Actually, I spend probably about US$9 a year on the stuff for the workshop. I use it as way-oil, general lube and rust protectant. It's clean, doesn't smell, works *very* well and a little goes a long way.
I once made the mistake of using regular mineral motor oil instead -- what a stink -- it took days to come out of my hands.
Yep. I had one unspiral itself when I tried to drill with it. Thinking it was an isolated fault, I returned it to the supplier and the same thing happened with the replacement and with the replacement for the replacement, even though the supplier, a respected specialist supplier of drills to the engineering trade, assured me that they were all from different batches.
As I mostly use automatic machinery, I prefer solid carbide for stainless.
A lot depends on the hole size, and the rigidity of your drill press / hand drill.
If you try to drill 13mm straight off with a hand drill, then there's the potential for so a slight difference in cut depth from side to side turning into a considerable off-axis force. The hole is likely to wander like crazy, possibly with injury.
If you're drilling on a rigid drill press, then even then you can have problems with thin sheet (and I mean
Not really -- use WD40 instead or, failing that, water applied from a hand spray. Even if the water doesn't lubricate the drill bit, it will at least help to keep it tolerably cool.
I must admit that, whilst I've not tried it as a drilling coolant or lubricant, I have used "I Can't Believe It's Not Butter" [1] when turning stainless steel; it seemed to work reasonably well, though the workshop stank like a chip shop for days afterwards.
[1] I'd bought two tubs in a B.O.G.O.F. supermarket promotion and, on tasting it, I soon decided I'd been overcharged on both. There again, I'd doubt that anyone could pay me enough to *eat* the stuff...
IIRC, those "Piranha" drills are impossible to regrind to the same profile and may have too thick a web for a conventional re-grind.
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or, to download (18Mb),
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Except that, by then, the final hole may have wandered a little from where you'd like it to be.
The cutting point of a twist drill is meant to be the "chisel edge"; by drilling a pilot hole, you're making the drill cut on the flutes rather than the chisel edge and therefore the drill will faithfully follow the pilot hole. However, as the smaller drill is thinner, it is also more flexible and may have deformed or deflected as it was fed into the work- piece. Yes, it's a lot easier to drill one or more pilot holes, but it may not be as accurate as drilling with the "right" size of drill.
But then, if one really wanted accuracy, one would drill slightly undersize and then ream out the hole to the final diameter...
buy a pillar drill. Get some good quality metal drills, I bought a set from machine mart for about £30, sizes from 1mm to 13mm. Skimping on equipment will get you nowhere.
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