7/16 - 28 UNEF - Basic Thread Dimensions

Property Inch mm
Nominal Diameter 0.437 11.1
Pitch (TPI)28
Pitch (Distance) 0.0357 0.907
Pitch Diameter 0.4138 10.511
Minor Diameter 0.3945 10.02
Thread Height 0.0193 0.49
Addendum 0.0116 0.295
Crest (External)
Root (Internal)
0.0045 0.114
Tap Drill Size
(75% depth)
0.402 10.22
Lead Angle
(Single Start)
1.57°
Thread Family Unified Extra-Fine pitch (UNEF)
Relevant Standards ASME B1.1-2003
Equivalent Metric ThreadM11 X 1

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

Table of Content


7/16 - 28 UNEF 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

7/16 - 28 UNEF 2A (External)

* Permisable values for thread Class 2A

# Description Value (Inch) Value (mm)
es Allowance 0.001 (Ref) 0.025 (Ref)
d Major Diameter 0.4295 - 0.436 10.909 - 11.074
d2 Pitch Diameter 0.4094 - 0.4128 10.399 - 10.485
d3 Minor Diameter
(UNR Only)
0.3935 (Ref) 9.995 (Ref)
α Varation of 30° anngle (+/-) 1.3333°
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


7/16 - 28 UNEF 3A (External)

* Permisable values for thread Class 3A

# Description Value (Inch) Value (mm)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 0.4305 - 0.437 10.935 - 11.1
d2 Pitch Diameter 0.4113 - 0.4138 10.447 - 10.511
d3 Minor Diameter
(UNR Only)
0.3945 (Ref) 10.02 (Ref)
α Varation of 30° anngle (+/-) 1.3333°
P Varation of pitch (+/-) 0.0007 (Ref) 0.018 (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


7/16 - 28 UNEF 2B (Internal)

* Permisable values for thread Class 2B

# Description Value (Inch) Value (mm)
D1 Minor Diameter 0.398 - 0.407 10.109 - 10.338
D2 Pitch Diameter 0.4138 - 0.4182 10.511 - 10.622
D Major Diameter 0.4370 (Min) 11.1 (Min)
α Varation of 30° anngle (+/-) 1.3333°
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


7/16 - 28 UNEF 3B (Internal)

* Permisable values for thread Class 3B

# Description Value (Inch) Value (mm)
D1 Minor Diameter 0.3983 - 0.4046 10.117 - 10.277
D2 Pitch Diameter 0.4138 - 0.4171 10.511 - 10.594
D Major Diameter 0.4370 (Min) 11.1 (Min)
α Varation of 30° anngle (+/-) 1.3333°
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


Tap Drill Sizes for 7/16 - 28 UNEF

  • 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% 0.411 10.45
60% 0.409 10.39
65% 0.407 10.33
70% 0.405 10.27
75% 0.402 10.22
80% 0.400 10.16
85% 0.398 10.10

Over Wire Measurements for 7/16 - 28 UNEF


* 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 0.018 - 0.0361 0.458 - 0.916
Ideal Wire Diameter 0.0206 0.524
Possible Wires
From Standard Sets
* 0.018
* 0.0193
* 0.0206
* 0.0214
* 0.0222
* 0.0241
* 0.0262
* 0.0289
* 0.462
* 0.52
* 0.577
* 0.722
* 0.866

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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