Author Topic: M  (Read 705 times)

spooky

  • Posts: 1067
  • Sunny Dumfries
M
« on: October 25, 2022, 06:19:26 PM »
Can someone explain in terms I might understand about metric fasteners please.... If i have a nut and bolt that a 10mm spanner/socket fits what would that be called ?  M10 ?  likewise if I have a bolt that needs a 13mm tool what the M is that ? I want to order a mixture but not sure where to start, 
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mthee

  • Posts: 1884
Re: M
« Reply #1 on: October 25, 2022, 07:33:16 PM »
The M refers only to the diameter of the threaded portion of the bolt. An M6 bolt might need a 10mm socket on it, for example.
Fear of the unknown does not mean the unknown needs to be feared

RonXBR

  • Posts: 272
Re: M
« Reply #2 on: October 25, 2022, 07:41:26 PM »
Hope this helps.

Ron.

RonXBR

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Re: M
« Reply #3 on: October 25, 2022, 07:54:42 PM »
Even bigger bolts!

Ron.

spooky

  • Posts: 1067
  • Sunny Dumfries
Re: M
« Reply #4 on: October 25, 2022, 08:21:22 PM »
Thanks to you both, that`s great... :)    M5/6/and 8 are what i need in stock.
« Last Edit: October 25, 2022, 08:24:04 PM by spooky »
Classic efi squadron blue, CG125, Terrot 125, CM200 sprinter,

iansoady

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Re: M
« Reply #5 on: October 26, 2022, 09:21:17 AM »
I blame the Americans who started the rot by describing fasteners by spanner size - eg 1/2" A/F which is normally for a 5/16" diameter bolt - rather than everyone else who uses the threaded siameter eg metric and BSF / Cycle etc. That chart from Ron is quite helpful. For some reason the Japanese manufacturers use different head sizes to the standard ISO ones - 12mm as opposed to 13mm for 8mm bolt diameters.

The Americans in their usual fashion, refer to their sizes as "standard".....
Ian.
1952 Norton ES2
1986 Honda XBR500
1958(ish) Grumph.....

mthee

  • Posts: 1884
Re: M
« Reply #6 on: October 26, 2022, 03:42:55 PM »
Also important to note the Japanese Industry Standard (JIS) screwdriver against Phillips, as described here;
https://www.motorcycle.com/ask-mo-anything/difference-between-japanese-jis-phillips.html


Fear of the unknown does not mean the unknown needs to be feared

iansoady

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Re: M
« Reply #7 on: October 26, 2022, 03:46:35 PM »
Yes indeed. I like many others must hasve ruined countless screw heads before I found this out a few years ago. My rule of thumb is: JIS will sort of work in Phillips, Phillips will work in Pozidriv. But NEVER the other way round.
Ian.
1952 Norton ES2
1986 Honda XBR500
1958(ish) Grumph.....