<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style></style></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1>I’ve done a couple of hundred? Pinblocks over many years.  Naturally, I have formed some ideas as to what works best.  I am not a fan of brad points, they don’t seem to stay sharp as long and don’t clear chips well.  For very many years, I have used good quality fast spiral drill bits because they clear chips the best.  About 1100 RPM, feet at a steady rate, but do not hog.  Feed rate is a developed feel, like porridge.  Not too fast, not too slow – just right.  Compressor hose clears chips and keeps the bit cooler.  Use the shortest bit that will be long enough to drill the block, less likely to bend as it seeks the index mark.  <o:p></o:p><o:p> </o:p>As for the proper size, buy all 3.  The missing link here is the how much or how little run out you have on your drill press – that will have an effect on the diameter of the finished hole and will determine what size will work best for you.   The length of tuning pin and how much of the thread is in the block itself will also determine how much purchase the pin has on the block. <o:p></o:p><o:p> </o:p>Also, the recommended sizes as shown in the Pianotek catalog are for 2/0 pins, which are .282 (sort of), while 1/0 pins are .276 (sort of).  You may find that if you drill for 2/0 pins and use a 1/0 pin, your block may well be too loose.  Use 2/0 pins unless there is some compelling reason to use the smaller pin.<o:p></o:p><o:p> </o:p>You will have left over stock after you make the block.  I keep mine and do several test drillings.  I drive in tuning pins to the same depth and decide which I like the best, which you can do by feel.  <o:p></o:p><o:p> </o:p>Will Truitt<o:p></o:p><o:p> </o:p>From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Noah Frere Sent: Wednesday, March 06, 2013 2:57 PM To: pianotech@ptg.org Subject: [pianotech] Size of Pinblock Drill bit?<o:p></o:p><o:p> </o:p><div>I searched my not inconsiderable archives for an answer, but have come up empty-handed. I am using 1/0 Denro blued tuning pins in a new multi-lam Maple pinblock, and need to order the drill bit. I'd like to double-drill - makes sense. The Pianotek catalog recommends, in effect, a drill bit .016" to .021" under the diameter of a 2/0 pin in a multi-lam pinblock. Following that logic, I could use the .250" on the first pass, and the .261" (.015" under) or .257" (.019" under) drill bit on the second pass. Also, I like the idea of the brad-points, but also like the idea of the other ones, which are "slow spiral."  Any recommendations?<o:p></o:p></div></div></body></html>