Author Topic: M  (Read 342 times)

spooky

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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

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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.
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RonXBR

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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

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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 »
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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.
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mthee

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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


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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