western Posted January 18, 2010 Share Posted January 18, 2010 any ideas on what type of drill bit will cut through a chrome molybdenum screw extractor??? I've got the very reluctant to give up remains of a M8 thread water pump bolt in the engine block on my 200Tdi [in the yellow ring on attached photo. engine is presently in my 110 with the timing case completly stripped off, need to get this bolt out as it secures the main water gallery for the pump, really need to get the 110 back on the road ASAP. Quote Link to comment Share on other sites More sharing options...
Jon White Posted January 18, 2010 Share Posted January 18, 2010 Your best bet would be to weld an old nut to the end of the extractor and remove it that way - you;ll find drilling it out to be almost impossible. Jon Quote Link to comment Share on other sites More sharing options...
disco tony Posted January 18, 2010 Share Posted January 18, 2010 You may find it cracks off like a carrot if you weld it Ralph. You could try a solid carbide drill bit, that should do it. Quote Link to comment Share on other sites More sharing options...
steve b Posted January 18, 2010 Share Posted January 18, 2010 Cor its not going very well is it Ralph? Possibly a mechanics worst nightmare ..not sure whether a cobalt drill bit would do it? iirc there is a thread somewhere on here about it, may have been from Astro Al? Is there any easi-out protruding? just wondering if it would be possible to weld a nut to it? Steveb Quote Link to comment Share on other sites More sharing options...
hobson Posted January 18, 2010 Share Posted January 18, 2010 i got some cobalt bits from our local shop, they've gone through everything so far including thick stainless. they were bloody expensive though, i was going to replace my 10mm bit but it was 12 quid! i got a normal bit instead! Quote Link to comment Share on other sites More sharing options...
sean f Posted January 18, 2010 Share Posted January 18, 2010 Screw extractors are generally as hard as ****. Not sure you will be able to drill it with out a pretty special bit, and even then it won't be easy as every thing around it is softer so the bit will tend to walk off to the side. If you can't get enough on it to weld to it (some times the heat from the welding can free things) then often you can shatter the extractor especially if it is already cracked from when it broke and get it out in bits. Not easy or quick especially if the access isn't great and you need to be carefull not to destroy the original thread. This often works on broken taps as well. I think the "official" line is to use a spark erroder, but where you can get one of them from I have no idea. Quote Link to comment Share on other sites More sharing options...
western Posted January 18, 2010 Author Share Posted January 18, 2010 Thanks for the info guys, much appreciated I can obtain cobolt drills fairly easily, but not until friday [back at work] there's no bolt or easyout protruding, it's flush with the block face & don't have access to welding gear Quote Link to comment Share on other sites More sharing options...
hobson Posted January 18, 2010 Share Posted January 18, 2010 just remembered, the best drill bits are called PCD (polycrystaline diamond) used in aerospace etc for titanium and really hard metals. dread to think how much they'd be but at least you know what to look for if you need one. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted January 18, 2010 Share Posted January 18, 2010 Somewhere on the forum, someone recently mentioned some sort of penetrating fluid thats is extremely cold. I'l have a hunt... Quote Link to comment Share on other sites More sharing options...
western Posted January 18, 2010 Author Share Posted January 18, 2010 just remembered, the best drill bits are called PCD (polycrystaline diamond) used in aerospace etc for titanium and really hard metals. dread to think how much they'd be but at least you know what to look for if you need one. Hmmmm, wonder if we've got any of them at work Quote Link to comment Share on other sites More sharing options...
steve b Posted January 18, 2010 Share Posted January 18, 2010 Screw extractors are generally as hard as ****. Not sure you will be able to drill it with out a pretty special bit, and even then it won't be easy as every thing around it is softer so the bit will tend to walk off to the side. I think the "official" line is to use a spark erroder, but where you can get one of them from I have no idea. ..or an ultrasonic bit... the softer material around is the big problem, even with a bit tough enough to cut the broken extractor the problem is holding the drill rigidly enough to go through the centre of the broken extractor. What are the thoughts on burning it out with a fine gas cutting jet? I do have a water pump to do on my 200Tdi, so just covering my bases.. can never learn too much about the get out clauses Quote Link to comment Share on other sites More sharing options...
mickeyw Posted January 18, 2010 Share Posted January 18, 2010 Have to agree with the above, spark erosion is the only real solution. That's how we used to remove broken drills, taps, easy outs etc when I worked as a toolmaker some years ago. However getting an engine into the tank of a sparker would be quite a challenge (this is a submerged process), as would finding a toolmaking firm that has such plant that is still in business. Alternative methods I have employed to remove broken taps: Try to smash it into pieces and remove in bits. You would need a decent quality punch for this, AND SAFETY GOGGLES. This will muller the hole big time. Use a small grinding tool, such as a Dremmel, and LOTS of patience, to grind out what is left. Likely chances are you will need to Helicoil the hole once you have finished Which ever method you try I don't envy you. Good luck. Quote Link to comment Share on other sites More sharing options...
kingrat Posted January 18, 2010 Share Posted January 18, 2010 what about left and twist drills? Quote Link to comment Share on other sites More sharing options...
Diff Posted January 18, 2010 Share Posted January 18, 2010 I have used a fine oxy welding tip with success before. Using a flame with as much oxygen as you can without it going out, just heat the centre of the easy out and it will spit and pop and gradually burn away. Often the heating loosens the remainder of the bolt and it may come out with with a screwdriver if you are lucky. Regards, Diff Quote Link to comment Share on other sites More sharing options...
steve b Posted January 19, 2010 Share Posted January 19, 2010 Thats what I thought , oxidising flame and it should melt out,less potential for damaging the block than drills too Hope you have some luck with it Ralph Steve Quote Link to comment Share on other sites More sharing options...
western Posted January 19, 2010 Author Share Posted January 19, 2010 IIRC a workmate has welding kit, otherwise I'm down to cobolt drills. Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted January 19, 2010 Share Posted January 19, 2010 I have a Defender 200tdi block Quote Link to comment Share on other sites More sharing options...
missingsid Posted January 19, 2010 Share Posted January 19, 2010 As "Easyouts" or similar have a steep slope on the left hand twist is it not possible to use a punch to jar it round clockwise to remove it from the original bolt? After that it would be back to try and remove the old bolt. Marc. Quote Link to comment Share on other sites More sharing options...
redneck Posted January 19, 2010 Share Posted January 19, 2010 Don't bother with cobalt drills they will either break or burn out on a screw extractor, stellite or carbide drills would work but you need to hold them rigidly i.e. drill press, as they are very brittle they also need very high speeds, pistol drills are generally too slow. I have removed many drills and taps with a good punch and a LOT of patience you "just" need to work it forwards and backwards until it loosens up. Good luck. Quote Link to comment Share on other sites More sharing options...
western Posted January 19, 2010 Author Share Posted January 19, 2010 Doubt I'll be able to get stellite or carbide drill bits, certainly can't put the block in a vertical drill, at least not without removing the engine & fully stripping it down plus don't know where in my area to get it done if I can't fix it without a full stripdown. the easy out is the 3rd from front in this set Quote Link to comment Share on other sites More sharing options...
western Posted January 19, 2010 Author Share Posted January 19, 2010 I have a Defender 200tdi block keep it safe, I might have to swap if I can't fix this problem. Quote Link to comment Share on other sites More sharing options...
redneck Posted January 19, 2010 Share Posted January 19, 2010 Personally I never use those screw extractors, they never seem to work very well. I nearly always dress the end of the broken bolt so that its flat and drill it out starting with a small bit and working up in stages to the tapping size. Usually works out quicker, but this kind of thing is my job. You may also try using a die grinder and grind it out (again a lot of patience required). Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted January 19, 2010 Share Posted January 19, 2010 keep it safe, I might have to swap if I can't fix this problem. Got your name on it Westy Quote Link to comment Share on other sites More sharing options...
western Posted January 19, 2010 Author Share Posted January 19, 2010 Cheers Rusty might invest in a dremel kit [got them in my local B&Q] & have a go at grinding it out, I can still see the edge of the bolt remains , so it's not detroyed the thread in the block. really don't want to strip the block down if I can avoid it. Quote Link to comment Share on other sites More sharing options...
white90 Posted January 19, 2010 Share Posted January 19, 2010 I would remove everything in front, rad,grill etc and then attempt to tap the eziout around with a punch line of sight is very helpful in these situations, you may have to remove everything around and try some heat even a blow lamp on it may help it is all I have and so far I have removed all I have snapped include a cylinder head bolt. Quote Link to comment Share on other sites More sharing options...
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