JimAttrill Posted August 30, 2008 Share Posted August 30, 2008 You may all know about this but it was news to me.... We often get broken studs, especially TD5 exhaust manifold studs and rocker shaft bolts. These last are not easy to get out as they are 10.9 hardness. So we bought a 6mm Left-Hand twist drill. (I didn't even know they made such a thing). Used in a reversible air drill it has successfully removed three broken studs in the last week without using stud extractors. Just whizzes the stud out of the hole. Wasn't cheap though Quote Link to comment Share on other sites More sharing options...
BogMonster Posted August 30, 2008 Share Posted August 30, 2008 Never heard of such a thing either but it sounds like a good idea Quote Link to comment Share on other sites More sharing options...
kiall Posted August 30, 2008 Share Posted August 30, 2008 ive heard of them , quite good but mega expensive drills compared to normal ones Quote Link to comment Share on other sites More sharing options...
hoss1720 Posted August 30, 2008 Share Posted August 30, 2008 Snap -on do a kit ,nice,but expensive. I think you might be able to get one from an engineering tools supplier though. Quote Link to comment Share on other sites More sharing options...
TSD Posted August 30, 2008 Share Posted August 30, 2008 Snap -on do a kit ,nice,but expensive. Cheapish LH drills at Northern Tool http://www.northerntooluk.com/products.asp?partno=150272E Not exactly top quality, but that's not what you need. You aren't trying to dill a clean hole, and a drill that 'grabs' a bit helps to get the stud free. I wouldn't be without a set. Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted August 30, 2008 Author Share Posted August 30, 2008 Of course you need a reversible drill, which seems to mean it has to be an air drill, so you need a compressor, etc. Unless you can get reversible electric drills? Apart from hammer drills we prefer the air-driven stuff anyway. For the cost of the one 6mm LH drill bit we could have bought a complete set of 1-11mm drills! But it works so well we don't worry about the price. And being a workshop we will use it often. For a private owner it is an expensive option. That drill set from Northern Tools is incredibly cheap compared to what we had to pay. As you say, quality is not really required, it just has to grab backwards. You learn something new every day, and I have been in the engineering business since 1964 ha ha Quote Link to comment Share on other sites More sharing options...
smo Posted August 30, 2008 Share Posted August 30, 2008 Most battery hand drills are reversible as they can be used for screw driving as well Quote Link to comment Share on other sites More sharing options...
bluespanner Posted August 30, 2008 Share Posted August 30, 2008 I have a Snap-On stud extractor kit with the left hand bits. I rarely have to use the extractors, as i think the heat of the drill loosens it then winds it out by itself. Handy tools. Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted September 1, 2008 Share Posted September 1, 2008 Most battery hand drills are reversible as they can be used for screw driving as well As do a lot of mains powered drills these days. The Bosch I bought a couple of weeks ago is reversible (and a very nice drill - I think Screw Fix still have them on special offer for about £55). Quote Link to comment Share on other sites More sharing options...
TSD Posted September 2, 2008 Share Posted September 2, 2008 That drill set from Northern Tools is incredibly cheap compared to what we had to pay. As you say, quality is not really required, it just has to grab backwards. You learn something new every day, and I have been in the engineering business since 1964 ha ha I keep a set in my (electronics) toolbox for work. Lots of stainless M3 pozis that always get the heads chewed off by clumsy assemblers. Won't tell the clients where I got them though. As the old joke goes...$1 for the chalk mark, $19999 for knowing where to put it Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted September 2, 2008 Author Share Posted September 2, 2008 In a discussion with my colleague we came to the conclusion that removing broken studs is the only use for LH drills. Unless you need Left handed holes Quote Link to comment Share on other sites More sharing options...
Warthog Posted September 2, 2008 Share Posted September 2, 2008 In a discussion with my colleague we came to the conclusion that removing broken studs is the only use for LH drills. Unless you need Left handed holes Left-hand drills used in the repetition engineering industry on screw machines or drilling heads. Left-handed drills allow a machining operation to continue when the spindle either cannot be reversed or where the design of the machine makes it more efficient to run left-handed. With the increased use of the more versatile CNC machines their usage is less common than when specialised machines were required for machining tasks. Also very good to give to Apprentice's Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted September 2, 2008 Author Share Posted September 2, 2008 Hi Warthog, my mate and I agreed on the two reasons you put forward above. I don't know much about automatic lathes but did think that maybe they might sometimes need a left hand drill. And as for fooling apprentices: "here sonny drill these 20 holes before lunchtime" When I was apprentice I was sent for 'a long wait' at the stores. I came back 1 min before knocking off time. That taught 'em Quote Link to comment Share on other sites More sharing options...
calle-fas Posted September 9, 2008 Share Posted September 9, 2008 For smaller studs torx bits are quite good if you only have RH drills. They are cheap too. Quote Link to comment Share on other sites More sharing options...
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