15/16-20 UNEF Thread Specs
Standard: ASME B1.1 (UNEF)
Find the technical dimensions, threads per inch (TPI), and tapping guidelines for the 15/16-20 UNEF unified thread.
Compliant with the ASME B1.1 standard, this size has a nominal major diameter of 0.9375 inches (23.81 mm) with a pitch of 0.05 inches (TPI of 20).
For general engineering or fastening, the standard recommended tap drill is 0.8875 inches (22.54 mm) to achieve adequate thread engagement.
Dimensional Specifications (Inches & mm)
Size Designation
15/16-20 UNEF
Major Diameter (Nominal)
0.9375 in(23.81 mm)
TPI (Threads per Inch)
20
Pitch
0.05 in
Pitch Diameter
0.905 in(22.99 mm)
Minor Diameter (Ext)
0.8834 in(22.44 mm)
Minor Diameter (Int)
0.8888 in(22.58 mm)
Thread Height
0.0433 in
Drilling & Strength Specs
Tap Drill Size
0.8875 in(22.54 mm)
Stress Area
0.6204 in²(400.27 mm²)
Quick Unit Converter
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Frequently Asked Questions
What is the tap drill size for 15/16-20 UNEF?
The recommended tap drill size for a 15/16-20 UNEF thread is 0.8875 inches (approx. 22.54 mm) to achieve standard thread engagement.
How many threads per inch (TPI) does a 15/16-20 UNEF bolt have?
A standard 15/16-20 UNEF thread has exactly 20 threads per inch (TPI), with a corresponding linear pitch of 0.05 inches.
What is the major diameter of a 15/16-20 UNEF thread in millimeters?
The nominal major diameter of a 15/16-20 UNEF thread is 0.9375 inches, which converts to 23.81 mm.