Right ive grown up just associating bolt sizes with the size of the hex head. But when im looking at allen bolts i obviously cant do that. i need to know what size the std typical 10mm headed bolts are. are they m4, 5 or 6??

this is the same thread size as like the punto mk2 rocker cover bolts etc if that helps...

i just dont know what the size is called

mostly M6

EDIT: oh you mean 10mm allen? i think its M12

Munkul said:

mostly M6

EDIT: oh you mean 10mm allen? i think its M12

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i just mean like what is the thread size for your average 10mm headed bolt. like the size of bolt used for rocker covers etc...


does the m5 mean like 5 mm and m6 6mm etc

just wait till you're trying to find M7 bolts...

arc said:

just wait till you're trying to find M7 bolts...

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they are on the racking just next to the rocking horse manure


Yazza look here

http://www.roymech.co.uk/Useful_Tables/Screws/cap_screws.htm

are you onabout scews or bolts
some one else should explane the diffrences
but

bolt
http://www.brolliesnsails.com.au/ashade/images/SCEW-EYE.JPG

scew
http://www.refereeworld.com/catalog...=images/prod/imbusschrauben_8.gif&w=210&h=280

http://www.boltscience.com/pages/faq.htm#14
this is what we are tought at college

Yazza54 said:

i just mean like what is the thread size for your average 10mm headed bolt. like the size of bolt used for rocker covers etc...


does the m5 mean like 5 mm and m6 6mm etc

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yes, M6 by far and wide has mostly a 10mm hexagonal head.

M6 - the M refers to "metric" (and therefore ISO standards) the 6 refers to the outer diameter of the thread.

Daz, no need to nit-pick, although youre right

Much easier since the change to metric but I still find the odd use for my old BSW and BSF stuff (usually when I have to drill and tap a sloppy metric hole. And the AF measurements often caused confusion (referring to the size of the head ('across flat') rather than the diameter of the bolt).

And you sometimes come across instances where someone has managed to force a whitworth thread where a metric thread should be.

At work ours is an old plant, so we have a mixture of BSF, BSW, ISO Metric coarse and fine, and some custom ones as well. It's an absolute minefield.

All good comments but I am going to get pedantic, something obvious is being overlooked. There is no such thing as "Allen-bolts", socket-cap heads yes, Allen bolts no. Allen is a trade name belonging to the makers of a certain brand of hex-key.........calling them Allen bolts is like calling all spanners "Snap-ons" and all vacuum cleaners "Hoovers". Many years ago before I became a desk-pilot and when I used to get my hands dirty for a living I would call them Allen bolts and I used to get my arse kicked as a result by the suits upstairs, now its gone full circle and I delight in doing the kicking......But hey-ho.

i am going to get pedantic too, since a lot of people, myself included, call vacum cleaners "hoovers" and ball-point pens "biros", worm drive hose clips "jubilee clips"

its called brand association, and theres nothing wrong with it in the slightest, as long as everyone else knows what you mean

True, at the end of the day we all know what they are but on the shop floor where you work accurate descriptions dont matter, however in the planning, design, development, procurement etc depts where I tend to hang out it does. Correct part identification specifications and descriptions are a big deal deal. If I put forward a quote, proposal or even a BOM that specified Allen-bolts instead of SCHs it would be sent back to me by my boss/client with a memo asking me if I know WTF it is I am talking about......thats the way things work upstairs, every detail is critical, get it wrong it costs money, compromises client relationships and most importantly of all.............makes you look like a Dick.

not everyone is a big cheese blue-coat though

Munkul said:

not everyone is a big cheese blue-coat though

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We call them 'white hats', due to the supervisors having white hard hats.

Cheers

SPD

Sorry to bump this topic, but what size is the thread for rocker cover bolts?

MFrV1 said:

Sorry to bump this topic, but what size is the thread for rocker cover bolts?

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which rocker cover on which engine?

IIRC the 1.2 8vs rocker cover has M6 bolts with 10mm head.

Munkul said:

which rocker cover on which engine?

IIRC the 1.2 8vs rocker cover has M6 bolts with 10mm head.

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Thanks, I'm looking at getting some before I break them trying to remove the cover.

MFrV1 said:

Sorry to bump this topic, but what size is the thread for rocker cover bolts?

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1/16th metric imperial whitworth.....





Ideally you would tell us what car it is and what engine

Apologies for not being specific enough: I'm looking for the size of rocker cover bolts for a 1.2 8v FIRE engine, fitted in a Mk1 Punto 75.

as i said then.