Remove remains of stainless machine screw?

[chevy2]

Removed loads of broken bolts that were flush in engine blocks etc,
Best way i found was to hold a nut over the broken stud (an m8 nut would suit an m5) and fire a hot mig blast down the middle and then wind the nut while hot,
Pretty successful but can sometimes take a couple if goes.

 

[Crater Creator]

Easy outs are the work of the devil. I broke two off in glowplugs and had no end of bother getting them out. They laugh at cobalt drills. Now I would try every other option first. I threw all my easy-outs away after that last carry-on.

 

[Jonathan Webb]

Removed loads of broken bolts that were flush in engine blocks etc,
Best way i found was to hold a nut over the broken stud (an m8 nut would suit an m5) and fire a hot mig blast down the middle and then wind the nut while hot,
Pretty successful but can sometimes take a couple if goes.

Interesting. My MIG is u/s at present. I have carbon arc rods - would that be a bit vicious?

 

[winchman]

Slot drill is possibly the best option.
I in the past have fabricated a plate with a bush welded to it to guide the drill bit and have had a lot of good results with these.
https://www.powertoolsdirect.com/ri...3c2Ui-rIIXALx1jYcj0ftOTos62THVxwaAnutEALw_wcB

 

[Pete.]

A stainless screw stuck on an aluminium outboard chassis for 20yrs ain't coming out with a screw extractor.
If the end is flush or almost flush I would hold a thick washer flat over it and tig weld it to the remains, then tig weld a nut to the washer. Since you only have a stick welder available I would make a drilling guide and simply drill it out and if that wrecks the threads, tap for m6.

 

[piman]

Hello Jonathan,

whatever that screw holds, is there the option to redrill that component and then drill the casting and retap, i.e. forget the original fixing position. 5mm is small so all the above options are very difficult indeed?

Alec

 

[Jonathan Webb]

Hello Jonathan,

whatever that screw holds, is there the option to redrill that component and then drill the casting and retap, i.e. forget the original fixing position. 5mm is small so all the above options are very difficult indeed?

Alec

Hi Alec,
The screw is sunk into a well on the cowl so that the head won't catch. If the existing place becomes unusable, that would be an option, using a domed hex bolt.

 

[500e]

The Rigid type seem to be the best of a bad idea your problem is the corrosion give the acid a good try maybe a couple of days with regular changes
But tend to agree with Pete 20 years it is in there for the duration drill guide & sort it out after.
We also use Speed outs but they only remove screws with damaged heads

 

[chevy2]

Interesting. My MIG is u/s at present. I have carbon arc rods - would that be a bit vicious?

I doubt you wiil be able to do it with arc rods as you ideally need to initially focus the heat on the broken stud and then pull the weld pool up and onto the inside of the nut,
Fyi, tig will work ok.

 

[addjunkie]

If you take all the other bolts out does the cowel come off leaving a bit sticking up

 

[james butler]

this is the problem with stainless in aluminium.
galvanic corrosion takes place and pretty much welds the stainless into the threads.
ultimately i think it would be easiest to drill it and tap a new thread or even helicoil it.