9/16-12 UNC Thread Specs
Standard: ASME B1.1 (UNC)
Find the technical dimensions, threads per inch (TPI), and tapping guidelines for the 9/16-12 UNC unified thread.
Compliant with the ASME B1.1 standard, this size has a nominal major diameter of 0.5625 inches (14.29 mm) with a pitch of 0.08333 inches (TPI of 12).
For general engineering or fastening, the standard recommended tap drill is 0.4792 inches (12.17 mm) to achieve adequate thread engagement.
Dimensional Specifications (Inches & mm)
Size Designation
9/16-12 UNC
Major Diameter (Nominal)
0.5625 in(14.29 mm)
TPI (Threads per Inch)
12
Pitch
0.08333 in
Pitch Diameter
0.5084 in(12.91 mm)
Minor Diameter (Ext)
0.4723 in(12 mm)
Minor Diameter (Int)
0.4813 in(12.23 mm)
Thread Height
0.0722 in
Drilling & Strength Specs
Tap Drill Size
0.4792 in(12.17 mm)
Stress Area
0.1819 in²(117.38 mm²)
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Frequently Asked Questions
What is the tap drill size for 9/16-12 UNC?
The recommended tap drill size for a 9/16-12 UNC thread is 0.4792 inches (approx. 12.17 mm) to achieve standard thread engagement.
How many threads per inch (TPI) does a 9/16-12 UNC bolt have?
A standard 9/16-12 UNC thread has exactly 12 threads per inch (TPI), with a corresponding linear pitch of 0.08333 inches.
What is the major diameter of a 9/16-12 UNC thread in millimeters?
The nominal major diameter of a 9/16-12 UNC thread is 0.5625 inches, which converts to 14.29 mm.