Striped barrel stud

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johnny650
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Fri Mar 09, 2018 8:13 pm

check that the length of the helicoil thread is the correct length for the stud. Most Helicoil kits include 10x coils but they are usually very short.
You'll probably need to order some separate extra long coils with the kit
https://www.ebay.co.uk/itm/M8-x-1-25-V- ... H_F09FZxMA

https://www.ebay.co.uk/itm/Professional ... SwGPxaBbZ5

onthelam
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Sat Mar 10, 2018 3:38 am

boxofbits wrote:
Fri Mar 09, 2018 10:23 am
https://www.beedspeed.com/fastener-repa ... -8206.html this is the stud in question
OK that will work 3/8 is 9.5mm.

So now it all comes down to price and availability. Can you find a 3/8 Whitworth tap set for the same or less than a 8mm Helicoil thread repair kit which comes with its own drill and tap set.?

Edited: Correct drill for 3/8 Whitworth is 5/16 or Correction 7.9mm. I misread my Zeus book :oops:

The history of Whitworth threads has noting to do with the process of drilling holes or cutting new threads. Many old bolts with Whitworth size heads requiring Whitworth spanners in fact had metric threads. Even back in the 1920"s :o

:idea:
1): I would not be tempted by something that does not have Helicoil on the packet or anything that says "Helicoil type"
2): If using helicoil there are instruction either on Helicoil site of on Loctite site for inserting Helicoils with Loctite on the outside of the threads.
Last edited by onthelam on Sat Mar 10, 2018 9:47 am, edited 1 time in total.

Grumpy225
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Sat Mar 10, 2018 7:11 am

Scooterdude wrote:
Fri Mar 09, 2018 6:10 pm
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.
Second that. Do it right with an insert or weld/tap it. There's usually enough material around the cylinder studs to do it right.

Scooterdude
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Sat Mar 10, 2018 8:48 am

Grumpy225 wrote:
Sat Mar 10, 2018 7:11 am
Scooterdude wrote:
Fri Mar 09, 2018 6:10 pm
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.
Second that. Do it right with an insert or weld/tap it. There's usually enough material around the cylinder studs to do it right.
You have to be very acurate though otherwise your cylinder wont slide over the studs. Mark Broadhurst did mine and made a seperb job.

onthelam
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Sat Mar 10, 2018 10:00 am

I am fine with your opinion but fail to see how drilling and taping a larger thread is "messing around".

I mean if we re weld we still have to drill and tap. We could also drill and re-tap to 10mm instead of 9.5mm but then we have to find a stud. . The OP has already found a source for the stud.

We still have to drill straight for the thread insert just as we do for the larger thread. 8.3mm vs 7.9mm ( common 5/16) and then also re-tap the threads. (I'd do it in two stages 7.5mm first)

The only advantage I see using inserts is that one has extra bits left over for the other three studs!

Each to their own. There are many ways to skin a cat but it can only be done once.

onthelam
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Sat Mar 10, 2018 10:22 am

I am OK with your opinion but I fail to see how drilling out and taping to a larger sized thread is "messing around"

We still have to drill out the original hole larger 8.3 for the insert and 5/16 or 7.9 for the larger thread. ( two stages? 7.5mm then 7.9) Surely welding and re-taping is more "messy" for the average person.

We could drill out and re-tap to 10mm but then the OP has to find some custom studs and he already has a source for the 9.5 mm ones.

The only advantage to inserts that I see is that a kit comes with extras for the other 3 studs!

There seems to be a resistance or reluctance to use "Whitworth" for some reason. It is simply another standard. Yes not used much anymore except on BSP pipe threads( still used throughout Europe today) and reportedly Leica for their lens mounts.

Maybe if it were called M9.5 it would be OK?

Scooterdude
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Sat Mar 10, 2018 12:13 pm

onthelam wrote:
Sat Mar 10, 2018 10:00 am
I am fine with your opinion but fail to see how drilling and taping a larger thread is "messing around".



Because it’s always better so standardise and keep things the same, you can do this by using an identical stud to the other three by either using a time cert or to make a better job cut back and weld the case up and cut a new thread the same as the others.

Not by drilling a bigger hole and using a coarse whitworth stud that will probably dimensionaly be quite different from the other three.

holty
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Sat Mar 10, 2018 1:56 pm

if the tread is no good, then it will have to be tapped to a larger size, i belive that beedspeed sell a cylinder stud that has an oversize thread on the casing end, ive just checked and it is whitworth, so you would just need to get a tap and recut the thread, it should make a good repair as the stud is the same diameter over the rest of its length as a standard stud, they also do a second size oversize stud with a 10mm thread on the end, you might have to be carefull to get the stud far enough in to get the shoulder level with the gasket face, maybe use yamabond on your base gasket as well to give a good seal, i would say they can be used to do a very good repair.

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