Cheap Carbide Drills?

The studs on the exhaust of my astra are locked fast. They sheared off when I tried to remove the nuts, and then the stubs of stud sheared when I tried to get them out. I've ground them flush, heated to red heat to soften, but they work harden like crazy and are eating my HSS drills.

The ideal solution could be a couple of carbide drills, one as a pilot of about 5mm and an 8mm to complete the hole - but the prices I can find are £££ and I need in a hurry in the Burton upon Trent area. Any ideas?

Neil

Neil

Previous threads have suggested masonry bits could work. Bosch do some "multi construction" TCT drill bits, that are claimed to be able to deal with masonry, steel, concrete etc. The sizes that you're after are about £2-£4 each and available in Toolstation, Screwfix and B&Q so you should be able to get them today.

Keith

I would second Neil before i put an edge on the masonry drills using the green wheel on the bench grinder and i worked fine.

Al.

Have you tried countersinking a nut and migging it to the bust stud? The heat breaks the bond and you just wind it out.

Thanks for the 'Leo' link. I tried a masonry bit but I didn't think to regrind it - and it just polished the bottom odf the hole. I've had one work in the past on a wheel stud,

I'm afraid I have done a disgusting bodge and turned each of the mounting holes into a slot with the angle grinder. the new part has holes on a triangle and the slots are such the screws won't be able to slip out. It ain't clever and it ain't pretty. But it's prettier than this example I found on t'web:

The god's have punished me with a stiff neck so I can hardly look up, down left or right! At least the dodgy handbrake (brake adjuster had slipped off the ratchet) was easy enough and remaining job is a brake pip, that for once appears to be wholly accessible once the ramps are at the back.

Neil

John (Bogstandard2) - I have a 3mm drill, about 20mm of it, stuck in a lump of ms which I would like to drill out - would your tuff drill do the business? Looked at carbide, but too much a case of "how much?"!

Chris

How soon do you need them Chris, if you can wait a week for delivery then Richon do cheap carbide drills. Their HSS and carbide milling cutters are also very good value for general day to day hobby use.

ChrisH Patience and a bit of cunning will get your drill out. Its lucky for you its such a large drill. 3mm luxury!

Can you pick up your block of MS

Start with a teeny hole and get it right

This relieves the big drill tip from cutting when you do the big hole and makes things easier

Jason, can wait a week or more, will look at Richon more closely

Old Al and Ady1, Patience and a bit of cunning is right - that is where the carbide drill comes in! 3mm was a starter drill for a 5.2mm dia tapping hole for M6, to me that was starting with a teeny hole! Makes me worried when I come to do make my model feed pump - 3mm is positively huge on that job. Have one of Arc's micro drilling devices for that, as have bought the required drills in ready and they're TINY! and Yes, the ms lump can be picked up, it was ¾ finish machined, which is why I want to drill the broken drill out.

Chris

Hello this is my first post.

I have just started the hobby after lurking around model exhibitions for several years . I have started with making the Tubal Cain Polly and am part way through Wenceslas from the same book. Using these small engines to relearn metal work and machining after leaving the engineering trade some 40+ years ago.

Back when I was an apprentice one of the jobs we were given was to remove broken taps and drills from nearly finished parts. This was done on a spark erosion machine. It was a bit like a mini arc welder where the spark would jump from the tip to the broken tool and slowly eat it away.

If you do a search for "spark eroder" on this forum there is some info plus a link to a company who offer a service. Just depends on how much they would charge against the cost of remaking the part.