Tapping Drill Sizes. min. (EXAMPLE 1/4-20 Tap with 65% Thread) = . BA Threads Tap and Drills Sizes . We will continue to supply the ongoing demand for the old standard miniature screw threads. Tools recognizable as twist drill bits are currently produced in diameters covering a range from 0.05 mm (0.002") to 100 mm (4"). eg. A screw size number corresponds to a diameter … NEF NS Tap drill for NS Nut Size ½″ 0.5000 ½″ Gage and Fractional Sizes Clearance Drill NC tpi Tap Drill for NC NF tpi Tap Drill for NF M24 x 1.5 In the chart, you simply find the number … Class Minor Dia D1 min. threads (inches) The pitch is 1/16". Lengths up to about 1000 mm (39") are available for use in powered hand tools. 1. For the current series, see Unified. Engineering ANSI Hardware Design Data Engineering Metric Hardware Design Data. Thread percentage : (77% thread is what you want to use) A 100% thread is 3/4 qtr , or (6/8 th ), of the full 60° triangle which is the maximum allowed height of a full thread, the "V" shape, including flats. Machinist Metric ISO Screw Thread Tap - Drill Size Chart. For Imperial (inch) threads the tapping drill size is calculated in the same way, diameter minus pitch. The second number is the UNF (Unified National Fine) pitch. M10 x 0.75. In contrast to straight threads that are found on a bolt, a taper thread will pull tight and therefore make a fluid … - reaming of the hole may PRACTICAL FORMULA - INCH SIZES TO ESTABLISH TAP DRILL SIZES FOR INCH SIZE ROLL FORMING TAPS TAP DRIIL SIZE = Basic Tap 0.0. An ideal tap drill should be of 85% of the major diameter of the coarse thread you are working on. When you want to find the right sized drill and tap size, you also need to know if the screws that you will be using are fine or coarse. Fractional sizes are listed in inches, metric sizes are listed in millimeters following the letter "M". THREAD/SCREW - Drill & Tap Chart . where is the tap drill size, is the major diameter of the tap (e.g., 10 mm for a M10×1.5 tap), and pitch is the pitch of the thread (1.5 mm in the case of a standard M10 tap) and so the correct drill size is 8.5 mm. A screw size number corresponds to a diameter which is larger for a higher screw size. min. Drill sizes: Taper Pipe Tap* C: Q: 7/16: 9/16: 45/64: 29/32: 1-9/64: 1-31/64: 1-23/32: 2-3/16: 2-5/8: 3-1/4: 3-3/4: 4-1/4: Straight Pipe Tap** 1/4: 11/32: 7/16: 37/64: 23/32: 59/64: 1-5/32: 1-1/2: 1-3/4: 2-7/32: 2-21/32 *Sizes given permit direct tapping without reaming the hole, but only give a full thread for the first two or three threads. M6 x 1 6 - 1 = 5mm and you thought metric was difficult ;-) Thanks to Jay Steinbuchel of Barksdale Control Products for the following: This works for all 75% threads, not just metric. Screw Size Specifications Tap Drill Clearance Drill Aluminum, Brass & Plastics Steel, Stainless Steel & Iron Close Fit Standard Fit 75% Thread 50% Thread … Inch/MetrIc tap DrIll SIzeS & DecIMal equIvalentS Bulletin 1214-5M/S 05/10 starrett.com pipe tHreaD SizeS (npSc) tHreaD Drill tHreaD Drill 1/8 – 27 11/32 11/2 – 111/2 13/4 1/4 – 18 7/16 2 – 111/2 27/32 3/8 – 18 37/64 21/2 – 8 221/32 1/2 – 14 23/32 3 – 8 31/4 3/4 – 14 59/64 31/2 – 8 33/4 1 – 111/2 15/32 4 – 8 41/4 11/4 – 111/2 11/2. ©2013 American Fastener Technologies Corporation 9 Frontier Drive, Gibsonia, PA 15044 - 7999 U.S.A. 724-444-6940 National Pipe Thread Taper ( NPT ) is a U.S. standard for tapered threads used on threaded pipes and fittings . min. Helicoil Tapping Data - Metric: Heli-Coil taps in various types and styles produce holes for Tolerance Classes 4H5H or 3B and 5H or 2B for use in the general range of aluminums, magnesiums, mild steels, free machining stainless steels and other free machining materials. Machine Screw and Drill Size Chart (English) Clearance Hole Drills Screw Designation Tap Drill Size Close Fit Loose Fit Number Diameter Pitch Tap Size Drill Diameter Drill Diameter Drill Diameter or dia. Tap Drill 0.25 … ISO Metric profile External (bolt thread) Internal (nut thread) Basic mm Size mm Thread Designation Simple Thread Designation Pitch mm Class Major Dia d=D max. TAP DRILL SIZES INCH / METRIC EQUIVALENT Thread Size Tap Drill Size Thread Size Tap Drill Size Cut Thread Form Thread Inch Metric Cut Thread Form Thread Inch Metric #0-80 0.0472 1.20 M10x0.75 0.3622 9.20 #0-80 0.0551 1.40 M10 0.3681 9.35 #1-64, #1-72 0.0595 1.51 7/16-14 0.3701 9.40 M2 0.0630 1.60 M10x1 0.3780 9.60 #1-72 0.0669 1.70 M10x0.75 0.3819 9.70 #1 … tap & drill selection Chart 134 taps 136 dies 142 Re-threading die sets 146 threading tools 148 Combination sets 150. taps & dies 132 www.irwin.com taps & dies History of Quality and dependability For over 100 years, IRWIN HANSON has been providing the highest quality threading tools in the industry. For Metric sizes only. These thread series are obsolete. This works for both fine and coarse pitches, and also produces an approximate 75 percent thread. Pitch Dia d2=D2 max. 15.0. Tap size: NF/NC UNF/UNC: Threads per inch: Basic major dia (inches) Basic effective dia (inches) Basic minor dia of ext. The tap size chart provides a list of standard size taps, specifying the diameter and thread spacing, for fractional, metric, and screw sizes. In our case, the correct tap drill would be the closest to 3.4 mm from below, and that is the 3.3 mm or 0.13-inch tap drill. For example, the tap drill for 3/8-16 is 5/16. 75% Thread: Stainless Steel, Steels & Iron. The IRWIN HANSON name signifies dependability with professionals who … — (.0068 x % of Thread Desired) Threads Per Inch 068 x 250 — = .228 Dia. Standard Fit 75% Thread 50% Thread Screw Size Major Dia (mm) mm per Thread Drill Size Closest Imperial Drill Size Closest Imperial Drill Size Closest Imperial Drill Size Closest Imperial M1.5 x 0.35 1.5 0.35 1.15 #56 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. 9.25. 3.60. A rule of thumb is that the right tap drill is around 85% for coarse threads and 90% for fine threads which feature a higher number of threads per axial distance. Click here to return to the thread data chart page index. Tap Fractional Drill Bit Number Drill Bit Letter Drill Bit Threading Tapping Drill Size Chart Pitch Dia d2=D2 min. Thread Size: Tap Drill (mm) Thread Size: Tap Drill (mm) Thread Size: Tap Drill (mm) Thread Size: Tap Drill (mm) M4 x 0.35. eg for 3/4.10 UNC pitch = 0.1, diameter = … Fractional sizes are listed in inches, while metric sizes are listed in millimeters following the letter "M". NOTE: The tap drill size of a hole that will be cold form tapped is usually bigger than it cutting tap counterpart. For the fine threads, the size of a tap drill would be 90% of the major diameter. The tap size chart is a table that lists standard size taps, specifying the diameter and thread spacing, for fractional, metric, and screw sizes. * Non-standard drill sizes be necessary. eg for an M5x0.75 thread the tapping drill is 5-0.75mm = 4.25mm. PRACTICAL FORMULA - METRIC SIZES TO ESTABLISH TAP DRILL SIZES FOR METRIC SIZE … In the Unified Series the ½ inch size has 12 threads per inch, but the American Standard retains 13 threads per inch. The tap drill sizes shown for form taps are only a recommendation as a starting point. In many cases the hole diameter does not correspond to a numbered drill, so the closest millimeter drill should be selected. As a rule of thumb, for Metric threads, the tapping drill can be calculated by subtracting the pitch from the diameter of the thread. British Association Screw Threads or BA Screws Threads. And the bottom number in the stack is UNSF for “Super Fine”. M16 x 1. Diameter of thread minus the pitch equals the tap drill size. max. Machine Screw Size: Threads Per Inch: Minor Dia: Tap Drills: Clearance Hole Drills: Alum, Brass, & Plasitcs. If you’re working with the Metric Drill Bit size standards, then you may go through the Major Minus Pitch that decides the drill bit sizes for any taping. Minor Dia d3 max. All standard size taps come with at least one drill bit size that corresponds to it. The NPT - National Pipe Taper Threads - is based on the Briggs Standard Pipe Thread. In our tap drill chart for Standard sizes, the smaller pitch number on top is the coarser thread type with the other one (or two) being finer. The decimal equivalents of the diameters are shown in both English and Metric units. BA threads: tapping and clearance drills table BRITISH STANDARD BRASS (55º) 1/4 26 5.2 5/16 26 6.8 3/8 26 8.4 7/16 26 10.0 1/2 26 11.6 9/16 26 13.2 5/8 26 14.8 3/4 26 18.0 7/8 26 20.8 1 26 24.3 *Taper pipe threads of improved quality are obtained when the tapping hole is pre-formed using Sutton Taper Pipe Reamers. max. threads (inches) Basic minor dia of int. Tap Drill Charts | British Standard Pipe Threads BSW BSPP BSPT Pipe Tap Size Pitch (TPI) Drill Size (inch) Pitch (TPI) Drill Size (inch) Pitch (TPI) Drill Size* (inch) 1/16 60 0.046 (#56) 28 0.261 (G) - - 1/8 40 0.098 (#40) 28 11/32 28 21/64 1/4 20 0.196 (#9) 19 29/64 19 7/16 5/16 18 1/4 - - - - 3/8 16 5/16 19 19/32 19 37/64 7/16 14 23/64 - - - - 1/2 12 0.413 (Z) 14 3/4 14 23/32 9/16 12 … Major Dia d=D min. Depending on the material being tapped and the depth of the tapped hole, the hole size … max. US Tap and Drill Bit Size Table. Tap Drill Chart 129 Tap Drill Chart (Standard 2B) Nominal Pipe Tap Size NPT & NPTF w/o Reamer w/Reamer 1/16-27 CA 1/8-27 Q 21/64 1/4-18 7/16 27/64 3/8-18 9/16 9/16 1/2-14 45/64 11/16 3/4-14 29/32 57/64 1 - 11 1/ 2 1 9/ 64 1 1/ 8 11/ 4 - 11 1/ The following is a ANSI Standard Pipe Thread Recommended Tap size and Drilled Pilot Hole for Taper . Lower percentages such as “75% of the thread depth” are also widely used and considered safe. General information . Print this page . These are a bit bigger than the skinniest area of the male screw, but at the same time also smaller than the thickest area of that screw. (inch) (threads/inch) Size (inch) Size (inch) Size (inch) #0 0.06 80 0-80 3/64 0.0469 52 0.0635 50 0.07 #1 0.073 64 1-64 53 0.0595 48 0.076 46 0.081 #1 0.073 72 1-72 53 … O-Ring Sizes: Pipe Threads: Screw Extractors: Sheet Metal Gauges & Weights : Socket Head Cap Screws: Taper Calculations: Taper Pins: Taper Shank Dimensions: Washer Sizes: Wire Gauges: Wood Screw Dimensions: Imperial Tap Chart. Clearance Drill Sizes Tap Drill Clearance Drill 75% Thread for Aluminum, Brass, & Plastics 50% Thread for Steel, Stainless, & Iron Close Fit Standard Fit Screw Size (mm) Thread Pitch (mm) Drill Size (mm) Closest American Drill Drill Size (mm) Closest American Drill Drill Size (mm) Closest American Drill Drill Size (mm) Closest American Drill M1.5 0.35 1.15 56 1.25 55 1.60 1/16 1.65 … Specifically, the first number is called the UNC (Unified National Coarse) pitch. The NPT - National Pipe Taper Threads - is based on the Briggs Standard Pipe Thread.