Jon

But in fact sometimes quite the opposite!! There are times when the SAE fits a metric fastener closer than the metric tool and vice versa. If I have a really tight fastener, I check both series of tools to see which one gives me the better fit.

Brave "man in tights",

Thats pretty much what I said.

But you got the good score for it. Must be the nice Avatar picture.

Jon

The use of metric wrenches in imperial bolts (and vice versa) is observed in two occasions:

1. When the bolt or nut has wear and corrosion and the wrench is tightly fitted on it to try to get it out without drilling or grinding or welding or...

2. (more commonly) ... when the poor guy just does not know what he is doing.

Skilled mechanics dont do that voluntarly. Period. No discussion about that. Point to Mr. Ronseto again.

Yep. All that I am saying is that someone that knows what he is doing does not voluntarly uses a tool that has a bad fit on a bolt. Please don't take me wrong...

I've used 10mm when I couldn't find a 3/8s, and I've use adjustable wrenches, when I didn't have proper flats. I've used plyers, and vice grips, and in one jam we took a torch and cut some flat steel to just right then make something to fit the bolt and turn it.

Maybe I am more of a mechanic than I ever meant to be, for I remember every harmful mismatched turn and exult in the ones that were all done with the right tool for the job, no matter how long it might take.

One of the finest days of my life really was spent getting the rudder pivot bolt out of a DC 6 and putting another in.

You simply do not do critical work with the wrong tools unless you absolutely have to.

It appears that metrication needs to be standardized also.

That is interesting. That explains why my VW's use mainly "odd" sized metric wrenches and my Honda's use "even" sized metric wrenches.

Surely you mean to substitute EU and ASIA for VW and Honda?

Incredible how relevant this Guest's comment is regarding the entire thread and it's participants. Isn't it.

Fastest rule; Across the flats socket add even to odd and odd to even with an increase in proportion each mill.

http://mdmetric.com/fastindx/t69u.pdf

You are a real treasure.

How do you manage to use a wrench/spanner on a socket screw?

In combination with a small hex bolt and nut. Depending on the direction of desired movement you may need a second nut as a jam nut as well. Yes. I have had to resort to this in an emergency.

I like it, what does it mean...

Bald Monkey,

You should have mentioned Box wrenches and sockets to eliminate the comments about adjustable spanners etc.

Jon

yah, I know better with this group... it's ok though, at least the mental problems in this crowd are entertaining...

Wildly entertaining. I'm here at work 2 hours after I was told I could leave early just so I can read and reply to this crazy thread. This is to much fun, someone is going to email our parents for sure.

Hairless,

And:

http://www.boltdepot.com/Fastener-Information/US-Metric-Conversion-Table.aspx

This

What about that "god for shaken Whitworth"? Or did that whit-forth the Crapper?

If you need to swap back and forth metric/SAE try these. I have used them and they do work.

http://www.metrinch-tools.com/website/introductie.php?language=gb

Regards

Chas

those are pretty cool...

Interchangeable terms:

"Shifter" - the chemical industry

"Adjustable" - most other places

"AFS spanner" - any f*?&£$& size!

... and here's a metric one!

I always carried a narrow and flexible 6" scale with a sliding pocket clip in my shirt pocket. When in doubt, measure.

Saved me alot of steps between project and tool box when I couldn't get the box close to the work.

Also, after a learning curve you will instinctively know what combination of wrenches will be required depending on the machine's origin. Although there will be the ocassional oddball size thrown in just to mess with your mind. (I can still hear them laughing....)

At one time, I believe someone was manufacturing nuts and bolts with imperial head dimensions and metric threads. I seem to recall they were used on some U.S. made automobiles.

I rate this as the best off topic discussion yet.

LOL

Laser tools make a socket set to fit metric, imperial AF & star bolt sizes. Each socket is labeled with 3 different sizes. I got one when they were half price & it's worked on everything I've tried so far.

Nigh,

This?

Jon

I don't think so, the sockets I have seem to be a fairly standard profile. I'll have a proper look when I get home.

Nigh,

I got the picture from the LASER Tool link you provided.

There is this socket that has a bunch of spring loaded pins that can conform to just about any shape.

Jon

I got the picture from the LASER Tool link you provided.

It must be my memory that's faulty then.

I don't think I'd trust the pins in that socket to take any serious loading.

A friend of mine got one and we abused the crap out of his while it was under warranty! It held up great with every hand powered application we used it in.

But the 300Ft/Lb impact gun test on a seized 9/16" grade eight bolt F'ed it up good.

Still I told him I want one for Christmas!

Nigh,

Memory? What's that?

Jon

So basically what we have determined is that there is one place where the metric system isn't superior to the good old imperial... it's interesting to me that this kind of simple sizing system didn't make the cross-over to metric hardware, maybe if it had we'd be more likely to use it over here...

Wow that was a great run. We'll have to get together and do it again some time. I must go now. Have a Merry Christmas all... or what ever you choose to celebrate this wonderful season.

Just when we've got the whole hexagon head thing sorted out car makers seem to be moving over to star drive heads on their bolts.