Announcement

Collapse
No announcement yet.

Metric Drill Bits

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Metric Drill Bits

    How many of you have sets of metric drill bits, do you find you use them on a regular basis, and where did you get them? The reason I asked is that when I got a new DRO for the mill of course all the fasteners are metric. Being somewhat stuck in fractional measurements I don't have many metric drill bits. I have all the fractionals up to 1 1/2" and the letters and numbers, but never found much of a need for a metric set. Metric fasteners aren't new to me. In fact I have several sets of metric taps & dies. However even the metric taps I have call out fractional hole sizes.


    I've looked at Enco,and all the the "discount" tool houses and none seem to have very much to offer. About the most complete sets I've seen are at MSC, and they seem a bit pricey. So the question remains is it worth it to buy a set of metric bits? For general purposes it seems there are fractional, letter and number drills within .0001 or so of the most popular metric sizes. Is it finally time to move into the 21st century?

  • #2
    I've considered getting some in the past, mostly to fill in small incremental diameters between the drills in the sets of number, fractional and letter drills I already own. So far I haven't really had the need to get them though so I haven't done it. It's on my list I guess but when I buy drills I buy quality, not the cheapo Chicom stuff and the money spent on drills I may never need can be spent on things I'd use more often. I find that I use my fractional drills most, followed by number and then letter drills.

    Comment


    • #3
      If you already have all of the fractional drills, plus number and letter drills, then you've got 95% of the field covered.
      Most metric drills only differ by a few thousandths, so getting a complete set is kinda pointless.
      You can always 'round up' to the nearest drill size for drilling thru-holes or tap holes.

      Comment


      • #4
        Ditto with KZH, standard 115 drill set will pretty closely cover metric sizes in reasonable size holes above 2mm. Below that it is hard to be precise but the variations become 0.002 or less difference
        one drill to the next. Enco took a flyer in 2009 with a 115 or so drill set in a nice box with 0.05mm delta 1.6mm to 2.4mm then 0.1mm delta size from 2.5 upto 13mm drill set for $122. Don't recall
        source but not stamped chinese and the box is much better grade than the chinese boxes I have seen for the inch sets. Metallurgy seems ok for the ones I have used. However the offer was never
        repeated and there has been nothing similar in the catalog since. This sort of set is readily available in Europe.
        Steve

        Comment


        • #5
          I don't know what kind of work you are doing, but if you are doing metric work and you don't mind having to constantly convert and than check three different drill sets for the best match -
          than you have enough drills to do the job. Tip for your metric taps : To find the correct tap drill just subtract the pitch from the nominal size. M6, pitch 1mm, 6-1=5mm tap drill, M10, pitch 1.5mm, 10 - 1.5 = 8.5mm tap drill. So for a 5mm tap drill (5/25.4 = 0.197) a #8 drill would be your best choice. For a 8.5mm tap drill (8.5/25.4 = 0.335) a letter "R" would be OK.

          Comment


          • #6
            Metric drill sets can be a problem as the usual range is in 0.5mm (~0.02") increments which are larger than the normal inch set increments (1/64" ~ 0.016"). I usually use my "inch" sets as it can matter for tapping drills for the smaller metric tapping jobs (say M4 and downwards).

            Most tapping drill tables have alternative drill sizes as well.

            Comment


            • #7
              I just get mine from "KBC". (KBC.com - although I use the canadian site)

              With few exceptions, all of my fractional, number, letter drills have not seen the light of day in a decade or two.

              So, metric drill sets can replace all of the above. I have sets 1mm - 5.9mm, by 0.1mm, and 1mm to 13mm by 0.5mm. (6.35mm = 1/4 inch, 12.7mm = 1/2 inch)


              (I still have some long drills in fractions, and small number drills 61-80, but all of these I don't use more than once or twice in a year)

              Another JohnS.

              Comment


              • #8
                Originally posted by oldtiffie View Post
                Metric drill sets can be a problem as the usual range is in 0.5mm (~0.02") increments which are larger than the normal inch set increments (1/64" ~ 0.016"). I usually use my "inch" sets as it can matter for tapping drills for the smaller metric tapping jobs (say M4 and downwards).
                Sorry, but metric drills are readily available in 0.1 mm or even in 0.05 mm increments. The usual "drill set" goes from 1 - 13 mm with 0.5 mm increments and the usual addons to that are the tapping sizes 2.5, 3.3, 4.2, 6.8, 8.5 and 10.2 (M3 - M12). And usually the 0.1 mm incremented sets come in 0-6 mm range and 6-10 mm range.

                However, it is very rare that you would need anything but the 0.5 mm increments and tapping sizes.
                Amount of experience is in direct proportion to the value of broken equipment.

                Comment


                • #9
                  Originally posted by Jaakko Fagerlund View Post
                  Sorry, but metric drills are readily available in 0.1 mm or even in 0.05 mm increments. .
                  Not common in Australia.

                  Comment


                  • #10
                    Originally posted by TR View Post
                    Not common in Australia.
                    I know that people say NZ is like living 30 years behind the times, but I thought the Aussies might be a bit more with it
                    Been very common over here for as long as I remember.

                    Comment


                    • #11
                      I have Fraction/number/Letter/and Metric, and use all.
                      I see no differences in threads. As comfortable with Metric as I am with USA, BA or non-standard pitches .
                      If you work with doing odd jobs, that is, repairing all manner of threads, then there are not enough drill sizes in the world.
                      Case in point, (didn't need a drill however) my friend brought me a 1800's antique to fix as it had a single 5/16-24 (.312)screw that was stripped, as was the hole.Putting a new 5/16 screw in was very marginal so I used a .324-32 tap I had and made a new screw for him.
                      If you work building new stuff, then having lots of drills is not needed IMHO.

                      Rich

                      Comment


                      • #12
                        Originally Posted by Jaakko Fagerlund

                        Sorry, but metric drills are readily available in 0.1 mm or even in 0.05 mm increments. .

                        Originally posted by TR View Post
                        Not common in Australia.
                        Yes they are - any amount of tool suppliers - one example:

                        http://www.machineryhouse.com.au/Drill-Jobber-Sets

                        Comment


                        • #13
                          The availability only depends on where you look , I have managed to obtain two sets from engineering supply businesses off the shelf.
                          Local hardware are way over priced, like most things ,have a good look around the better suppliers.
                          Most professional workshop suppliers have had them on the shelf for years.
                          I dont buy in ones and twos , usually a packet of ten of the most commonly used sizes.
                          Michael

                          Comment


                          • #14
                            Thanks.

                            Comment


                            • #15
                              Metric drills yes; for everything metric - printers, cars, computers

                              Canadian tire used to sell Dormer/SKF

                              Comment

                              Working...
                              X