TOPIC:

There's this bolt in the cylinder head of a Z400 from 78. Probably best you take a look for yourself:

Much appreciated 

Jon

Try to hit it with an outside multi tooth nut socket that bite into the left over of the philips head.
The power of the impact will loosen the thread binding too!!


 

Yikes. I would start with  heat. A heat gun will be less risky than something with a flame. Get it quite hot, then let it cool a bit, then pour on some Kroil or Liquid Wrench ( they are by far the best penetrants) and use it liberally around where the flange meets the head. I would do this a couple of times a day for several days. 

It looks like the top of the nut has been drilled. If you can see the end of the stud, filling that cavity with penetrant will also help. 

it looks like the nut is completely round. If not, a high quality six point impact socket on an impact gun, or even a hand impact wrench, may be able to grip it well enough to get it loose. If it is really round, then you may want to skip the penetrant and go straight to a Dremel tool with a cutoff wheel. Be very careful that you do not mess up the threads on the stud.

TexasKZ, it´s a allen head screw (not a philips head, stupid me). In Germay we have more form and function related names and not manufacturer/brands related.

skip to 3:51

If you have access to a MIG welder you could weld a hex nut to the top of it (the heat from the welder will also help)

My apologies, I thought I was looking at a head nut.

The first thing I would try is to remove the bolt with these pliers.  As already mentioned, use heat first.

www.amazon.ca/VAMPLIERS-Linemans-Extract...a-383525757080&psc=1

Since it is a bolt instead of a nut and stud as I previously thought, you could just drill the head off, remove the cover or head or whatever you are trying to remove, then you will have the remaining part of the screw sticking above the surface. Lots of penetrating oil and heat and some high quality vice grips should do the trick.

If the threads are not too buggered, you may also be able to thread two nuts onto the remaining part of the bolt, jam them together and screw it out.

I use left handed drill bits on those. Most of the time the bolt unscrews just before the head pops off. If it doesn't the head comes off and you proceed like TexasKZ said.

So Jon99, what did you end up doing to remove said item???

Rick H.

Put a large-ish center punch in the middle of the screw head and hit it with a proper hammer, like a heavy ball-pein.

The impact will help to jar the fastener loose, and the theory is that the concentrated force (of the pointed punch) will be directed along the shank of the fastener and will reduce some of the tension caused by the slight stretching that occurred when the screw was installed.

Also if you're planning to use Vise-grips or similar, put an Allen wrench in the screw head first. If you just squeeze it with the locking pliers, you may deform or break the screw head - that would be less than helpful.

Guess Jon left the building....

Rick H.