Electronics World Cover,TOC,and list of posted Popular Electronics articles QST Radio & TV News Radio-Craft Radio-Electronics Short Wave Craft Wireless World About RF Cafe RF Cafe Homepage RF Cafe in Morse Code Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs Twitter LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes AN/MPN-14 Radar 5CCG Notable Quotes App Notes Calculators Education Magazines Software,T-Shirts,Coffee Mugs Articles - submitted by RF Cafe visitors Simulators Technical Writings RF Cafe Archives Test Notes RF Cascade Workbook RF Stencils for Visio Shapes for Word Thank you for visiting RF Cafe!

SAE Tap & Drill Chart

The twist drill bit was invented by Steven A. Morse of East Bridgewater, MA, in 1861. He received U.S. Patent 38,119 for his invention on April 7, 1863. The original method of manufacture was to cut two grooves in opposite sides of a round bar, then to twist the bar to produce the helical flutes. This gave the tool its name.

Nowadays, the drill bit is usually made by rotating the bar while moving it past a grinding wheel to cut the flutes in the same manner as cutting helical gears. Tools recognizable as twist drill bits are currently produced in diameters covering a range from 0.05 mm (0.002") to 100 mm (4"). Lengths up to about 1000 mm (39") are available for use in powered hand tools.

The geometry and sharpening of the cutting edges is crucial to the performance of the bit. Users often throw away small bits that become blunt, and replace them with new bits, because they are inexpensive and sharpening them well is difficult. For larger bits, special grinding jigs are available. A special tool grinder is available for sharpening or reshaping cutting surfaces on twist drills to optimize the drill for a particular material. -Wikipedia

Standard SAE (Society of Automotive Engineers) tap & drill size chart.

Thread
Size
Drill
Diameter
(in)
Tap Drill
Size
  Thread
Size
Drill
Diameter
(in)
Tap Drill
Size
Coarse Thread Fine Thread
1-64 .0595 No. 53 0-80 .0469 3/64
2-56 .0700 No. 50 1-72 .0595 No. 53
3-48 .0785 No. 47 2-64 .0700 No. 50
4-40 .0890 No. 43 3-56 .0820 No. 45
5-40 .1015 No. 38 4-48 .0935 No. 42
6-32 .1065 No. 36 5-44 .1040 No. 37
8-32 .1360 No. 29 6-40 .1130 No. 33
10-24 .1495 No. 25 8-36 .1360 No. 29
12-24 .1770 No. 16 10-32 .1590 No. 21
1/4-20 .2010 No. 7 12-28 .1820 No. 14
5/16-18 .2570 'F' 1/4-28 .2130 No. 3
3/8-16 .3125 5/16 5/16-24 .2720 'I'
7/16-14 .3680 'U' 3/8-24 .3320 'Q'
1/2-13 .4219 27/64 7/16-20 .3906 25/64
9/16-12 .4844 31/64 1/2-20 .4531 29/64
5/8-11 .5312 17/32 9/16-18 .5156 33/64
3/4-10 .6562 21/32 5/8-18 .5781 37/64
7/8-9 .7656 49/64 3/4-16 .6875 11/16
1"-8 .8750 7/8 7/8-14 .8125 13/16
  1"-14 .9375 59/64

Try Using SEARCH to Find What You Need.  >10,000 Pages Indexed on RF Cafe !

Copyright 1996 - 2016
Webmaster:  Kirt Blattenberger, BSEE - KB3UON
Family Websites:  Airplanes and Rockets | Equine Kingdom

All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.