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Stuck steel screw in aluminium help!
AdrianH - 12/8/13 at 06:15 PM

This is for a cover off a Yamaha 600CC chopper style bike, model not known, but came to me with a broken screw stuck in it.

Looks as though the aluminium has oxidized and bonded very well to the screw thread. The screw could well have been stainless it was hard to tell.

I have tried my usual welding a nut to the end and failed, in the end the screw finally snapped flush.

I have also drilled down with a clearance drill but cannot remove the remaining bits in the tread.

It is only a M6 thread, the aluminium is approx 8 or 9 mm thick and I have access to both sides, but struggling to remove the steel threads.

Is there something that will dissolve the steel but leave the aluminium that I can get over the counter without raising alarm bells?

Adrian

02GF74 - 12/8/13 at 06:27 PM

There is a way similar to the electrolysis
I need to find the info but it will leavw al untiuched whilst dussilcing the steel

Sirr for slekkjbh usind android phibe

teegray19 - 12/8/13 at 06:29 PM

Good quality stud extractor and a bit of heat will wip it out, I got a snapped head bolt out this way.

Or you could drill 6.8 and tap M8 if the application allows?

rodgling - 12/8/13 at 06:34 PM

Drill & helicoil?

madteg - 12/8/13 at 06:38 PM

Get some good drill bits, start with small drill say 3mm. drill up to 6mm very carefully making sure you stay central. then helicoil it

Wheels244 - 12/8/13 at 06:39 PM

Spark erosion

I did it many moons ago when I was an apprentice to remove a snapped HSS Tap.


http://www.sparkeroding.co.uk/

big_wasa - 12/8/13 at 06:48 PM

quote:
Originally posted by rodgling
Drill & helicoil?


+1 if the oxidisation is that bad the thread may be no good anyway,

AdrianH - 12/8/13 at 06:58 PM

I will try to keep picking at it, try to get an edge and then bash-it.

All else fails then yes helicoil.

Adrian

Mr Whippy - 12/8/13 at 07:02 PM

Type M6 to M8 stud into google and that should give you a solution

Wheels244 - 12/8/13 at 07:06 PM

quote:
Originally posted by AdrianH
I will try to keep picking at it, try to get an edge and then bash-it.

All else fails then yes helicoil.

Adrian


Agreed - maybe my solution was a bit exotic

owelly - 12/8/13 at 08:10 PM

Soak it in vinegar to ease the fuzzy ali.

02GF74 - 14/8/13 at 06:46 PM

ALUM - Otherwise known as Potash of Alum or Potassium Ammonium Sulphate


read about it here:

http://www.tap-die.com/contents/en-uk/d296_Tip_Remove_Broken_Tap_Drill_Reamer_Tap_and_Die_Co.html