Machinery's Handbook, 31st Edition
Taps
985
Table 5b. Standard Tap Dimensions Tolerances (Ground and Cut Thread) ANSI/ASME B94.9-2008 (R2018)
Tolerance, inch
Nominal Diameter Range, inch
Ground Thread 0.0300 0.0600 0.0500 0.0600 0.0900 0.1300 0.0300 0.0600 0.0015 0.0015 0.0020 0.0020 0.0030 0.0040 0.0060 0.0080
Cut Thread 0.0300 0.0600 0.0500 0.0600 0.0900 0.1300 0.0300 0.0600 0.0040 0.0050 0.0050 0.0070 0.0070 0.0040 0.0060
Over
To (inclusive)
Direction
Element
Length overall, L
0.5200 1.0100 0.0520 0.2230 0.5100 1.5100 0.0520 1.0100 0.0520 0.2230 0.6350 1.0100 1.5100 0.0520 0.5100
1.0100 2.0000 0.2230 0.5100 1.5100 2.0000 1.0100 2.0000 0.2230 0.6350 1.0100 1.5100 2.0000 0.5100 1.0100
± ± ± ± ± ± ± ± - - - - - - - -
Length of thread, I
Length of thread, I 2
Diameter of shank, d 1
Size of square, a
1.0100 0.0080 Entry Taper Length.— Entry taper length is measured on the full diameter of the thread-forming lobes and is the axial distance from the entry diameter position to the theoretical intersection of tap major diameter and entry taper angle. Beveled end threads provided on taps having internal center or incomplete threads retained when external center is removed. Whenever entry taper length is specified in terms of number of threads, this length is measured in number of pitches, P . Bottom length 1 2 2 1 pitches Plug length 3 5 pitches 2.0000 + + = = Entry diameter measured at the thread crest nearest the front of the tap is an appropriate amount smaller than the diameter of the hole drilled for tapping.
L
L
I
I 2
4
I
I
I
I
a
2
1
+0.000 -0.032
d
1
BLANK Design 2 with Optional Neck
BLANK Design 3
Optional Neck and Optional Shortened Thread Length, Ground and Cut Thread (Table 6)
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