ThreeSheds Posted April 12, 2018 Share Posted April 12, 2018 I have never seen this before - I presume that there is a good reason, perhaps so that when it's corroded to fcuk (like the other one in the photo) you can put a cold chisel in there and give it a tap? Also - do I now need to use a washer as opposed to the flanged nut and bolt that I would normally use (without washers) in this situation... I have been mucking around with cars for 56 years so I am quite embarrassed to have to ask this! Quote Link to comment Share on other sites More sharing options...
mickeyw Posted April 12, 2018 Share Posted April 12, 2018 38 minutes ago, ThreeSheds said: ......perhaps so that when it's corroded to fcuk (like the other one in the photo) you can put a cold chisel in there and give it a tap? Not a bad suggestion ^^^ But - is is to do with a providing a single continuous outer cut path for the CNC profile cutting? Looks like the profile was cut by plasma or similar. Nuts - I think I'd stick with a decent quality flanged nyloc nut. Quote Link to comment Share on other sites More sharing options...
Sheffield Posted April 12, 2018 Share Posted April 12, 2018 I would not use a nylock nut on an exhaust flange. I would use two stainless steel nuts as a main nut and lock nut and to cover as much of the stud as possible. This might give a chance of getting it off again without a battle in the future. Quote Link to comment Share on other sites More sharing options...
Snagger Posted April 12, 2018 Share Posted April 12, 2018 Brass nuts are the norm. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 12, 2018 Share Posted April 12, 2018 Yup, go brass, a nylock will just melt and be no different to a normal nut. Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted April 12, 2018 Share Posted April 12, 2018 Plasma cutter should plunge through the center of the waste in each hole, then cut the shape of the hole. Switch off, move and repeat the same for all the holes, then cut the outside last of all. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted April 12, 2018 Author Share Posted April 12, 2018 Never been too fond of brass nuts just on the basis of strength - I normally use stainless in an attempt to beat the corrosion. Never had one come loose yet and also never had one I couldn't undo later. I did wonder about those 'flashed with copper' ones but in the end I decided to stick with stainless. So... If a plasma cutter can easily plunge through etc, do we still have no consensus as to why the slots are there?... Quote Link to comment Share on other sites More sharing options...
steve b Posted April 12, 2018 Share Posted April 12, 2018 true enough VB , but that design means 2 pierces to cut one piece , full holes brings it up to 5 , it's the number of pierces that limit the life of a plasma tip rather than cut distance in production plasma cutting . there would also be a time saving too over a 4m x 2m sheet of those parts .... time is money and all that cheers Steve b Quote Link to comment Share on other sites More sharing options...
Gazzar Posted April 12, 2018 Share Posted April 12, 2018 Not water cut? Anyway, weld them up and proceed as normal. G. Quote Link to comment Share on other sites More sharing options...
ballcock Posted April 13, 2018 Share Posted April 13, 2018 Aren't they useful for squirting a release oil into the thread. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted April 13, 2018 Author Share Posted April 13, 2018 2 hours ago, ballcock said: Aren't they useful for squirting a release oil into the thread. But they will also let salty water into the thread... Quote Link to comment Share on other sites More sharing options...
Escape Posted April 13, 2018 Share Posted April 13, 2018 On occasion I've had to cut such slips in a standard flange just to get the (broken) studs out. I used washer afterwards, and never had problems. So I kinda like the idea of the slots as a factory feature. Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted April 13, 2018 Share Posted April 13, 2018 23 hours ago, Gazzar said: Not water cut? Anyway, weld them up and proceed as normal. G. Cost 10 times a much to water jet, thats either plasma or laser. Quote Link to comment Share on other sites More sharing options...
Gazzar Posted April 13, 2018 Share Posted April 13, 2018 Didn't know that. Our local prototype people use water. They don't charge much, so I figured it was similar cost! Quote Link to comment Share on other sites More sharing options...
HoSS Posted April 13, 2018 Share Posted April 13, 2018 Its for thermal expansion, avoids stress cracks and/or warping. http://www.davidenglish.com/swift/Tech/Manifold_Design/manifold_design.html 1 1 Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted April 13, 2018 Author Share Posted April 13, 2018 9 minutes ago, HoSS said: Its for thermal expansion, avoids stress cracks and/or warping. http://www.davidenglish.com/swift/Tech/Manifold_Design/manifold_design.html Expansion Slots Even with a properly selected material, heat expansion can still cause flanges to warp and/or destroy the fasteners holding them on. Cutting simple slots along the flanges can do much to provide them with sufficient room to safely expand without doing any damage. Excellent! It all makes sense now Quote Link to comment Share on other sites More sharing options...
Daan Posted April 13, 2018 Share Posted April 13, 2018 On 12/04/2018 at 6:35 PM, Bowie69 said: Yup, go brass, a nylock will just melt and be no different to a normal nut. On 12/04/2018 at 4:51 PM, Snagger said: Brass nuts are the norm. On 12/04/2018 at 3:47 PM, Sheffield said: I would not use a nylock nut on an exhaust flange. I would use two stainless steel nuts as a main nut and lock nut and to cover as much of the stud as possible. This might give a chance of getting it off again without a battle in the future. K-nuts are the nuts.. Daan Quote Link to comment Share on other sites More sharing options...
HoSS Posted April 13, 2018 Share Posted April 13, 2018 35 minutes ago, Gazzar said: Didn't know that. Our local prototype people use water. They don't charge much, so I figured it was similar cost! noo water jet is way cheaper than laser Quote Link to comment Share on other sites More sharing options...
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