Talk:List of drill and tap sizes

message: Fractions in this list use the format "​15⁄16" which, oddly enough, is a problem, as my keyboard (and those of nearly everyone else in the US) lack a "⁄" key - possessing, instead, the subtly different "/" key. It wasn't until I dug into the source that I understood why I couldn't do a ctrl-f search for anything involving (what appeared to be) a forward slash.
I don't want to take it upon myself to change them all (not knowing if there was a good reason they were made that way in the first place), but being this list used to be a frequent resource for me, and it's significantly less helpful without the ability to search.
(speaking of not knowing things, I have no clue what I'm doing with the new edit interface, and couldn't figure out how to create a new section without shoving it into an existing one. hopefully it won't break anything important)  - 71.234.116.22 (talk) 03:01, 27 May 2020 (UTC)
thread_title: Slash-Not-Slash Fractions?

message: I think the heading "Drill wire gauge" in the table may be incorrect. Surely gauge sizes for drills are not the same as American wire gauge? Biscuittin (talk) 13:23, 26 August 2009 (UTC)
replies: text: It's not saying that the drill bit gauges are exactly the same, it is just drawing an analogy to wire gauges. (The exact text is: "Number drill bit gauge sizes are analogous to, but different from, American wire gauge.") Wizard191 (talk) 20:41, 27 August 2009 (UTC)
replies: text: Number (and letter) drill bits are commonly referred to as "wire gauge" bits, although it's not even close. Pstemari (talk) 21:24, 25 November 2011 (UTC)
thread_title:  Number sizes 

message: If you are working in imperial, all measurements want to be the same.
Its pointless expressing the clearance hole for a 5/32" whitworth tap in millimtres!!! If you working in imperial, you primarily need to know the clearance drill is 5/32" and the tapping hole is 1/8". People who work in imperial do not work in imperial in one direction and metric the other.
You need two separate tables, one for metric in mm's  and one for imperial, in 64ths and thousands.
82.21.204.60 (talk) 13:34, 18 August 2011 (UTC)
replies: text: This is essentially the two separate tables in one table...with measurements in both mm and inches so they are easily compared. Coolhandscot (talk) 22:24, 19 August 2011 (UTC)

text: It's still a mess as is.  Getting the nearest US size for a metric size and vice versa is a useful purpose, but the organzation here doesn't make that easy. --Pstemari (talk) 07:04, 17 June 2012 (UTC)

text: Yes, being able to figure out the closest wire gauge drill bit for a metric tap is exactly why this table is so valuable to me.  I don't seem to have trouble with the organization, except that I lose track of the table columns while scrolling.  Any suggestion about how to improve the organization? Butchwax (talk) 15:36, 17 June 2012 (UTC)

text: Having 5 pages of microscopic drills at the top in 0.01 mm increments doesn't help. Perhaps slice out three additional tables:  one with UNC/UNF sizes, one with metric sizes, and a third that pairs up UNC/UNF with the nearest metric size and vice versa. Pstemari (talk) 04:36, 5 July 2012 (UTC)

text: The integrated table certainly is useful. Butchwax mentioned finding a number drill for an ISO thread. A mm drill for Unified or a Whitworth thread might also be required. Given that drill sets in 0.1 mm increments are readily available now, both number gauge and ISO drill sets are not necessary in a shop. Complaints against the integrated table can be answered by providing strictly Unified and strictly Whitworth tables separately. That should almost everyone. Regards, ... PeterEasthope (talk) 14:52, 16 July 2020 (UTC)

text: Forty rows is too many for at least one instance of headings on most screens. I've added four repetitions of the headings at intervals of 24 rows. Let's see how that is accepted. If most readers accept the arrangement, I can add more headings. This problem has been recognized but no automated solution is documented yet. Ref. Help_talk:Table#Sticky_table_headers?. A difficulty with repeated headings as I've done is that any change in heading will require multiple edits.  That is error prone. Automation of the sticky heading will solve that.  Regards, ... PeterEasthope (talk) 15:53, 16 July 2020 (UTC)
thread_title:  Complete rubbish 

message: I would find the table less confusing if the 4 colors were explained in a legend.
I wonder if Pstemari's objections would diminish if such a legend were up top and had checkboxes to hide/show the various subtables.  I believe this is rather easily doable in JavaScript, though I'm not familiar with Wikipedia ways to do it.  
Personally I like all the subtables (metric, imperial, gauge, etc.) interleaved into one combined table.  As Butchwax says it aids comparison. Bob Stein - VisiBone (talk) 01:33, 18 July 2012 (UTC)
replies: text: Forty rows is too many for at least one instance of headings on most screens. I've added four repetitions of the headings at intervals of 24 rows. Let's see how that is accepted. If most readers accept the arrangement, I can add more headings. This problem has been recognized but no automated solution is documented yet. Ref. Help_talk:Table#Sticky_table_headers?. A difficulty with repeated headings as I've done is that any change in heading will require multiple edits.  That is error prone. Automation of the sticky heading will solve that.  Regards, ... PeterEasthope (talk) 15:53, 16 July 2020 (UTC)
thread_title:  Unrubbish-ification 

message: I think the correct drill size for M6 should be 5.0 mm, I've always used a drill size that is the thread diameter minus the thread pitch.
That's what these tables specifies: http://www.newmantools.com/tapdrill.htm and http://www.shender4.com/metric_thread_chart.htm and http://www.engineershandbook.com/Tables/tapdrill.htm 
: Note that the link to engineers handbook dot com is broken .. the server no longer exists  — vulcan_ (talk contrib) 20:53, 10 April 2020 (UTC)
replies: text: The chart is mostly good, but it isn't great yet. The 5.2mm row does contain an error, although not quite the one you thought. A 5.2mm drill is indeed an acceptable tap drill for M6-1.0, and so is 5.0mm, *but* each yields a different percentage of thread (5.2→~60%, 5.0→~75%). So in the cell where that 5.2mm row now shows "75", it should say "60". One of the things going on in this chart, as of this writing, is that it shows only a one-to-one relationship of thread size to tap drill, when that relationship is actually one-to-several. Right now the chart doesn't reflect the fact that there are several acceptable tap drills for each thread size, with each giving a different percentage of thread between 60% to 75%. For example, for a 1/4-28 thread, any of these 3 tap drills may be acceptable: #3 (~75% thread), #2 (~60% thread), or 7/32 (~68% thread). In the case of M6-1.0, the rule of thumb that you mentioned, major minus pitch, yields a 5mm tap drill at ~75% thread. However, the tap drill that the chart mentions, 5.2mm, will give a ~60% thread, which is also acceptable, provided that a 60% thread is what the user wants. But the chart does have an error in that row, because it says "75" in the "percentage of thread column". It should say "60" there, and M6-1.0 should be entered also up above in the 5.0 drill row, with "75" as percentage of thread. I may edit the whole chart someday to reflect the one-to-several relationships, but it will depend on having a big chunk of free time with no higher priorities (story of life!). What I will do right now, though, is at least fix the two rows that we just talked about. — ¾-10 15:09, 18 November 2012 (UTC)
thread_title: Errors in M6

message: The entry for M4x0.70 shows only 1 entry, presumably for a "default" thread %, but it calls for metric 3.5 drill.  Every other chart I've ever seen calls for a 3.3mm drill for M4x0.70 tap.  This may be same as M6 example above, where entry in chart is actually a 60% thread, but it's claiming 75% and does not list the 75% thread drill bit size of 3.3mm.Bmeyette (talk) 17:26, 10 March 2014 (UTC)
replies: text: Added the M4 heading to help people following the multiple errors and corrections. Regards, ... PeterEasthope (talk) 15:05, 16 July 2020 (UTC)

text: hi , this will probably sound really stupid to you folks but I've been having difficulty figuring out what taps to use for my rc builds amd the screws are m4 and m3 I believe but I bought a 4-.70 tap and the m4 screws didn't work so I found an m4-40 and they worked but barely , I had to run the screws in and out like the tap to get them to finally go. I don't understand the huge difference in m4-40 and the 4-.70 either I thought they were both 4mm taps. Anyhow can you either direct me as to what taps I should use for 4mm machine screws and possibly a link to an actual complete chart with tap and screw sizes ? If one is available. My favorite part the rc hobby is building my own stuff as much as possible and being able to tap my own screw holes and maybe even make the odd threaded pieces would be an amazing addition to the endless number of skills to learn . Thanks and sorry for the long winded response , I try to get as much info in as I can and I tend to over explain myself lmao 🤣 😅 cheers Daveovington (talk) 03:44, 6 August 2023 (UTC)
thread_title: M4

message: This table is really useful, but hard to understand for someone unfamiliar with drills and taps. It would be really nice if the opening paragraph were expanded to explain what purpose of the table is, and what the columns mean.
The first two columns give diameters: diameters of what? What does "fractional" mean? What does "tap size" refer to?  — Preceding unsigned comment added by 129.215.138.131 (talk) 13:44, 17 June 2013 (UTC)
replies: text: I added some lede content that explains. HTH. — ¾-10 00:53, 18 June 2013 (UTC)
thread_title: Explanation

message: The metric screw tap and clearance sizes are largely missing, and those clearance hole sizes that are present are more often incorrect; e.g. M5 x 0.8 has 5.1 mm as close fit, but this would be an interference fit, all sources have 5.3 mm. (0.1 mm is below the sum of surface roughness and tolerance of the screw and clearance drill diameter.) (The source cited for the table - SmallParts.com no longer exists.
   The article should clarify that this is a tabulation of drill size recommendations including tolerances, not the precise minimum or maximum diameter of the required hole. 
   The following sources appear to be reliable based on a few entries, but have not been verified in detail;
https://littlemachineshop.com/Reference/TapDrillSizes.pdf
http://www.draughtsman.co.uk/information_images/mechanical/clearance_holes.htm
http://www.calculatoredge.com/charts/mmetricthreads.htm
    I am no longer current, but the chart most often seen on the wall in machine shops in the USA using imperial tooling was supplied by Starret. It looked like this recent version; https://forum.solidworks.com/servlet/JiveServlet/downloadBody/2791-102-1-3184/starrett-inch-metric-tap-drill.pdf  More complete information from the Starret catalog looked like this; http://www.jwdonchin.com/Starrett/Catalog/pdf/647.pdf
      As of this date both of these links are dead.  — vulcan_ (talk contrib) 19:43, 22 April 2021 (UTC)
thread_title:  Metric drill sizes for tap and clearance are missing, incorrect, thread % does not consider material 

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