Forums DIY and Mods Inches to mm drillbits? Viewing 12 posts - 1 through 12 (of 12 total) Author Posts April 4, 2012 at 1:48 pm #576738 Bjorgvin 74 Posts I have a voile diy kit. The tool list shows drill bit and wood paddle bits in inches I think. Are there a direct mm convertion? Or do I need to source down some new drillbits? Thanx April 4, 2012 at 2:03 pm #654527 singlewhitecaveman 242 Posts You can usually get it pretty close with metric sizing. I don’t recall there being any holes in the DIY convrsion that require total precision. Jsut make sure you get the puck spacing correct! April 4, 2012 at 2:13 pm #654528 PedroDelfuego 758 Posts Try to find a Forstner bit if you can, they work better than paddle bits…. April 4, 2012 at 6:42 pm #654529 Bjorgvin 74 Posts Thanx for the frostner bit tip! Anyone willing to take a shot at converting this to the closest metric? Drill Bits: 1/8”, 3/16”, 19/64” 3/4” Wood Paddle Bit 3/8” Countersink Bit 3/8” Nut Driver April 4, 2012 at 9:26 pm #654530 BobGnarly 220 Posts 1/8= 3.175mm 3/16= 4.7625mm 19/64= 7.540mm 3/4= 19.05mm 3/8= 9.525mm 1″ is 25.4mm April 5, 2012 at 8:36 am #654531 g_torphins 109 Posts I used a 7.5mm bit for all the T-bolt holes, a 20mm router type bit for countersinking on the base and a 5mm bit for the nose/tail clips and hooks. Used these bits for two boards with everything working out perfectly……….so far 😆 Hope that’s of some help George April 5, 2012 at 10:06 am #654532 Bjorgvin 74 Posts Big help guys! I knew the inch to mm was 25,4. But i’m lost when there is a slash in between 😀 April 5, 2012 at 10:13 am #654533 BobGnarly 220 Posts To work it out do this. Say you need 3/64″ this is the formula. 25.4 divided by 64 =0.396875. 0.396875 x 3 = 1.190625 So divide 25.4 by the second number, then multiply by the first number. April 5, 2012 at 3:20 pm #654534 aliasptr 282 Posts I use Google for just about all my conversions. It’s a pretty flexible calculator which also includes many useful physical constants. So for 3/8″ to mm you can do: https://www.google.com/search?q=%283%2F8+inches%29+to+mm&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a You can do much more sophisticated calculations too just be sure to go heavy on the parenthesis. So another fun one is the average cost of driving your car per mile. So I calculate average gas mileage and then the cost per gallon of fuel: https://www.google.com/search?q=%28320+miles%29%2F%2812+gallons%29*%281+gallon%29%2F%284.04+USD%29+in+%28miles%2FUSD%29&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a Here’s a short guide to it: http://www.googleguide.com/help/calculator.html and a bit longer: http://www.googleguide.com/calculator.html Hope this helps! April 5, 2012 at 3:22 pm #654535 Bjorgvin 74 Posts Thanx again! I am stoked with the will to help! :headbang: I have the drillbits I need, and I found a bit that looks like the frostner bit. Says on the description that it does leave a clean and exact hole… Cost just a few bucks. So the only piece I am missing is the countersink bit. When googling it, it looks like it has a pointy edge. Why cant I just use a normal wood drill bit? Just go a bit down so the allen head of the chinese hook bolts are sunk in? Doesnt look like the countersink bit will leave a flat surface? April 5, 2012 at 3:29 pm #654536 aliasptr 282 Posts A countersink bit drills the correct angle for a flat head screw to seat into. A normal twist drill bit has a different angle and you will find that the flat head screw will not seat correctly. Here’s an image example of what I mean exactly and here’s a short summary on screw head types. http://www.eaglefastener.net/technical/screw-head-styles.html Hope this helps! April 5, 2012 at 3:34 pm #654537 g_torphins 109 Posts ^^^Nice info!! This is the bit I used It works pretty well, just watch how deep you go!!Remember the T-Bolt will sink in to the core very slightly. George Viewing 12 posts - 1 through 12 (of 12 total) You must be logged in to reply to this topic.