mwilkinson Posted February 20, 2012 Share Posted February 20, 2012 (edited) The majority of engine bay misc bolts are M6 x 1mm pitch. That's what I have been using without incident for years now? Edited February 20, 2012 by mwilkinson (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted February 20, 2012 Share Posted February 20, 2012 The majority of engine bay misc bolts are M8 x 1mm pitch. That's what I have been using without incident for years now? Are you not thinking of M6 bolts? The bolts that hold the headlights in, cooling plate on, wings in place, spark plug cover etc etc etc are all M6x1 IIRC. There are a few larger M8 bolts, but I think they are M8x1.25 rather than 1.0, i might be wrong there though as i haven't checked. I just know that I've replaced plenty of M6 bolts over the years with stainless M6 cap screws Quote Link to comment Share on other sites More sharing options...
Scott Posted February 20, 2012 Share Posted February 20, 2012 (edited) http://www.ebay.co.uk/itm/Toyota-Supra-MkIV-TT-Spark-Plug-Cover-Bolts-Set-S-S-/250981065115?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a6fa3219b Those are the kits I have bought in the past, been happy with them on the most part. If you know the lengths you are after you could make the sets up on your own very cheaply, although the type of bolt you are after will obviously impact the cost. Edit: I might be wrong but I think these are what you are after? http://www.ebay.co.uk/itm/M6-Stainless-Steel-Bolts-Hexagon-Flanged-Head-/160729254302?pt=UK_DIY_Material_Nails_Fixing_MJ&var=&hash=item6b1d1d1cc6 I can't see M8 in their shop but I'm guessing they would be available if you asked. They are certainly available from other sellers on there, was just thinking more of a batch buy kinda thing. Edited February 20, 2012 by Scott (see edit history) Quote Link to comment Share on other sites More sharing options...
Dnk Posted February 20, 2012 Share Posted February 20, 2012 (edited) Their just st/st cap heads though so would be much cheaper than the flanged hex heads and should be easily available in whatever numbers you wanted from my local nut & bolt man http://www.pro-bolt.co.uk if you want excotic specialised fastners Edited February 20, 2012 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
Scott Posted February 20, 2012 Share Posted February 20, 2012 Their just st/st cap heads though so would be much cheaper than the flanged hex heads and should be easily available in whatever numbers you wanted from my local nut & bolt man http://www.pro-bolt.co.uk if you want excotic specialised fastners Yeah, I was just pointing out the ones I had used in the past as being M6 and fitting fine. I mentioned that the ones he wanted would be more expensive, not sure if the listing I added with the edit is any good or not, or whether it's a neater dimpled head he is after. Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 20, 2012 Author Share Posted February 20, 2012 As far as I know they are normal, I haven't noticed any fine thread ones. In fact most of the ones I have been replacing have been M6 & M8 iirc. Not sure if Ian is getting mixed up with the head size? (10mm socket and 12mm socket required for the most part). Crap, have I got this all mixed up? I thought M10 = 10mm socket needed, and so forth. I also remembered that I needed metric fine thread for something, I think I've made a disasterour assumption somewhere Can someone tell me what I need It's the bolts that, for example, hold on the rad clamps. The 10mm and 12mm socket ones Quote Link to comment Share on other sites More sharing options...
Scott Posted February 20, 2012 Share Posted February 20, 2012 Crap, have I got this all mixed up? I thought M10 = 10mm socket needed, and so forth. I also remembered that I needed metric fine thread for something, I think I've made a disasterour assumption somewhere Can someone tell me what I need It's the bolts that, for example, hold on the rad clamps. The 10mm and 12mm socket ones Erm.. I told you Posts 27 & 28. Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 20, 2012 Author Share Posted February 20, 2012 (edited) But I like a nice summary, seeing as I'm tied in knots already by assumptions A clear answer to a clear question is key to solving problems I've had a look at those posts again and I recall now that M6 = 6mm *shank* diameter, isn't it. Doh. So yeah, that second link would be about right. Hurrah, they are cheaper. I've had had a shock buying M12 bolts wouldn't I Edited February 20, 2012 by Ian C (see edit history) Quote Link to comment Share on other sites More sharing options...
Hellstrom Posted February 20, 2012 Share Posted February 20, 2012 (edited) Well if you want to get it clarified Mx =metric and how thick the bolt is. i has nothing to do what kind of tool size you are going to need. Most automotive manufactures (eu market) use standard thread on m6,m8 and m10,m12 are usually more fine thread then a standard m10,m12 bolt. also you could try getting 12:9 durability for important things as most bolts by stock are 8:8 strechtype. you will definatly struggle more to snap the 12:9 bolts but beware short 12.9 bolts kinda need threadlocking compound to not loose due to vibration. http://www.ebay.co.uk/itm/M5-BLACK-SOCKET-CAP-Screws-Allen-Key-Screw-Bolts-HIGH-TENSILE-12-9-SMALL-QTY-/270891387853?pt=UK_DIY_Material_Nails_Fixing_MJ&var=&hash=item84b9dcf687 Edited February 20, 2012 by Hellstrom (see edit history) Quote Link to comment Share on other sites More sharing options...
mwilkinson Posted February 20, 2012 Share Posted February 20, 2012 Are you not thinking of M6 bolts? The bolts that hold the headlights in, cooling plate on, wings in place, spark plug cover etc etc etc are all M6x1 IIRC. There are a few larger M8 bolts, but I think they are M8x1.25 rather than 1.0, i might be wrong there though as i haven't checked. I just know that I've replaced plenty of M6 bolts over the years with stainless M6 cap screws Ah you must have misquoted me, I've said M6 in my post Yes, your quite right M6 it is. I use to get stainless bolts from a company called Stagonest but they appear to have gone belly up. Quote Link to comment Share on other sites More sharing options...
Digsy Posted February 21, 2012 Share Posted February 21, 2012 I must admit I did wonder how you were breaking M10 and M12 bolts by accident! I really can't see the point in going beyond 8.8 or 10.9 at a push for anything smaller then an M10 as its very unusual for any kind of standard M6 or M8 bolt to be used in a plastic region (probably unheard of for an M6 in fact). Depending on what kind of bolt head style it is you may find that it is 10.9 by default. I'm pretty sure that once upon a time all socket head cap screws were 10.9 but I just checked the most recent standard and it allows 8.8 too. It also used to be the case the you could not zinc plate high tensile bolts (10.9 and above) because the process made them brittle, so beware anything higher than 8.8 that isn't a black oxide finish or some other dull coating (like the organic matte silver you oftenn find on automotive bolts) - another reason not to go higher than 8.8 in your per-ritty engine bay Metric standard pitches are: M6x1 M8x1.25 M10x1.5 M12x1.75 ...and fine is: M8x1 M10x1.25 M12x1.25 (Pretty sure this was already posted, but you did say you wanted a summary ). To interpret "8.8, 10.9" etc multiply the number before the dot by 100 and the number after the dot by 10. "10.9" would become 1000.90 meaning that the ultimate tensile strength of the bolt material is 1000 N/mm^2 and it will start to yeild (stretch) at 90% of its ultimate strength. "8.8" would be 800N/mm^2 and 80% All critical fasteners (mains, big ends, crank pulley and head) will usually have their material and mechanical properties tied down much more tightly than the international standard, anyway, to ensure consistent clamping when yeild tightened. Its quite rare to find a genuine 12.9 bolt in an OEM application. I was once told that its if you do its sure sign that someone messed up the design I think in the aftermarket world they are used where you would normally use a yeild-tightened 10.9 but you want to be able to keep rebuilding the engine without having to buy new bolts each time. Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 22, 2012 Author Share Posted February 22, 2012 So the upshot is, buy a bunch of M6 bolts and hope they fit? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 22, 2012 Share Posted February 22, 2012 So the upshot is, buy a bunch of M6 bolts and hope they fit? They do fit, been using them for years. I can do a video of me replacing one with an M6 cap screw if you like? Quote Link to comment Share on other sites More sharing options...
Paul Posted February 22, 2012 Share Posted February 22, 2012 They do fit, been using them for years. I can do a video of me replacing one with an M6 cap screw if you like? Ooh, yes please Quote Link to comment Share on other sites More sharing options...
Scott Posted February 22, 2012 Share Posted February 22, 2012 Ooh, yes please I'll add it to my to-do list Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 22, 2012 Author Share Posted February 22, 2012 I'm tempted Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.