Allen Keys

[Mick F]

I bought a complete set of Allen Keys the other day.
http://www.diy.com/screwdrivers-keys/jc ... 874_BQ.prd

Imperial on the left, Metric on the right.


Long story why I needed them, but all I needed was a 7mm key. The only way I could get one was to buy a set. No matter, because I'm sure they'll get used. The new set feels much better quality than my (cheap worn) previous set, so it's not a bad thing.

What about the Imperial set ???

I know there's a tolerance that these tools and screws are made to, so it should be possible to select the "correct" tool for the job to achieve a good - if not better - fit.

Are Imperial Allen Keys pointless in this day and age, or can you mix and match?

[DaveP]

Sometimes you have to deal with Allen head bolts that are worn, damaged or just cheaply and inaccurately made. A selection of Imperial keys might just offer a better fit from time to time - but probably not on Campag kit

[rjb]

Many years ago I needed a 7mm Allen key to remove the brake calipers on a Ford escort. The handbook mentioned they were difficult to obtain. I carefully filed an 8 mm one down to fit, probably removing the case hardening in the process but it did the job and I still have it in the bottom of my tool bag.

[fastpedaller]

Many years ago I needed a 7mm Allen key to remove the brake calipers on a Ford escort. The handbook mentioned they were difficult to obtain. I carefully filed an 8 mm one down to fit, probably removing the case hardening in the process but it did the job and I still have it in the bottom of my tool bag.

Ah - you've just revealed about the only source of an individual 7mm allen key - the local motor factors! It may be that the 7mm key by itself costs as much (or more?) than the set though, and (if its like mine) is somewhat 'heavy duty' being longer and with a heavy handle on it in order to exert the required torque - but at least it's unlikely to wear out if used on a bike

[Brucey]

in a decent tool shop you will be able to buy 7mm hex bits with one of several different drives on. The other end of the bit could have

Male hex in 1/4", 8mm or 10mm

or

Female square drive in 1/4", 3/8", 1/2"

so there are plenty of choices really.

Another way out of it is to get rid of the stupid 7mm bolts anyway (which I know isn't always possible/easy, but you have to wonder why they fitted the blinkin' things to start with.... )

cheers

[phil parker]

I have to use a few imperial Allen keys, size small, when setting up my [American] guitars and if you try to use the nearest equivalent in metric it will round the bolt head - so I always make sure I have both metric and imperial (I've not done any work on my Triumph Bonneville for a long while, but I need imperial for that!).

[the snail]

but you have to wonder why they fitted the blinkin' things to start with.... )

cheers

Yeah, like the 4.5mm ones on my ritchey stem

[Des49]

What about those daft 3.5mm Allen keys needed for Campag Delta brakes. Absolutely mad.

Nowadays one can find these sort of things on eBay, but before eBay and getting the internet this was almost impossible.

I had a visit from a friend who is a mechanic and motorcyclist, when we were discussing this he remembered some Italian bikes needing weird tools and then recounted an interview in which Valentino Rossi's mechanic was asked what differences he noticed when they moved from Yamaha to Ducati, his response was he needed twice as many spanners!

[scottg]

Metric parts on British Bikes ?, I am confused.

I thought you used Whitworth ? , I've had to file down
cheap metric tools to fit Cyclo-Benelux mechs.

[drossall]

You can buy a 7mm socket-drive one, or a regular one, or go to Amazon.

[Mick F]

Thanks for the info Drossall.
Halfords is either in Plymouth city centre, or out in a retail park 20odd miles from here. B&Q is much nearer.

I was in B&Q for electrical stuff - installing a new electric cooker - and needed a 7mm key for the Fiat500 brakes. (well spotted rjb!)
I also wanted a new set, so I bought them.

It's the Imperial ones that are not needed ......... probably.

[PDQ Mobile]

My old Mirrycle mirror uses a really unusual imperial size (5/64ths or something like that).
I always assumed it was to make nicking it difficul, which it undoubtedly does.

[mercalia]

Halfords you can normally buy separate items
?

[Mick F]

My old Mirrycle mirror uses a really unusual imperial size (5/64ths or something like that).

Just looked, the 5/64ths key is the second size up from the bottom on my set. (Smallest is 1/16th.)

5/64ths seems/looks just the same as the 2mm key.

[Norman H]

Mick F wrote:-

5/64ths seems/looks just the same as the 2mm key.

Yes, some metric and imperial sizes are fairly close.

Over the years I had accumulated a tool shop's worth of Allen Keys, most of which were scattered around various draws or languishing at the bottom of tool boxes. I gathered together a bucket full of them and sat down with some digital callipers to sort them into imperial and metric sizes. I was amazed at the variation. Some could have fallen into either category and one or two appeared to belong to none.