Ben Hutchings Posted June 22, 2008 Share Posted June 22, 2008 Hi, I am trying to find some bolts to fit a new heavy duty prop to the GT6. I'm told they might be the same sort as used on TR6s.The ones used on the standard GT6 prop are 3/8UNF x 1", and are a bit too short for the fatter flanges on the new prop. Length wise, 1&1/4" bolts would be perfect, but I want to make sure, when ordering, that I get ones that have the correct plain shank diameter. Can I presume that If I order a 3/8 bolt (not set screw) then the plain shank will be the same diamater as the major thread diameter? Am I even making sense?Cheers... Ben Link to comment Share on other sites More sharing options...
Deleted User Posted June 22, 2008 Share Posted June 22, 2008 No and yes Link to comment Share on other sites More sharing options...
piman Posted June 22, 2008 Share Posted June 22, 2008 Hello Ben, if you order a 3\8" x 1 1\4" UNF bolt you should get what you want. Do ensure that it is high tensile and fit new Nylocs at the same time.Alec Link to comment Share on other sites More sharing options...
Dizzy Posted June 22, 2008 Share Posted June 22, 2008 Ben, I agree with the above.The plain portion of the shank will be nominally the same diameter as the thread per BS 1768 (you could ask for "3/8 UNF x 1-1/4 Bolts to BS 1768" to be 100% sure of getting the correct ones, though I would expect them to meet this British Standard anyway).In fact the plain portion is likely to be 'to size' whereas the thread diameter will be a few thou smaller (the thread is truncated - i.e. the top flattened off to avoid binding).Bolts of the correct tensile strength for your job should be stamped 'S' or possibly the metric equivalent '8.8' on the head. You are likely to get this grade anyway as it is a fairly standard stock-holding but, again, specifying "Grade S" in your order would make sure.As you realise, you do need to order 'bolts'. The BS specifies a thread length of twice the shank diameter for bolts, whereas 'screws' will be threaded to nominally two thread-lengths from the head.Pedantically, 'setscrews' are something different altogether, i.e. headless screws used for setting the position of something - such as a pulley on a shaft.I hope this textbook of an answer helps! Link to comment Share on other sites More sharing options...
Deleted User Posted June 22, 2008 Share Posted June 22, 2008 because you wrote "8.8) on the head" and it converted the "8)" into a smile.I've disabled the smileys to write this. Link to comment Share on other sites More sharing options...
Ben Hutchings Posted June 22, 2008 Author Share Posted June 22, 2008 Yes, brilliant, exactly the sort of confirmation I wanted, and thanks for extra info Dizzy.Doug.... thanks for your input :) Link to comment Share on other sites More sharing options...
Dizzy Posted June 22, 2008 Share Posted June 22, 2008 Thanks for that Kevin. However I realised what had gone wrong and deleted my 'why?' posting. I then edited my original posting to remove the wayward smiley. Then your 'reply' to my now non-existent "why?" posting appeared!So now I've confused everyone! If you're still on-line, Kevin, how about you delete your 'reply' and I'll delete this? Link to comment Share on other sites More sharing options...
phil866 Posted June 22, 2008 Share Posted June 22, 2008 No, don't delete anything, I'll think it's me....................Have you a local 'fastenings' shop/business? I have one local called Fenland Fastenings and if I want anything I go in taking any bits with me and they sort me out for pennies. As long as I avoid lunchtime that is! They have not let me down yet. Link to comment Share on other sites More sharing options...
Ben Hutchings Posted June 22, 2008 Author Share Posted June 22, 2008 mmm... no I don't think so. I have found a supplier that'll do 200 for a very reasonable price so I think I'll get them, and resell the 192 spare ;) Link to comment Share on other sites More sharing options...
Deleted User Posted June 22, 2008 Share Posted June 22, 2008 Hutch wrote:Doug.... thanks for your input :) No worries Link to comment Share on other sites More sharing options...
Tim Bancroft Posted June 22, 2008 Share Posted June 22, 2008 Ben, You could call Namrick down in the Brighton area-top company. Link to comment Share on other sites More sharing options...
Ben Hutchings Posted June 22, 2008 Author Share Posted June 22, 2008 Yea could do.. funny how important a rep is. I ordered twice from Namrick based on good reports from others, and both times the order was short/incorrect. They do seem to have the right bolts on the site.I think I might go ahead and order the box of 200 I found and then sell the rest in packs of 8 with nylocks through 'Mere'.Out of interest, would you guys perfer to fit Zinc or self colour bolts? The ones I took off were self colour ones, and I didnt see any signs of corrosion. I found this suprising seeing its proximity to the road, but as James pointed out to me on Messenger, the bolts spend most of their time spinning quickly, so not a lot of chance to pick up much water I guess. Link to comment Share on other sites More sharing options...
Dizzy Posted June 22, 2008 Share Posted June 22, 2008 I agree, the finish doesn't really matter a lot if not prone to corrosion in this location.If the stockist you go to has only one type, I suppose that answers it anyway.If you do have a choice, I'd suggest you go for the plated ones if the price is OK as these will look better when you come to sell the surplus. Link to comment Share on other sites More sharing options...
Clive Posted June 22, 2008 Share Posted June 22, 2008 self colour, zinc takes a little strength away. Black bolts are good, think thats what they used originally. Link to comment Share on other sites More sharing options...
Dizzy Posted June 23, 2008 Share Posted June 23, 2008 Clive, I can't quite agree.Zinc plating affects the strength only on bolts above 'S' range, and then only if electroplated - due to the pre-plate cleaning process which can cause hydrogen embrittlement in high tensile steel. Above 'S' range, and 8.8, they should be mechanically plated. And all should be 'passivated' to protect the zinc itself from corroding (i.e. converting to a white powder).Zinc plating, other than on specials like cyl head bolts, is almost the standard these days. A bit of corrosion and some oil leaks used to be the norm but buyers of new equipment won't accept that now. That's why phosphated and oiled (i.e. 'black') and self-finish (typically brown and rusty) bolts are now seldom seen.Ben, your eight little bolts are causing a big discussion! :) Link to comment Share on other sites More sharing options...
Ben Hutchings Posted June 23, 2008 Author Share Posted June 23, 2008 Yep, all very usefull I'm sure.I am searching for a supplier of plated ones but not found anything so far! Link to comment Share on other sites More sharing options...
lordleonusa Posted June 25, 2008 Share Posted June 25, 2008 Army Navy Grade Bolts x 8: # AN6-10A, for driveshaft/propshaft Army Navy Grade Nyloc Nuts x 8: # AN365-624A, for driveshaft/propshaft Army Navy Grade Washers x 100: # AN960-616, for driveshaft/propshaft all available from Coast Fabrications:http://www.coastfab.com/I am 100% satisfied with their product after all of my original BL bolts kept coming loose on a regular basis.Léon Link to comment Share on other sites More sharing options...
piman Posted June 25, 2008 Share Posted June 25, 2008 Hello all,I have used this supplier and been well served.:- http://www.bernie-bolt.com/He told me once that he bought up a lot of surplus fasteners from the Concord project, so he also has or had some specialised fasteners.By the way, David, your pedantic description of a set screw is what I have always known as a grub screw?Alec Link to comment Share on other sites More sharing options...
Slimboyfat Posted June 25, 2008 Share Posted June 25, 2008 Dizzy wrote:.Pedantically, 'setscrews' are something different altogether, i.e. headless screws used for setting the position of something - such as a pulley on a shaft.!Setscrew is a 'bolt' threaded all the way to the head. I think you have described a grub screw like the other chap said. Link to comment Share on other sites More sharing options...
Dizzy Posted June 25, 2008 Share Posted June 25, 2008 Slimboyfat wrote:Setscrew is a 'bolt' threaded all the way to the head. I think you have described a grub screw like the other chap said. Depends whether or not you accept the terminology specified by British Standards and other national and international standards!As Design Standards Controller for an engine design company from 1972 to 1993, one of my many responsibilities was specifying the threaded fasteners for our engines. I do know the correct terminology!'Grub screw' is a colloquial name for a setscrew, not a proper name. I've never seen it on a technical drawing or parts specification, and I don't think it is used at all outside of Britain.A setscrew can be a 'bolt' threaded to the head, i.e. with an external hexagonal or square head, but it is designed to lock at its leading end (via a dogpoint, cone or knurl for instance), whereas bolts and screws lock at the head end.Didn't mean this to get so serious but I don't like being screwed up. ;) Link to comment Share on other sites More sharing options...
valencia1 Posted June 25, 2008 Share Posted June 25, 2008 far as i'm aware, grub screws do not have any heads on as they can be required to go below the base/surface etc Link to comment Share on other sites More sharing options...
Dizzy Posted June 25, 2008 Share Posted June 25, 2008 valencia1 wrote:far as i'm aware, grub screws do not have any heads on as they can be required to go below the base/surface etcYes, I agree. So a grub screw is a setscrew, but a setscrew isn't necessarily a grub screw! Link to comment Share on other sites More sharing options...
Slimboyfat Posted June 26, 2008 Share Posted June 26, 2008 Dizzy wrote:Depends whether or not you accept the terminology specified by British Standards and other national and international standards!Didn't mean this to get so serious but I don't like being screwed up. ;)No I prefer to work from Triumph terminology and their own fastener hardware catalogue (the bible for Triumph parts purveyors). If we are all going to sing from the same 'choir sheet' then let it be Triumph's. A few generations of Triumph parts men haven't found it wanting, more over their customers have used and understood it without complaint for the past 50 odd years. Link to comment Share on other sites More sharing options...
Dizzy Posted June 26, 2008 Share Posted June 26, 2008 I wasn't saying you shouldn't call it a grub screw. You are free to call it whatever you like, as Triumph may have done.As someone in (I think) Alice in Wonderland said: "A word means what I want it to mean" or something like that -- daft as it is.My point, and it was only a passing comment originally, is that a "bolt" threaded almost to the head is a not a "setscrew".That's all from me on this. I've got better things to do! Link to comment Share on other sites More sharing options...
valencia1 Posted June 26, 2008 Share Posted June 26, 2008 Dizzy wrote:My point, and it was only a passing comment originally, is that a "bolt" threaded almost to the head is a not a "setscrew".That's all from me on this. I've got better things to do!thats what i was taught as well ;) Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Archived
This topic is now archived and is closed to further replies.