bicykillgaz Posted December 23, 2012 Report Share Posted December 23, 2012 Hi, I'm after making two extended dummy bolts with an m8 thread at the end to use whilst I'm re-bedding and pilar bedding my rifle, I know the bolts are m8 but what mm diameter bar do I need to buy to thread? I think it's 6 or 7mm but not 100%. I'm sure someone on here will know. Atb Gary Quote Link to comment Share on other sites More sharing options...
sitsinhedges Posted December 23, 2012 Report Share Posted December 23, 2012 8mm obviously Quote Link to comment Share on other sites More sharing options...
bicykillgaz Posted December 23, 2012 Author Report Share Posted December 23, 2012 8mm obviously Definitely or is that just a guess? Quote Link to comment Share on other sites More sharing options...
bicykillgaz Posted December 23, 2012 Author Report Share Posted December 23, 2012 (edited) Definitely or is that just a guess? I think your right, it's a 7mm hole you need to drill to tap an 8mm thread isn't it. Edited December 23, 2012 by bicykillgaz Quote Link to comment Share on other sites More sharing options...
sitsinhedges Posted December 23, 2012 Report Share Posted December 23, 2012 Definitely or is that just a guess? An M8 male thread is 8mm in diameter (or fractionally under) an M8 female thread requires a 6.8mm hole to be drilled then a tap is fed in that will create a major diameter of 8mm or thereabouts. Quote Link to comment Share on other sites More sharing options...
bicykillgaz Posted December 23, 2012 Author Report Share Posted December 23, 2012 An M8 male thread is 8mm in diameter (or fractionally under) an M8 female thread requires a 6.8mm hole to be drilled then a tap is fed in that will create a major diameter of 8mm or thereabouts. Cheers mate just got a couple of 100mm lengths ordered and some various length button head and countersunk hex head bolts to suit, just need my new trigger guard and bolt handle from Cz which im gonna get threaded and then to make a replacement bolt knob then I'm sorted should look better. Quote Link to comment Share on other sites More sharing options...
lees Posted December 24, 2012 Report Share Posted December 24, 2012 Get yourself one of these, very useful for this sort of stuff http://www.amazon.co.uk/gp/aw/d/B0000CLZUO (Zeus book) Quote Link to comment Share on other sites More sharing options...
mr salt Posted December 24, 2012 Report Share Posted December 24, 2012 (edited) 7.25 drill to tap m8 hole.(depends on pitch) or are you talking about using a dye(die ) on a bit of bar? Edited December 24, 2012 by mr salt Quote Link to comment Share on other sites More sharing options...
sitsinhedges Posted December 24, 2012 Report Share Posted December 24, 2012 7.25 drill to tap m8 hole.(depends on pitch) or are you talking about using a dye(die ) on a bit of bar? No it isn't, a standard M8 tap requires a pilot hole of 6.8mm. Try googling it. Quote Link to comment Share on other sites More sharing options...
fortune Posted December 24, 2012 Report Share Posted December 24, 2012 Just buy a length of 8mm threaded stud from tool shop and two nuts per pieces needed (not expensive). cut stud to required length and lock up nuts on it to how long you you need. Simple, you've just made your extended bolts. no need for dies or anything just a hacksaw and a couple of spanners Quote Link to comment Share on other sites More sharing options...
Cannon Posted December 24, 2012 Report Share Posted December 24, 2012 You can buy M8 threaded bar in 1 meter lengths for a couple of quid. The hole to be drilled should probably be 6.75mm, but 6.8 will be fine. Quote Link to comment Share on other sites More sharing options...
station Posted December 24, 2012 Report Share Posted December 24, 2012 Just buy a length of 8mm threaded stud from tool shop and two nuts per pieces needed (not expensive). cut stud to required length and lock up nuts on it to how long you you need. Simple, you've just made your extended bolts. no need for dies or anything just a hacksaw and a couple of spanners Good sensible information Quote Link to comment Share on other sites More sharing options...
bicykillgaz Posted December 25, 2012 Author Report Share Posted December 25, 2012 Just buy a length of 8mm threaded stud from tool shop and two nuts per pieces needed (not expensive). cut stud to required length and lock up nuts on it to how long you you need. Simple, you've just made your extended bolts. no need for dies or anything just a hacksaw and a couple of spanners Hi, When I said dummy bolt it was actually a bit misleading, I only need enough thread to screw it into where my action bolt and barrel lug bolt normally go, then the plain shaft will be coated in release agent so the bedding compound doesn't stick to it threads would just complicate it and run the risk of a mechanical lock if I don't get enough release agent on them, a plain shaft will be easier to sort. Good idea though, thanks. Quote Link to comment Share on other sites More sharing options...
fortune Posted December 25, 2012 Report Share Posted December 25, 2012 OK. Wrap electrical insulation tape around bolt. One layer will do. Bedding material wont hold on that and bolt will come out ok when set along with tape. Loads of ways to skin monkey. Quote Link to comment Share on other sites More sharing options...
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