Special Tap Dimensions Page

 


This page is for information only. Please advise if you find any errors on this page.


 

 

 

Special Taps Engineering Data
Ground Thread Length Tap Dimensions
Table 302


Ground Thread Dimensions

General Dimensions

Nominal Diameter
Range - Inches
    Tap Dimensions - Inches
Over To (Incl.) Machine
Screw
Size
Number

Nominal
Fractional
Diameter
(Inches)

Nominal
Metric
Diameter (Millimeters)
Style Length
Overall
A
Thread
Length
B
Square
Length
C
Shank
Dia.
D
Size of
Square
E
.052 .065 0 1/16 M1.6 1 1-5/8 5/16 3/16 .141 .110
.065 .078 1 ----- M1.8 1 1-11/16 3/8 3/16 .141 .110
.078 .091 2 ----- M2, M2.2 1 1-3/4 7/16 3/16 .141 .110
.091 .104 3 3/32 M2.5 1 1-13/16 1/2 3/16 .141 .110
.104 .117 4 ----- ----- 1 1-7/8 9/16 3/16 .141 .110
.117 .130 5 1/8 M3, M3.15 1 1-15/16 5/8 3/16 .141 .110
.130 .145 6 ----- M3.5 1 2 11/16 3/16 .141 .110
.145 .171 8 5/32 M4 1 2-1/8 3/4 1/4 .168 .131
.171 .197 10 3/16 M4.5, M5 1 2-3/8 7/8 1/4 .194 .152
.197 .223 12 7/32 ----- 1 2-3/8 15/16 9/32 .220 .165
.223 .260 14 1/4 M6, M6.3 2 2-1/2 1 5/16 .255 .191
.260 .323   5/16 M7, M8 2 2-23/32 1-1/8 3/8 .318 .238
.323 .395   3/8 M10 2 2-15/16 1-1/4 7/16 .381 .286
.395 .448   7/16 ----- 3 3-5/32 1-7/16 13/32 .323 .242
.448 .510   1/2 M12, M12.5 3 3-3/8 1-21/32 7/16 .367 .275
.510 .573   9/16 M14 3 3-19/32 1-21/32 1/2 .429 .322
.573 .635   5/8 M16 3 3-13/16 1-13/16 9/16 .480 .360
.635 .709   11/16 M18 3 4-1/32 1-13/16 5/8 .542 .406
.709 .760   3/4 ----- 3 4-1/4 2 11/16 .590 .442
.760 .823   13/16 M20 3 4-15/16 2 11/16 .652 .489
.823 .885   7/8 M22 3 4-11/16 2-7/32 3/4 .697 .523
.885 .948   15/16 M24 3 4-29/32 2-7/32 3/4 .760 .570
.948 1.010   1 M25 3 5-1/8 2-1/2 13/16 .800 .600
1.010 1.073   1-1/16 M27 3 5-1/8 2-1/2 7/8 .896 .672
1.073 1.135   1-1/8 ----- 3 5-7/16 2-9/16 7/8 .896 .672
1.135 1.198   1-3/16 M30 3 5-7/16 2-9/16 1 1.021 .766
1.198 1.260   1-1/4 ----- 3 5-3/4 2-9/16 1 1.021 .766
1.260 1.323   1-5/16 M33 3 5-3/4 2-9/16 1-1/16 1.108 .831
1.323 1.385   1-3/8 ----- 3 6-1/16 3 1-1/16 1.108 .831
1.385 1.448   1-7/16 M36 3 6-1/16 3 1-1/8 1.233 .925
1.448 1.510   1-1/2 ----- 3 6-3/8 3 1-1/8 1.233 .925
1.510 1.635   1-5/8 M39 3 6-11/16 3-3/16 1-1/8 1.305 .979
1.635 1.760   1-3/4 M42 3 70/1 3-3/16 1-1/4 1.430 1.072
1.760 1.885   1-7/8 ----- 3 7-5/16 3-9/16 1-1/4 1.519 1.139
1.885 2.010   2 M48 3 7-5/8 3-9/16 1-3/8 1.644 1.233
2.010 2.135   2-1/8 ----- 3 8 3-9/16 1-3/8 1.769 1.327
2.135 2.260   2-1/4 M56 3 8-1/4 3-9/16 1-7/16 1.894 1.420
2.260 2.385   2-3/8 ----- 3 8-1/2 4 1-7/16 2.019 1.514
2.385 2.510   2-1/2 ----- 3 8-3/4 4 1-1/2 2.100 1.575
2.510 2.635   2-5/8 M64 3 8-3/4 4 1-1/2 2.225 1.669
2.635 2.760   2-3/4 ----- 3 9-1/4 4 1-9/16 2.350 1.762
2.760 2.885   2-7/8 M72 3 9-1/4 4 1-9/16 2.475 1.856
2.885 3.010   3 ----- 3 9-3/4 4-9/16 1-5/8 2.543 1.907
3.010 3.135   3-1/8 ----- 3 9-3/4 4-9/16 1-5/8 2.668 2.001
3.135 3.260   3-1/4 M80 3 100/1 4-9/16 1-3/4 2.793 2.095
3.260 3.385   3-3/8   3 10 4-9/16 1-3/4 2.883 2.162
3.385 3.510   3-1/2   3 10-1/4 4-15/16 2 3.008 2.256
3.510 3.635   3-5/8 M90 3 10-1/4 4-15/16 2 3.133 2.350
3.635 3.760   3-3/4   3 10-1/2 5-5/16 2-1/8 3.217 2.413
3.760 3.885   3-7/8   3 10-1/2 5-5/16 2-1/8 3.342 2.506
3.885 4.010   4 M100 3 10-3/4 5-5/16 2-1/4 3.467 2.600


Special Taps

Unless otherwise specified:

Special taps over 1.010" to 1.510" diameter inclusive, having 14 or more threads per inch or 1.75 millimeter pitch and finer, and sizes over 1.510" diameter with 10 or more threads per inch or 2.5 millimeter pitch and finer, are made to general dimensions shown in Table 303.

Special ground thread taps are made to limits shown in Table 331 for Unified Inch Screw Threads and Table 341 for Metric M-Profile Screw Threads.

 

Notes:

Ground thread taps, sizes .395" and smaller, have external center on thread end (may be removed on bottoming taps). Sizes .223" and smaller, have external center on shank end; sizes .224" thru .395" have truncated partial cone centers on shank end (length of cone approximately 1/4 of diameter of shank). Sizes over .395" have internal center in thread and shank ends.

For standard thread limits and tolerances for Unified Inch Screw Threads see Table 327 and for Metric Threads see Table 337.

For eccentricity tolerances of tap elements see Table 317.

Tables 317, 327, 331, 337, and 341 can be found in the "Metal Cutting Tool Handbook" published by the U.S.C.T.I.




Back to Top of Page

 

Special Taps Engineering Data
Short Thread Length Tap Dimensions
Table 302-A


Short Thread Dimensions

General Dimensions

Nominal Diameter
Range - Inches
    Tap Dimensions - Inches
Over To (Incl.) Machine
Screw
Size
Number

Nominal
Fractional
Diameter
(Inches)

Nominal
Metric
Diameter
(mm)
Style Length
Overall
A
*Length
B
Square
Length
C
Shank
Dia.
D
Size of
Square
E
Thread
**Length
F
.104 .117 4 ----- ----- 1 1-7/8 9/16 3/16 .141 .110 5/16
.117 .130 5 1/8 M3, M3.15 1 1-15/16 5/8 3/16 .141 .110 5/16
.130 .145 6 ----- M 3.5 1 2 11/16 3/16 .141 .110 3/8
.145 .171 8 5/32 M4 1 2-1/8 3/4 1/4 .168 .131 3/8
.171 .197 10 3/16 M4.5, M5 1 2-3/8 7/8 1/4 .194 .152 1/2
.197 .223 12 7/32 ----- 1 2-3/8 15/16 9/32 .220 .165 1/2
.223 .260 14 1/4 M6, M6.3 2 2-1/2 1 5/16 .255 .191 5/8
.260 .323   5/16 M7, M8 2 2-23/32 1-1/8 3/8 .318 .238 11/16
.323 .395   3/8 M10 2 2-15/16 1-1/4 7/16 .381 .286 3/4
.395 .448   7/16 ----- 3 3-5/32 - 13/32 .323 .242 7/8
.448 .510   1/2 M12, M12.5 3 3-3/8 - 7/16 .367 .275 15/16
.510 .573   9/16 M14 3 3-19/32 - 1/2 .429 .322 1
.573 .635   5/8 M16 3 3-13/16 - 9/16 .480 .360 1-3/32
.635 .709   11/16 M18 3 4-1/32 - 5/8 .542 .406 1-3/32
.709 .760   3/4 ----- 3 4-1/4 - 11/16 .590 .442 1-7/32
.760 .823   13/16 M20 3 4-15/32 - 11/16 .652 .489 1-7/32
.823 .885   7/8 M22 3 4-11/16 - 3/4 .697 .523 1-11/32
.885 .948   15/16 M24 3 4-29/32 - 3/4 .760 .570 1-11/32
.948 1.010   1 M25 3 5-1/8 - 13/16 .800 .600 1-1/2

* "B" based on Table 302, column B and shall be no less than minimum Table 302 thread length.
**"F" based on the length of 12 pitches of the UNC series.

Notes: 1.) "F" is minimum value and has no tolerance.
2.) Unless otherwise specified, all tolerances are in accordance with Table 302.


Special Taps Engineering Data
Ground Thread Fine Pitch Tap Dimensions
Short Series, Ground Thread Dimensions
Table 303


Fine Pitch Thread

Unless otherwise specified, special taps 1.010" to 1.510" diameter inclusive, have 14 or more threads per inch or 1.75 millimeter pitch and finer, and sizes over 1.510" diameter with 10 or more threads per inch, or 2.5 millimeter pitch and finer, will be made to the general dimensions shown below.

General Dimensions

Nominal Diameter
Range - Inches
  Tap Dimensions - Inches
Over To (Incl.)

Nominal
Fractional
Diameter
(Inches)

Nominal
Metric
Diameter
(Millimeters)
Overall
Length
A
Thread
Length
B
Square
Length
C
Shank
Dia.
D
Size of
Square
E
1.010
1.073
1.135
1.073
1.135
1.198
1-1/16
1-1/8
1-3/16
M27

M30
4
4
4
1-1/2
1-1/2
1-1/2
7/8
7/8
1
.896
.896
1.021
.672
.672
.766
1.198
1.260
1.323
1.260
1.323
1.385
1-1/4
1-5/16
1-3/8
M33 4
4
4

1-1/2
1-1/2
1-1/2

1
1
1
1.021
1.108
1.108
.766
.831
.831

1.385
1.448
1.510

1.448
1.510
1.635
1-7/16
1-1/2
1-5/8
M36

M39
4
4
5
1-1/2
1-1/2
2
1
1
1-1/8
1.233
1.233
1.305
.925
.925
.979
1.635
1.760
1.885
1.760
1.885
2.010
1-3/4
1-7/8
2"
M42

M48
5
5
5
2
2
2
1-1/4
1-1/4
1-3/8
1.430
1.519
1.644
1.072
1.139
1.233
2.010
2.135
2.260
2.135
2.260
2.385
2-1/8
2-1/4
2-3/8
M56

5-1/4
5-1/4
5-1/4

2
2
2
1-3/8
1-7/16
1-7/16
1.769
1.894
2.019
1.327
1.420
1.514
2.385
2.510
2.635
2.510
2.635
2.760
2-1/2
2-5/8
2-3/4
M64 5-1/4
5-1/2
5-1/2
2
2
2
1-1/2
1-1/2
1-1/2
2.100
2.100
2.100
1.575
1.575
1.575
2.760
2.885
3.010
2.885
3.010
3.135
2-7/8
3"
3-1/8
M72 5-1/2
5-1/2
5-3/4
2
2
2
1-1/2
1-1/2
1-1/2
2.100
2.100
2.100
1.575
1.575
1.575
3.135
3.260
3.385
3.260
3.385
3.510
3-1/4
3-3/8
3-1/2
M80 5-3/4
5-3/4
5-3/4
2
2
2
1-1/2
1-1/2
1-1/2
2.100
2.100
2.100
1.575
1.575
1.575
3.510
3.635
3.760
3.885
3.635
3.760
3.885
4.010
3-5/8
3-3/4
3-7/8
4"
M90


M100
6
6
6
6
2
2
2
2
1-3/4
1-3/4
1-3/4
1-3/4
2.100
2.100
2.100
2.100
1.575
1.575
1.575
1.575

For tolerances see Table 302.




 

 

Special Taps Engineering Data
Ground Thread Extension Tap Dimensions
Table 303-A



Extension Tap Dimensions

General Dimensions

 

The "T" length of the shank diameter of extension taps is ground to close tolerances whereas the remaining portion of the shank has ordinary bar tolerances. In special applications where the shank is used as a bushing, the entire shank length may be ground upon request.

Size B
Thread Length

D
Shank
Length

C
Square
Length
Square
Size
T**
Ground Shank
Length
6
8
10
11/16
3/4
7/8
.141
.168
.194
3/16
1/4
1/4
.110
.131
.152
1-1/8
1-1/4
1-3/8

1/4
1/4*
5/16

1"
1"
1-1/8
.255
.185
.318
5/16
1/4
3/8
.191
.138
.238
1-1/2
Full Length
1-9/16
5/16*
3/8
3/8*
1-1/8
1-1/4
1-1/4
.240
.381
.275
9/32
7/16
3/8
.180
.286
.206
Full Length
1-5/8
Full Length
7/16
1/2
9/16
1-7/16
1-21/32
1-21/32
.323
.367
.429
13/32
7/16
1/2
.242
.275
.322
1-11/16
1-11/16
1-7/8
5/8
3/4
7/8
1-13/16
2"
2-7/32
.480
.590
.697
9/16
11/16
3/4
.360
.442
.523
2"
2-1/4
2-1/2
1"
1-1/8
1-1/4
1-3/8
1-1/2
2-1/2
2-9/16
2-9/16
3"
3"
.800
.896
1.021
1.108
1.233
13/16
7/8
1"
1-1/16
1-1/8
.600
.672
.766
.831
.925
2-5/8
2-3/4
2-7/8
3"
3"

*
**

Small Shank
North American Tool's manufacturing standards on the "T" dimensions are longer than shown in Table 303-A and Table 310.

 


 

Special Taps Engineering Data
Ground Thread Pulley Tap Dimensions
Table 310


Ground Thread Pulley Tap Dimensions


General Dimensions

 
Dimensions-Inches
Diameter
of
Tap
(inches)
Length
Overall
A

Length
of
Thread
B

Length
of
Square
C
Diameter
of
Shank
D
Length
of Close
Tolerance
T*
Size
of
Square
E
Length
of
Neck
K**
1/4
5/16
3/8
7/16
3,8
6,8
6,8,10
6,8
1
1-1/8
1-1/4
1-7/16
5/16
3/8
7/16
1/2
.255
.318
.381
.444

1-1/2
1-9/16
1-5/8
1-11/16

.191
.238
.286
.333

3/8
3/8
3/8
7/16

1/2
5/8
3/4
6,8,10,12
6,8,10,12
10,12

1-21/32
1-13/16
2

9/16
11/16
3/4
.507
.633
.759
1-11/16
2
2-1/4
.380
.475
.569
1/2
5/8
3/4

 

 


Formula (approximate)
Diameter of Shank "D" = Maximum Major Diameter
Size of Square = Dia. of Shank "D" X .75 to nearest .001"

 

NOTES:

*

T is minimum length of shank which is held to eccentricity tolerances.
North American Tool's manufacturing standards on the "T" dimensions are longer than shown.

 

 

Back to Top of Page

 

 

Special Taps Engineering Data
Ground Thread Pipe Tap Dimensions
Table 311



Ground Thread Pipe Tap Dimensions

General Dimensions

 
Dimensions-Inches
Nominal
Size
(inches)
Length
Overall
A

Length
of
Thread
B

Length
of
Square
C
Diameter
of
Shank
D
Size
of
Square
E
1/16
1/8
1/8
2-1/8
2-1/8
2-1/8
11/16
3/4
3/4

3/8
3/8
3/8

.3125
.3125
.4375
.234
.234
.328

1/4
3/8
1/2

2-7/16
2-9/16
3-1/8
1-1/16
1-1/16
1-3/8
7/16
1/2
5/8
.5625
.7000
.6875
.421
.531
.515
3/4
1"
1-1/4
3-1/4
3-3/4
4"
1-3/8
1-3/4
1-3/4
11/16
13/16
15/16
.9063
1.1250
1.3125
.679
.843
.984
1-1/2
2"
2-1/2
4-1/4
4-1/2
5-1/2
1-3/4
1-3/4
2-9/16
1"
1-1/8
1-1/4
1.5000
1.8750
2.2500
1.125
1.406
1.687
3"
3-1/2
4"
6"
6-1/2
6-3/4
2-5/8
2-11/16
2-3/4
1-3/8
1-1/2
1-5/8
2.6250
2.8125
3.0000
1.968
2.108
2.250

 

Tolerances

Element Range

Direction

Tolerance
Length Overall -A


Length of Thread - B



Length of Square - C


Diameter of Shank - D




Size of Square - E
1/16" to 3/4" incl.
1" to 4" incl.

1/16" to 3/4" incl.
1" to 1-1/4" incl.
1-1/2" to 4" incl.

1/16" to 3/4" incl.
1" to 4" incl.

1/16" to 1/8" incl.
1/4" to 1/2" incl.
3/4" to 1" incl.
1-1/4" to 4" incl.

1/16" to 1/8" incl.
1/8" to 3/4" incl.
1" to 4" incl.
Plus or Minus
Plus or Minus

Plus or Minus
Plus or Minus
Plus or Minus

Plus or Minus
Plus or Minus

Minus
Minus
Minus
Minus

Minus
Minus
Minus
1/32"
1/16"

1/16"
3/32"
1/8"

1/32"
1/16"

.0015"
.0020"
.0020"
.0030

.0040"
.0060"
.0080"


 

Back to Top of Page

 

Special Taps Engineering Data
Tandem ACME Tap Dimensions
Table 311



Tandem ACME Tap Dimensions

General Dimensions

 
      Round Shank Square Maximum
Depth of Nut
Size &
Pitch
A
Overall
Length

B
Length
Thread
End

C
Length
D
Dia.
E
Length
F
Across
Flats
Bronze
& Steel
Brass &
Cast Iron
1/4 - 16
5/16 - 14
3/8 - 12
1/2 - 10
5/8 - 8
3"
3-13/32
4-1/16
5"
6-1/4

1-3/4
1-7/8
2-1/8
2-9/16
3-3/16

1"
1-1/4
1-5/8
2"
2-1/2
.185
.220
.255
.367
.480
1/4
3/32
5/16
7/16
9/16

.138
.165
.191
.275
.360

1/2
5/8
5/8
1"
1-1/4

3/4
7/8
1"
1-1/2
1-7/8

3/4 - 6
7/8 - 6
1" - 5
1-1/8 - 5
1-1/4 - 5
7-15/16
8-5/8
10-1/8
10-3/4
11-1/8
4-5/16
4-3/8
5-1/4
5-1/4
5-1/4
3"
3-1/2
4"
4-1/2
4-3/4
.542
.697
.697
.800
.896
5/8
3/4
3/4
13/16
7/8

.406
.523
.523
.600
.672

1-1/2
1-3/4
2"
2-1/4
2-1/2
2-1/4
2-5/8
3"
3-3/8
3-3/4
1-3/8 - 4
1-1/2 - 4
1-3/4 - 4
2" - 4
12-1/4
12-5/8
13-3/8
14-7/8
5-7/8
5-7/8
5-7/8
6-1/2

5-1/8
5-1/2
6-1/4
7

1.108
1.233
1.430
1.644
1-1/4
1-1/4
1-1/4
1-3/8
.831
.925
1.072
1.233
2-3/4
3"
3-1/2
4"
4-1/8
4-1/2
5"
6"


 

 

 

Back to Top of Page

 

link to tap and die index page

link to "how to order special taps"