15/16 - 16 16-UN - Basic Thread Dimensions

Property Inch mm
Nominal Diameter 0.937 23.8
Pitch (TPI)16
Pitch (Distance) 0.0625 1.588
Pitch Diameter 0.8964 22.769
Minor Diameter 0.8626 21.91
Thread Height 0.0338 0.859
Addendum 0.0203 0.516
Crest (External)
Root (Internal)
0.0078 0.198
Tap Drill Size
(75% depth)
0.876 22.25
Lead Angle
(Single Start)
1.27°
Thread Family Unified Constant Pitch 16 TPI (16-UN)
Relevant Standards ASME B1.1-2003
Equivalent Metric ThreadM24 X 1.5

For more threading data scroll down, or use the Thread Calculator

Table of Content


15/16 - 16 16-UN Possible Thread Classes

External Threads

Choose tolerance class: 2A, 3A

Metric ISO External Thread - Tolerance sketch

Internal Threads

Choose tolerance class: 2B, 3B

Metric ISO Internal Thread - Tolerance sketch

15/16 - 16 16-UN 2A (External)

* Permisable values for thread Class 2A

# Description Value (Inch) Value (mm)
es Allowance 0.0014 (Ref) 0.036 (Ref)
d Major Diameter 0.9262 - 0.9356 23.525 - 23.764
d2 Pitch Diameter 0.8903 - 0.895 22.614 - 22.733
d3 Minor Diameter
(UNR Only)
0.8612 (Ref) 21.874 (Ref)
α Varation of 30° anngle (+/-)
P Varation of pitch (+/-) 0.0013 (Ref) 0.033 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


15/16 - 16 16-UN 3A (External)

* Permisable values for thread Class 3A

# Description Value (Inch) Value (mm)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 0.9276 - 0.937 23.561 - 23.8
d2 Pitch Diameter 0.8929 - 0.8964 22.68 - 22.769
d3 Minor Diameter
(UNR Only)
0.8626 (Ref) 21.91 (Ref)
α Varation of 30° anngle (+/-)
P Varation of pitch (+/-) 0.001 (Ref) 0.025 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


15/16 - 16 16-UN 2B (Internal)

* Permisable values for thread Class 2B

# Description Value (Inch) Value (mm)
D1 Minor Diameter 0.869 - 0.883 22.073 - 22.428
D2 Pitch Diameter 0.8964 - 0.9025 22.769 - 22.924
D Major Diameter 0.9370 (Min) 23.8 (Min)
α Varation of 30° anngle (+/-)
P Varation of Pitch (+/-) 0.0018 (Ref) 0.046 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


15/16 - 16 16-UN 3B (Internal)

* Permisable values for thread Class 3B

# Description Value (Inch) Value (mm)
D1 Minor Diameter 0.8693 - 0.8778 22.08 - 22.296
D2 Pitch Diameter 0.8964 - 0.901 22.769 - 22.885
D Major Diameter 0.9370 (Min) 23.8 (Min)
α Varation of 30° anngle (+/-)
P Varation of Pitch (+/-) 0.0013 (Ref) 0.033 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


Tap Drill Sizes for 15/16 - 16 16-UN

  • If not specified, assume a thread depth of 75%.
  • You can learn more about thread depth in tapping here.
  • To get the tap drill size in other depths, use our Tap Drill Size Calculator .
Thread Depth Tap Drill Size (Inch) Tap Drill Size (mm)
55% 0.892 22.66
60% 0.888 22.56
65% 0.884 22.46
70% 0.880 22.36
75% 0.876 22.25
80% 0.872 22.15
85% 0.868 22.05

Over Wire Measurements for 15/16 - 16 16-UN


* OverWire is a measuring method to obatin the pitch diameter of threads. It is mostly used when a manufacturer does not have a Go/Nogo gauge for a thread. You can learn more about it here

Inch mm
Permissible Wire Diameter Range 0.0316 - 0.0631 0.802 - 1.604
Ideal Wire Diameter 0.0361 0.917
Possible Wires
From Standard Sets
* 0.866
* 1.01
* 1.155
* 1.443

Once you knoe your wire diameter, you need to find out what is the premissable Measurement for your pitch diameter (Depending on the class). Use our Over Wire Calculator to find out!


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