7/16-20 UNF Thread Specs
Standard: ASME B1.1 (UNF)
Find the technical dimensions, threads per inch (TPI), and tapping guidelines for the 7/16-20 UNF unified thread.
Compliant with the ASME B1.1 standard, this size has a nominal major diameter of 0.4375 inches (11.11 mm) with a pitch of 0.05 inches (TPI of 20).
For general engineering or fastening, the standard recommended tap drill is 0.3875 inches (9.84 mm) to achieve adequate thread engagement.
Dimensional Specifications (Inches & mm)
Size Designation
7/16-20 UNF
Major Diameter (Nominal)
0.4375 in(11.11 mm)
TPI (Threads per Inch)
20
Pitch
0.05 in
Pitch Diameter
0.405 in(10.29 mm)
Minor Diameter (Ext)
0.3834 in(9.74 mm)
Minor Diameter (Int)
0.3888 in(9.88 mm)
Thread Height
0.0433 in
Drilling & Strength Specs
Tap Drill Size
0.3875 in(9.84 mm)
Stress Area
0.1187 in²(76.59 mm²)
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Frequently Asked Questions
What is the tap drill size for 7/16-20 UNF?
The recommended tap drill size for a 7/16-20 UNF thread is 0.3875 inches (approx. 9.84 mm) to achieve standard thread engagement.
How many threads per inch (TPI) does a 7/16-20 UNF bolt have?
A standard 7/16-20 UNF thread has exactly 20 threads per inch (TPI), with a corresponding linear pitch of 0.05 inches.
What is the major diameter of a 7/16-20 UNF thread in millimeters?
The nominal major diameter of a 7/16-20 UNF thread is 0.4375 inches, which converts to 11.11 mm.