Juggalo Posted July 7, 2016 Posted July 7, 2016 Can someone help me out, I'm a bit confused on bolt sizes. I always thought that an M10 bolt would have a 10mm head...for a 10mm spanner. M13 - 13mm head, etc.. So I want 17mm stainless bolts for my exhaust, but they don't do an M17. Quote
Ekona Posted July 7, 2016 Posted July 7, 2016 M10 has a 10mm wide body, but the head is bigger. Quote
Juggalo Posted July 7, 2016 Author Posted July 7, 2016 Not sure. Think I have a spare bolt.. So it has a 8.8mm thread (size stamped on the head) and a 17mm head. Still confused which M size that would be Quote
GMballistic Posted July 7, 2016 Posted July 7, 2016 Not sure. Think I have a spare bolt.. So it has a 8.8mm thread (size stamped on the head) and a 17mm head. Still confused which M size that would be The "8.8" has nothing to do with what size it is as it relates to the tensile strength of the bolt. On bolt heads you can get all sorts of stampings on them including: a manufacturers mark, tensile strength, what grade they are ("A270" stainless steel for example) or various marks/symbols to indicate all of the above etc. Link: https://www.google.co.uk/search?q=markings+on+a+bolt+head&rlz=1C2TEUA_enGB574GB574&biw=1366&bih=643&site=webhp&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjS_Z_spOLNAhXIBcAKHW6bCFMQsAQIIg#imgrc=_ Although there can be some variants on the head size (spanner needed) depending on the country of origin. More info: http://stainlessautomotivefastenings.co.uk/pdfs/HEXAGONHEADIDENTIFIER.pdf Quote
Juggalo Posted July 7, 2016 Author Posted July 7, 2016 Ah right ok, didn't realise that. So I'm looking at an M10 for a 17mm spanner. Cheers Quote
GMballistic Posted July 7, 2016 Posted July 7, 2016 Ah right ok, didn't realise that. So I'm looking at an M10 for a 17mm spanner. Cheers Yep but as I mentioned there can be some difference on head size/spanner needed depending on the country of origin for the bolt. Hence why I put up the table picture & the link to another size table. Quote
Juggalo Posted July 7, 2016 Author Posted July 7, 2016 Ah right ok, didn't realise that. So I'm looking at an M10 for a 17mm spanner. Cheers Yep but as I mentioned there can be some difference on head size/spanner needed depending on the country of origin for the bolt. Hence why I put up the table picture & the link to another size table. Uh Think I'll find a fastener supplier rather than order offline. Better to be sure I guess. They need to standardise this stuff. Quote
GMballistic Posted July 7, 2016 Posted July 7, 2016 Uh Think I'll find a fastener supplier rather than order offline. Better to be sure I guess. They need to standardise this stuff. I usually go to a local supplier called Phoenix as they're so cheap for decent stainless steel bolts/nuts/washers etc and as you say you can see exactly what you need so mistakes don't get made. Screwfix do have bolts too btw and I'm sure there'll be a branch local to you. I bought a mixed set from them years ago similar to the one below... Link: http://www.screwfix.com/p/mixed-nuts-bolts-washers-pack-a2-stainless-steel-500-pcs/10425#product_additional_details_container Quote
Juggalo Posted July 7, 2016 Author Posted July 7, 2016 Yeah, there's a screwfix by my work. I'll give them a try tomorrow Cheers Quote
Stutopia Posted July 7, 2016 Posted July 7, 2016 Pro bolt make it nice and easy to buy online with confidence, particularly when you want something a bit fancy. https://www.pro-bolt.com 1 Quote
Tricky-Ricky Posted July 7, 2016 Posted July 7, 2016 With metric bolts the number IE M6 =6mm, is the size/dia in mm, as already said the head size can vary depending on application/maker etc, there are also fine and coarse thread pitches for some sizes/dia. 1 Quote
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