A tip from this forum saved my bacon at work.

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Today's little workplace challenge was a broken stainless M3 screw in a high tensile aluminium slip ring housing.
The mangled stub of the broken screw was maybe 2 mm proud of the alloy housing. When running a tap through the three other M3 holes in this assembly, I noticed that those must have been Loctited. This being an aluminium electrical slip ring, costing $$$$$$$ required a careful approach. Drilling out a 3 mm (1/8" ish) stainless screw in a super expensive aluminium part was not something I wanted to try..
So, I used a 75 watt soldering gun, to hopefully heat up the screw enough to burn off the Loctite. After thorough heating, and letting everything cool off, I managed to get a grip on the stub and unscrew it. The brand new "Knipex" channellocks I used were also part of the reason I pulled this off. Anyway, the soldering iron trick was something I learned on this forum. Thanks all!
 
Luck.... where skill and previous bad experiences meet? 3mm screws ARE tough.
I had to remove the four 3mm screws that secure the butterflies to the carb shaft on my BS34's. Seal replacement.
Threads destroyed on all but one screw. I tried the solder gun, no joy. Old & rusted and no bite.
Had to drill on an angle that is perpendicular on two axis, by hand. Got 3 out of 4 perfect. Drifted off into the threads on the 4'th, after my drill bits all dulled. JB weld, 3mm tap, red loctite, goo on the exposed threads....and a prayer. Its running!

All the guys on the forum ARE very helpful. Great resource of knowledge, and some parts every now and then!
If not for 5Twins and gggGary, I'd still be in the garage tinkering. Lots of time saved.
 
3mm screw with loctite?

NO!
That's how it came from the manufacturer. This was a brand new GAT brand multi channel slip ring for up to 400VDC power, mA analog signal lines, high capacity data communication lines, etc, and up to 2500 psi compressed air. Installed in an umbilical cable winch. So quite a complicated and expensive piece of equipment. So I guess they wanted to make sure no loose screws ;)
 
Well done Arctic!!

Unfortunately (for me) drilling out 3mm screws is a common occurrence. The ring plates on our alt rotors are held in place with 6 or 7 of 'em. Sometimes every one needs drilling out. I've literally drilled out hundreds of 3mm screws.
Fortunately, I've gotten quiet good at it.
Even more fortunately, rotors are made from iron, not aluminum. ;)

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3mm screw with loctite?

NO!
Mission critical items get red loctite in my garage. A carb butterfly screw gets loose, the engine is seriously damaged.
In the old days the screw was split in the exposed thread end. They were spread after install with a flat screw driver. Didn't need thread locker.
 
Why?
Source for blade screws was Suzuki, there was no locking provision on the threads.
Threads are peened over or distorted to prevent unintentional withdrawal of the fastener. I’m a bad one for using red Loctite. As long as I’m able to apply a bit of heat, I use it probably 50% of the time. On the last carbs I rebuilt I used blue and pinched the exposed threads on the throttle shaft.

The blue Loctite I have and use is pretty good at securing fasteners. I don’t know what grade they use in Italy but on my Ducati (past) and Moto Guzzi, any fastener with thread locker is a real bear to remove. With those, heat is your friend and it usually doesn’t take too much.
 
Threads are peened over or distorted to prevent unintentional withdrawal of the fastener. I’m a bad one for using red Loctite. As long as I’m able to apply a bit of heat, I use it probably 50% of the time. On the last carbs I rebuilt I used blue and pinched the exposed threads on the throttle shaft.

The blue Loctite I have and use is pretty good at securing fasteners. I don’t know what grade they use in Italy but on my Ducati (past) and Moto Guzzi, any fastener with thread locker is a real bear to remove. With those, heat is your friend and it usually doesn’t take too much.
271 is ok 242 is nutz

For myself, if threads cannot be distorted after assembly and alignment, I use goop, yes as seen on TV!
Frickin shoe glue.

It semi hardens on the threads to prevent rotation. It does not rigidly lock threads, so you can service.

Usually just peen over end thread with center punch.

cliff
 
271 is ok 242 is nutz
cliff

Not sure what you mean here. I use a LOT of Loctite threadlocker at work, mostly 243 and 270. As far as I know, the locking strength/ difficult to unscrew increases with the number. So 242 is weak/ easy to unscrew, and recommended for smaller fasteners. 270 is very strong and most of the time makes it necessary to use heat when disassembling.
 
Thanks for the support. It's all about how hard it will be to get off...next time, and will they stay where their supposed to. One gets loose, game over!

My PO tore the JIS screw heads off.
My bike's next owner can curse me for red LT. I'll be long gone by then. The first set of seals lasted 40 years+.
 
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