Talk:Drill bit sizes

Hmm, are Long series drills a size or a type? The addition of Gun drills spotlights the question further. I'll move Gundrills to Drill bit, and copy Long series drills there also. -- Graibeard 08:14, 28 August 2005 (UTC)

Decimal-fraction equivalents: 0 to 1 by 64ths
This table is way too big, disrupts the page. Fix it, anyone? Greetings, --Janke | Talk 07:34, 6 April 2008 (UTC)


 * Fixed. Broke it out into its own separate "List of" article, called List of decimal-fraction equivalents: 0 to 1 by 64ths. — ¾-10 21:07, 6 April 2008 (UTC)
 * I have proposed that the List of decimal-fraction equivalents: 0 to 1 by 64ths is deleted. Reasoning on the talk page. GameKeeper (talk)

jobber length text is bonk
Text on current page, section 6 is: Jobber-length drill

Jobber-length drills are the most common type of drill. The length of the flutes is between nine and fourteen times the diameter of the drill, depending on the drill size. So a 1⁄2 in (12.7 mm) diameter drill will be able to drill a hole 4 1⁄2 in (114.3 mm) deep since it is nine times the diameter in length. A 1⁄8 in (3.2 mm) diameter drill can drill a hole 1 5⁄8 in (41.3 mm) deep since it is thirteen times the diameter in flute length[citation needed]

Replace 'jobber' with the word 'standard' in both the heading and the text above. New paragraph below.

jobber-lenght drill==

Jobber-lenght drills, or just "jobber drills" are longer than standard and have longer groves extending the depth of the hole possible.

When the author wrote "most common ...", that would be the standard set one would buy, where each larger size is a little longer than the one before, and a set would range from 2 to maybe 4 inches long. I should/shall do some measurements, but the diameter vs how deep a hole (based on the spiral cut) makes sense.

In NJ and PA, Jobber bits or jobber-length-bits are longer, or much longer than standard and permit a deeper hole than the standard bits.

CliffOnTheRoadCliffontheroad (talk) 06:11, 31 May 2016 (UTC)

November 2016 modified text for Jobber Bits. Since there was no "standard size" paragraph, I changed 'common' to 'not common' in the 'jobber bits' paragraph. Citation? My Dad and "common knowledge" I did not check the figures on 'grove length' of standard nor jobber bits, but visually, both have the same length of 'no groves' where it is placed in the chuck. BTW, a 'aircraft lenght' bit has a long shaft with groves only on the last inch or three. Cliffontheroad (talk) 05:38, 24 November 2016 (UTC)

Metric drill bit sizes is incomprehensible by humans
There is a microscopic dot, which apparently means multiplication.

At least give a couple of examples. Even better, list them all! — Preceding unsigned comment added by 73.170.167.183 (talk) 23:18, 25 June 2018 (UTC)

Is the table missing UK drill number sizes?
The number sizes quoted may be applicable to the US, but historically in the UK screw and drill sizes, when quoted using a number scale, increased with increasing number - so a No. 4 drill (or screw) would be small, and a number 8 would be larger. Exmples (approximate dimensions, for masonry drills: 6 - about 4mm, No. 8 about 3/16 inch or 4.5mm, No.9 about 5mm, No.10 about 5.5mm etc.

I cannot find any discussion of this scheme for giving the sizes of drills but it should at least be mentioned as a historical system, in use at least until the 1990s.

Thank you. Alan Curtis81.151.16.193 (talk) 22:32, 12 June 2021 (UTC)
 * I believe that you are confusing wood screw gauge sizes and the number drill series. The latter I believe originated in the UK but has in the UK largely been superseded by the metric system while it is still in use in the US. Both the US and the UK use/used wood screw gauges which increase numerically with size, I have no idea whether they use the same scale but both are unrelated to the number drill series which is the subject of this topic. Clivel 0 (talk) 23:13, 12 June 2021 (UTC)