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geekhack Community => Keyboards => Topic started by: GeorgeK on Sun, 24 May 2015, 11:20:16

Title: IBM Model F Nut Size
Post by: GeorgeK on Sun, 24 May 2015, 11:20:16
Does anyone know what size nuts are in the back of the Model F?  I have found a couple of results suggesting 7.5mm (9/32") but can't find a definite result.  It's definitely not 5.5mm as I have a 5.5mm nut driver and it doesn't fit...  I also can't seem to find any 7.5mm nut drivers anywhere in the UK which makes me think that it might actually be 7mm not 7.5mm...  Typically I have a 7mm bit in a little set but it's too fat to fit down the holes  >:D

Thanks in advance

GK

Edit:  I have one of these http://www.axminster.co.uk/wiha-t-handle-nut-drivers for my Model M and it's perfect.  They don't appear to make a 7.5mm which is what is making me think that it's a 7mm instead.
Title: Re: IBM Model F Nut Size
Post by: fohat.digs on Sun, 24 May 2015, 11:22:45
Yes, it is 9/32" and the 7.5mm will work.

If it is a 122-key terminal, there are a few more inside at 1/4" and/or 7/32" if I remember correctly.
Title: Re: IBM Model F Nut Size
Post by: GeorgeK on Sun, 24 May 2015, 11:25:08
Yes, it is 9/32" and the 7.5mm will work.

If it is a 122-key terminal, there are a few more inside at 1/4" and/or 7/32" if I remember correctly.


Damn - best carry on searching for a 7.5mm one then.  It's not - it's a PC/AT - I'm only taking it apart to clean it rather than do anything more drastic :thumb:
Title: Re: IBM Model F Nut Size
Post by: samwisekoi on Sun, 24 May 2015, 11:36:48
Yes, it is 9/32" and the 7.5mm will work.

If it is a 122-key terminal, there are a few more inside at 1/4" and/or 7/32" if I remember correctly.


Damn - best carry on searching for a 7.5mm one then.  It's not - it's a PC/AT - I'm only taking it apart to clean it rather than do anything more drastic :thumb:

Could be worse.  Could be Whitworth!  I had a '63 Triumph Tiger Cub and had to make or modify spanners to fit *some* of the dang hardware.

(https://upload.wikimedia.org/wikipedia/commons/thumb/c/c8/5-8_vs_5-8_003.jpg/640px-5-8_vs_5-8_003.jpg)
Two spanners, both nominal size 5/8"...

Compared to that, 9/32" is a breeze to find, even in Jolly Olde!

 - Ron | samwisekoi
Auto-typed by my JD45 keyboard.

Title: Re: IBM Model F Nut Size
Post by: fanpeople on Sun, 24 May 2015, 17:37:49
I bought this from ebay (US) and it works well.

http://www.ebay.com.au/itm/Wiha-26556-7-32-x-60mm-Precision-Nut-Driver-/161702122128?pt=LH_DefaultDomain_0&hash=item25a6329290

Title: Re: IBM Model F Nut Size
Post by: dorkvader on Sun, 24 May 2015, 18:32:59
Yes, it is 9/32" and the 7.5mm will work.

If it is a 122-key terminal, there are a few more inside at 1/4" and/or 7/32" if I remember correctly.

Interior is 1/4. I just take the nut-driver bit out of my screwdriver to get those.

Of course some model F have clips instead of nuts internally. The 104-key "unsaver" for the CAD terminals is one.

Yeah finding 9/32 can be difficult even in the US. Not a common size at all. I couldn't get any locally and had to look online (the ones I got are actually rated for imapact wrenches, and barely fit)
Title: Re: IBM Model F Nut Size
Post by: fohat.digs on Sun, 24 May 2015, 18:52:32
I bought this from ebay (US) and it works well.

http://www.ebay.com.au/itm/Wiha-26556-7-32-x-60mm-Precision-Nut-Driver-/161702122128?pt=LH_DefaultDomain_0&hash=item25a6329290



That is the size for a Model M.

Auto parts stores are your best bet for "long, thin-walled" sockets.

Nut drivers will usually have to be ordered from ebay, and are cheap, if you can wait.
Title: Re: IBM Model F Nut Size
Post by: jayeye on Sun, 24 May 2015, 19:08:09
It's been a while since I've seen a Type F, but IIRC the hex-cap screws are the same as the type M; they are 7/32''. Unlikely you'll find them in England; I've found it harder to get inch tools in Europe than metric tools in the USA.


Something to watch out for is that there is very little clearance between the hex head and the screw well; ordinary nut drivers, of the sort of thing that come in a kit won't fit.


Anyway, amazon.com delivers to the UK even if amazon.co.uk doesn't have what you need.
Title: Re: IBM Model F Nut Size
Post by: chyros on Sun, 24 May 2015, 19:30:38
It's been a while since I've seen a Type F, but IIRC the hex-cap screws are the same as the type M; they are 7/32''. Unlikely you'll find them in England; I've found it harder to get inch tools in Europe than metric tools in the USA.


Something to watch out for is that there is very little clearance between the hex head and the screw well; ordinary nut drivers, of the sort of thing that come in a kit won't fit.


Anyway, amazon.com delivers to the UK even if amazon.co.uk doesn't have what you need.
Everywhere in Europe it's all metric units, yeah, but here in the UK it's actually mostly retard units actually. Don't forget this is where it came from in the first place :p .
Title: Re: IBM Model F Nut Size
Post by: fohat.digs on Sun, 24 May 2015, 19:43:35
These particular equivalents work perfectly:

5.5mm for 7/32"
7.5mm for 9/32"

The originals were surely Imperial measure but that does not matter. The narrow throat requiring automotive-style sockets is the larger problem.
Title: Re: IBM Model F Nut Size
Post by: dorkvader on Sun, 24 May 2015, 19:45:23
It's been a while since I've seen a Type F, but IIRC the hex-cap screws are the same as the type M; they are 7/32''. Unlikely you'll find them in England; I've found it harder to get inch tools in Europe than metric tools in the USA.
As Fohat.digs said, it's 7/32 for the M and 9/32 for the F. Yeah Metric bolts and such are not too uncommon here. Even without all the foreign cars, lots of things follow Metric here. Computer case screws for example.

That said, while I can roll down to the local auto parts store and get a 5.0mm nutdriver, they wouldn't have a 5.5mm. They might have a 7/32 but usually not.

Something to watch out for is that there is very little clearance between the hex head and the screw well; ordinary nut drivers, of the sort of thing that come in a kit won't fit.

I do recommend a thinwall ,like you said, but the model F has a little more clearance, so the not-very-thin Impact wrench nutdrivers i have still fit.

For the Model M though I strongly recommend the Wiha picofinish 265P thinwall 5.5mm nutdriver, though my cheap chinese set probably gets more use.
Title: Re: IBM Model F Nut Size
Post by: GeorgeK on Mon, 25 May 2015, 06:17:38
Haha I'm such an idiot on two different fronts...

#1 - I had another look this morning and the bolts have grooves cut into them so you can just use a regular slot head screwdriver...

#2 - I have a cheapy toolkit that came free with a magazine subscription - the screwdriver 'handle' fits the bolts and is also small enough to fit down the holes in the back of the model f...

Thanks for all the help anyway!
Title: Re: IBM Model F Nut Size
Post by: kmnov2017 on Mon, 03 February 2020, 10:20:39
I can confirm that for the F122, one needs a 7mm nut driver. Even though folks have mentioned 7.5mm, the 7mm driver WILL work. The chance to finding a 7.5mm in Europe is very very difficult.
Title: Re: IBM Model F Nut Size
Post by: treeleaf64 on Mon, 03 February 2020, 10:38:43
5 year old thread necro!  :D