Mudmonkey Posted February 16, 2007 Share Posted February 16, 2007 Sorry if this is the wrong section and feel free to move it! Quick question as to what size bolts are used for a NATO hitch? I think its M12x150 but have read differently and now not too sure Thanks in advance! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 16, 2007 Share Posted February 16, 2007 The bolts on mine were something like UNF but as far as I can remember M12's do fit OK. Quote Link to comment Share on other sites More sharing options...
Glue Posted February 16, 2007 Share Posted February 16, 2007 Having looked at the Dixon-Bate site the other day, new ones are supllied with 8.8 grade M12 set screws or bolts. Mine however was bolted on with some strange UNF size. I believe that it is quite acceptable to use M12 to replace the old UNF bolts. Glue Quote Link to comment Share on other sites More sharing options...
Lewis Posted February 16, 2007 Share Posted February 16, 2007 I managed to squeeze M14's into mine, and they were 10.9's ooohh get me Quote Link to comment Share on other sites More sharing options...
Mark90 Posted February 16, 2007 Share Posted February 16, 2007 Yep I have found some will take M14's and others only M12. I think it depends how the plates line up when the hitch is assembled. I suspect they are designed to take 1/2" bolts. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 16, 2007 Share Posted February 16, 2007 The fitment on any Td5 onwards Defender has to be four M12's, because the threaded inserts inside the chassis crossmember are metric, either 4 x M12s, or for the other sort of towing hitch, 2 x M16s. Half inch (12.7mm) bolts will fit the hitch but M14s, while they may fit through the hitch, won't fit through the hole in the rear crossmember of an older Defender without making the holes bigger, as they are about 13.5mm. The tensile strength of four M12 8.8s works out as something like 26 tonnes anyway IIRC so M14s are probably overkill Quote Link to comment Share on other sites More sharing options...
rtbarton Posted February 16, 2007 Share Posted February 16, 2007 Originally 1/2 inch UNF on Series vehicles but M12's fitted these days. Length depends on what you have in the way of spreader plates and so on. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted February 16, 2007 Share Posted February 16, 2007 I have M14 hi-tensile socket head bolts on mine with a spreader plate either side of a reinforced crossmember. Les. Quote Link to comment Share on other sites More sharing options...
pugwash Posted February 16, 2007 Share Posted February 16, 2007 how do you tell hi-tensile from other bolts- is their a head marking? Quote Link to comment Share on other sites More sharing options...
Lewis Posted February 16, 2007 Share Posted February 16, 2007 Yes, they are stamped either 8.8, 10.9 or 12.9 on the head. If unstamped they are unrated - avoid these. Most bolts (i.e. those from screwfix etc) are 8.8. Some people talk about 10.8's but I have never seen these myself Quote Link to comment Share on other sites More sharing options...
pugwash Posted February 16, 2007 Share Posted February 16, 2007 i always wondered what 8.8 meant. are these number decipherable in any way? is a 12.9 stronger than 8.8? Quote Link to comment Share on other sites More sharing options...
ciderman Posted February 16, 2007 Share Posted February 16, 2007 The higher the number the stronger the tensile of the fastner . At work we use 4.4 tensile on water main flanges that are designed to break under pressure. Quote Link to comment Share on other sites More sharing options...
freeagent Posted February 16, 2007 Share Posted February 16, 2007 yeah, basically, the higher the value, the greater the tensile strength... i've seen 10.8 bolts, i'm sure there are some on my Disco... For Landrover applications, regular 8.8 bolts are fine... Landrover use higher spec bolts in a couple of safety critical areas (brake caliper mountings and swivel housing mountings for example) and it would be good engineering practice to replace like for like... most socket head screws (hex key screws) are 12.7 rated, and are generally cheaper than 12.7 rated bolts... if you fix a NATO hitch on with 4 M12 x 8.8 bolts, you've got to be doing something seriously wrong to stress them... Quote Link to comment Share on other sites More sharing options...
Lewis Posted February 16, 2007 Share Posted February 16, 2007 Never seen 12.7 either Another way to tell - though not foolproof - is that 8.8 grade or less are usually electroplated, 10.9 grade are usually galvanised, and 12.9 are usually bare steel. there are of course exception so always check the head stamping 8.8, 10.9 and 12.9 are what Land Rover currently uses Quote Link to comment Share on other sites More sharing options...
ciderman Posted February 16, 2007 Share Posted February 16, 2007 Not sure if the others are special order only, But my engineering suplliers only specify 8.8( in bolt head) 10.9(Bolt or cap screw) 12.9 (cap screw). I have jus changed my drive flange bolts for 12.9 Caps Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 17, 2007 Share Posted February 17, 2007 Look near the bottom of this thread http://forums.lr4x4.com/index.php?showtopic=617 in the tech archive, an explanation of the numbers is there. There is also an old "imperial hardness" stamp, some are stamped S and some are T, not sure what they are equivalent to though. Quote Link to comment Share on other sites More sharing options...
rtbarton Posted February 17, 2007 Share Posted February 17, 2007 S & T are found on UNF bolts and indicate the tensile stringth. S is the standard high tensile, T is stronger and I've seen V on flywheel bolts. R is found on BSF bolts to indicate high tensile. Quote Link to comment Share on other sites More sharing options...
western Posted February 17, 2007 Share Posted February 17, 2007 Sorry if this is the wrong section and feel free to move it!Quick question as to what size bolts are used for a NATO hitch? I think its M12x150 but have read differently and now not too sure Thanks in advance! this attachment for EPC should help Quote Link to comment Share on other sites More sharing options...
Mudmonkey Posted February 17, 2007 Author Share Posted February 17, 2007 thanks guys looks like I was right then Quote Link to comment Share on other sites More sharing options...
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