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Marv...I don't know 'buchstaubiern'. That seems to translate to 'paper jam beers'?Swapping the 'i' and 'e' gets me 'paper dust Irish'.
Karl (lassen wir richtig buchstaubieren),Yes, you need to watch what you're doing and move the quill down when the tap wrench is about to escape from the guide pin. I have a tap wrench like yours and find it way too heavy for small taps. For those you need something with low inertia so you don't lose your tactile feel for what the tap is doing. With my small tap holders I can always feel when I've outrun the guide pin.Jim,There's a program on my page, DRILL, which will compute tap drill sizes for conventional and form taps as well as other good stuff. But, briefly, TD = tapdrill sizeMD = thread major diameterP = thread pitch (tpi)DOT = desired depth of thread expressed as a percentagethenTD = MD = 0.013*DOT/PExample: 1/4-20 thread with DOT = 55%TD = 0.25 - 0.013*55/20 = 0.2143 which implies a #3 drillHere are some suggested DOTs for various materialsMILD AND UNTREATED STEELS 60-65HIGH CARBON STEEL 50HIGH SPEED STEEL 55STAINLESS STEEL 50FREE CUTTING STAINLESS STEEL 60CAST IRON 70-75WROUGHT ALUMINUM 65CAST ALUMINUM 75WROUGHT COPPER 60FREE CUTTING YELLOW BRASS 70DRAWN BRASS 65MANGANESE BRONZE 55MONEL METAL 55-60NICKEL SILVER (GERMAN SILVER) 50-60Stan,Love it. Trouble is, if Starrett sold crayons, they'd cost $20 apiece. Mitutoyo crayons would cost $1 and last three times as long.