STANDARD TAPS SPEED RECOMMENDATIONS - Industrial …

1 & Dies197 STANDARD TAPSSPEED RECOMMENDATIONSSPEEDS shown are suggested starting points only and may be increased or decreased depending on actual material and machining conditions. Start conservatively and increase until the machining cycle is SPEEDS may be increased for coated taps, spiral point taps, fine pitch taps and when the percentage of thread is SPEEDS may need to be decreased for uncoated taps, spiral flute taps, coarse pitch taps, bottoming taps, difficult materials, longer thread lengths, and when the percentage of thread is FORMING TAPS generally form threads more efficiently at higher speeds.

2 Suggested speeds are 50% to 100% higher than the suggested speeds for cutting taps in similar TAP SPEEDS should be between one-half and three-quarters of the speeds of taps of comparable diameter and MaterialBrinell Hardness(BHN)Surface SPEED (SFM)Low Carbon Steel 1018, 12L12, 1108, 1213 12065 Low & Medium Carbon Steel 1018, 1551, 11L44120 - 25040 Medium Carbon and Alloyed Steel 1040, 1140, 4340, 8640 25040 Tool and Die Steels P20, A2, D2, H12 25020 Tool and Die Steels P20, A2, D2, H12250 - 35015 Free Machining Stainless Steels 303, 410, 416, 440F 26035 Moderate Machining Stainless Steels 304, 316 30025 Difficult Machining Stainless Steels 17-4PH, 316L.

3 AM350 30010 Cast Iron Soft Gray 16070 Cast Iron Gray160 - 26060 Cast Iron Ductile25050 Cast Iron Malleable250 - 33035 Titanium Alloys Commercially Pure - 17020 Titanium Alloys Ti-6AI-4V, ASTM B367 Grades C-3, C-4 25015 High Temperature Alloys Inconel, Hastelloy, Waspaloy 15025 High Temperature Alloys Inconel, Hastelloy, Waspaloy150 - 25010 Aluminum Alloys 2025, 6061, A140, 150100 Copper Alloys Brass and Bronze 20050 Magnesium Alloys AZ80A, HM12A, AM60A, ZE41A50 - 9070 Tool Coatings Also & drill SizesPIPE TAP drill SIZESTAP SIZENPT**TAP drill SIZENPTF**TAP drill SIZENPSTAP drill SIZENPSFTAP drill SIZE1/16DC1/4D1/8 RQSR1/47/167/1629/647/163/837/649/1619/3 237/641/223/3245/6447/6445/643/459/6429/ 3215/1659/6411-5/321-9/641-3/161-5/321-1 /41-1/21-31/641-33/64** For tapping without reaming1-1/21-47/641-23/321-3/422-7/322- 3/162-7/322-1/22-5/82-39/642-21/3233-1/4 3-15/64 TAP drill SIZESMETRIC TAP drill SIZESC utting Taps based on approx.

4 75% threadForming Taps based on approx. 65% threadCutting Taps based on approx. 75% threadForming Taps based on approx. 65% threadTAP SIZECUTTING TAP drill SIZEFORMING TAP drill SIZETAP SIZECUTTING TAP drill SIZEFORMING TAP drill SIZE0-803/64No. x x x 492-56No. 505 x 422-64No. x 413-48No. 47No. 43M3 x 343-56No. x 43No. 39M4 x x 39No. 33M5 x 19No. 135-44No. x 15mmNo. 26-32No. 361/8M7 x x 29No. 25M8 x 1J19/648-36No. 29No. 24M10 x 2511/64M10 x 21No. 16M12 x 175mmM12 x 15No. 8M14 x 212mm33/641/4-20No.

5 7No. 1M14 x 3AM16 x 214mm19/325 x x x x x x x x 353/6457/649/16-1231/6417/32M24 x 222mm* Reaming Recommended9/16-1833 x 324mm5/8-1117 x 263/645/8-1837 x *3/4-1021/3245/64M30 x 21-7/64*3/4-1611/1623/32M33 x *7/8-949/64M33 x 231mm*7/8-1413/16M36 x 432mm*1-87/8M36 x 333mm*1-1259/64M39 x 435mm*1-1415/16M39 x 336mm*Cutting Taps & Thread Forming & Dies199 Tap drill Sizes STI (Screw Thread Insert) TapsALUMINUMSTEEL, PLASTIC, MAGNESIUMDECIMALMINOR (AFTER TAPPING)DECIMALMINOR (AFTER TAPPING)STITAPEQUIV. OFTAPEQUIV.

6 OFTAPDRILLTAP DRILLDRILLTAP DRILLSIZESIZE(INCHES) (INCHES) - 40# # - 40# # - 32# # - 40# # - 32# # 24 . # - 32# . - 24# # - 20 .. - . - - 24 . - - 24 .. - 14 .. - 20 .. - 13 .. - 20 .. : Tap Drills listed above should produce holes within the required limits. However, variations in material and equipment may require the use of drills which are larger or smaller than those : Minor Diameter Limits for steel, plastic, and magnesium are such as to allow for material contraction and provide maximum tap for Obtaining Tap drill Sizes for Cutting Taps: Major Dia.

7 01299 X Amt. of percentage of full thread = Drilled Hole* of Thread No. of threads per inch size Note: Select nearest commercial stock of Full Thread for Other drill Sizes No. of Threads Major Dia. Selected Percentage of per Inch x of Thread drill Dia. = Full Thread .01299 Formula For Obtaining Tap drill Sizes For Thread Forming Taps: * drill Hole = Basic Major Dia..0068 x Percentage of Full Thread size (inches) of thread (inches) No. of Threads per Inch *Drilled Hole = Basic Major Dia. Percentage of Full Thread X mm Pitch size (mm) of thread (mm) *Note: drill size should be smaller than hole size by the probable amount the drill will cut & TapsClass of Fit RecommendationsThese tap RECOMMENDATIONS will produce the specified class of fit in most applications.

8 Threads produced should be checked with thread plug gages to ensure that the threads meet required specifications. Threads that gage loose or tight may require experimentation with taps of lower or higher pitch diameter limit ( H or D number).Unified and American National Screw ThreadsNominal SizeThreads Per InchRecommended Tap for Class of ThreadPitch Diameter Limits for Class of Thread UNCUNFC lass 2 BClass 3 BMinimum (Basic)Maximum Class 2 BMaximum Class 3B0 80H2 H1 . H2 H1 . 72H2 H1.

9 H2 H1 . 64H2 H1 . H2 H1 . 56H2 H1 . H2 H2 . 48H2 H1 . H2 H2 . 44H2 H1 . H3 H2 . 40H2 H2 . H3 H2 . 36H2 H2 . H3 H3 . 32H3 H2 . H3 H3 . 28H3 H3 . H5 H3 . 28H4 H3 . H5 H3 . 24H4 H3 . H5 H3 . 24H4 H3 . H5 H3 . 20H5 H3 . H5 H3 . 20H5 H3 . H5 H3 . 18H5 H3 . H5 H3 . 18H5 H3 . H5 16H5 H3 . H6 H4 . 14H6 H4 . H6 H4 . 12H6 H4 . 14* H6 H4 . 1/87 H8 H4 1/8 12H6 H4 1/47 H8 H4 1/4 12H6 H4 3/86 H8 H4 3/8 12H6 H4 1/26 H8 H4 1/2 12H6 H4 * & Dies201 STANDARD Metric TapsClass of Fit RecommendationsThese tap RECOMMENDATIONS will produce the specified class of fit in most applications.

10 Threads produced should be checked with thread plug gages to ensure that the threads meet required specifications. Threads that gage loose or tight may require experimentation with taps of lower or higher pitch diameter limit ( H or D number).Metric ThreadsSize mmPitch mmRecommended Tap for Class of ThreadPitch Diameter Limits for Class of ThreadClass 4H Class 6H Minimum (Basic) Maximum Class 4H Maximum Class D3 D3 D3 D3 D3 D2 D3 D4 D3 D4 D4 D3 D4 D3 1D3 D5 D4 1D3 D5 D5 1D3 D5 D5 1D3 D5 D6 D5 1D3 D5 D5 D6 D5 D5 2D3 D7 D6 D5 2D4 D7 D6 D7 D6 D7 D6 D7 D6 3D4 D8 2D4 D7 D5 D5 3D5 D8 2D5 D7 D9 2D5 D7 2D5 D7 D9 2D5 D7 4D5 D9 3D5 D8 2D5 D7 4D6 D9 3D6 D8 & Thread Forming TapsClass of Fit RecommendationsThese tap RECOMMENDATIONS