Scooterotica

One of the barrel studs has stripped some of its thead. Can someone direct me to a correct time cert or helicol or is it better to use a over size bolt i see beeddpeed do some?

Think i may go the 3 8ths oversize but what drill size and tap do i use ?

I think it depends on what size the originals are and what size one you are going to use.Are you suggesting you retap the hole 3/8ths Imperial?

Yes 3 8ths whitworths what ever that means

I don't think so 3/8 Whitworth has too coarse thread unless you are using the same thread stud. I you are going to 9mm the standard coarse thread is 1.25 pitch. Std. 3/8 (UNF) fine has a pitch of 1.2mm close enough but too large a diameter. Whitworth is 1.6mm

Unless there is something about your chosen stud I don't know of or that is what the stud manufacturer recommends?

Haven't used whitworth since the seventys when I played with my dad's tools soooooolong ago

Most industry hasn't used any Imperial sizes since the late '60's. Except maybe in the US and even then rarely. For construction industry maybe where they use bulk nuts and matching bolts to go through holes drilled with Imperial drills.

https://www.beedspeed.com/fastener-repa ... -8206.html this is the stud in question

Don't mess about with whitworth leave them in the last century just buy a m8 helicoil kit cheap enuff of ebay

Yes dont mess about with whitworth, either use a timecert (which are stronger than a hellicoil) or get the stud hole welded up, drilled and re-tapped.