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Huge problem involving invincible materials Answered

Ok I'm making a few projects and the cutoff for one of them (the bottom end of a bullet shell casing) is a perfect piece in the puzzle for another, i need a hole drill through it, so I got the drill of doom out and the apparent uber go through anything drill bits and the metal ones, I went to drill in to the bottom of this using the firing pin impression as a starter guide (it was dead centre) And at first I thought this was all going smoothly, and as I spun the drill up to full speed there was plenty of metal shavings coming out, I stopped for a look because a bit of distance had went by and there was a tiny dent in the subject, the drill bit however was noticeably shorter than before... the same bits as the ones we use for drilling out flint tubes in antique lighters, they're tough (it was bigger bit in this case but same type) so I tried the bog standard metal work bit it made no difference to the hole and was shredded away similarly. First of all what the hell is that striker made of and second of all what the hell drill bit can get through it, I knew they were tough, I couldn't be assed cutting one with just a hacksaw blade so i did it with the drill as a lathe...

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Tool Using Animal (author)2008-01-21

Shell casings are generally made either of steel or brass, the anvil is formed during the forming of the case, so it's of the same material. The anvil is work hardened during forming so you can anneal it with a blow torch. If it's a brass case heat it until it changes color and let cool, if steel heat it until it starts to glow and let cool. If it's a brass cartridge you can also resharpen your drill bit with a zero rake angle to help keep the drillbit ffom grabbing when you do get through.

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gmoon (author)Tool Using Animal2008-01-21

as I spun the drill up to full speed

Adding to the above--drill slowly in metal (and add a bit of lubricant.)

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Goodhart (author)gmoon2008-01-21

agreed. But if the bit spiraled off shavings in the same manner as the hole were being cut, then the bit itself might have been used too often on metal without proper cooling/lubrication, i.e. it might have been softer then it should have been. *shrug*

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killerjackalope (author)Goodhart2008-01-21

i suppose it could have been during some work done with it, I think I may have done enough to knock the pin out, after that there's two holes that wile suffice also working on drill powered lathe, got some stuff ready for that, but the frame is complicated, I would use wood but that wouldn't live all that long for the frame design, unless I use the bench as a mounting frame...

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Goodhart (author)killerjackalope2008-01-21

:-) I still have one of these in the back room somewhere: And I think I have seen a cheapo version of something they sell that holds a hand drill in place with a set of gears to lower it like a regular drill press (the one in the picture descends very VERY slowly)

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user

That's awesome goodheart, I'll give you ten bucks for it, and I'll tell you what I'm gonna do, I'll even let you pay shipping because I like your face.

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user

Your handcranked drill press, I was making an offer.

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Oh I see. Well that one in the picture is not mine. I never took a picture of mine (it's not painted like that one is, and I don't even know how much I paid for it years ago at an auction). The postage for that mass of iron would be substantial :-)

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Goodhart (author)Goodhart2008-01-21

I had a old 'smithy's "axial" sledge years ago too. Back when I could swing a 24 lb sledge over my head a few times. LOL

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killerjackalope (author)Goodhart2008-01-21

Nah drill press isn't a problem, jsut controlled by hand rather than a lowering mechanism but my lathe plan is to make a mini lathe with a plug and play design for powering it from a drill. I'm thinking of using some derelict bike as drive and to bring the speed up slightly to about 5,000rpm maximum, not sure whether it should clamp the piece in hand via two clamps of by a pressure holding system using two screw out clamps to hold the piece, both have their limitations, the squeezing one would mean working lightly but if you caught a big burr you wouldn't lose your hand, the other has more strength but balancing issues. I love the old drill press there, I have a bench clamp that would match it really well.

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killerjackalope (author)gmoon2008-01-21

Not full speed but the most I would use to go on metal, though I could have used a little less torque by using a high speed setting and been leaner on the trigger, that said at one point I considered going full speed to see what happened...

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Ah damnit I always thought the anvil was seperate, only my blowtorch is out of action, do you think 1300oC would break the annealing lol jet lighter gets another boost for a while, it's hot enough but needs to produce more heat or I'll be here all day... ok took about a minute of full force to annhialite most of the boddy but the striker held up despite also being brass, also my pliers appear to have stuck themselves on because there were metal shaving in between the teeth...

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500-600 C is plenty hot enough. so your lighter should/might work.

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will only the rest of the casing keeps acting as a heatsink and the whole thing is charred, on the upside the burrs from lathing have been destroyed completely by the process...

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there's a thing called moderation ;-) An old trick used by reloaders when they anneal the case neck is to submerge all but the neck in water, then apply heat.

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Peice is a bit too small for that, thankfully the seal is breaking up due to heat I may be able to do it, I'll have to set up my torch made from scavenged jet lighter parts and get it going, It's more powerful and much easier to work with. Also I may make my own torch from scratch soon, the design is dead simple and the portable stove (derelict) would make a good base for the project as the plumbings all there and it can take different size canisters so the gas can be changed...

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