#8-36 UNF Thread Specs
Standard: ASME B1.1 (UNF)
Find the technical dimensions, threads per inch (TPI), and tapping guidelines for the #8-36 UNF unified thread.
Compliant with the ASME B1.1 standard, this size has a nominal major diameter of 0.164 inches (4.17 mm) with a pitch of 0.02778 inches (TPI of 36).
For general engineering or fastening, the standard recommended tap drill is 0.1362 inches (3.46 mm) to achieve adequate thread engagement.
Dimensional Specifications (Inches & mm)
Size Designation
#8-36 UNF
Major Diameter (Nominal)
0.164 in(4.17 mm)
TPI (Threads per Inch)
36
Pitch
0.02778 in
Pitch Diameter
0.146 in(3.71 mm)
Minor Diameter (Ext)
0.1339 in(3.4 mm)
Minor Diameter (Int)
0.1369 in(3.48 mm)
Thread Height
0.0241 in
Drilling & Strength Specs
Tap Drill Size
0.1362 in(3.46 mm)
Stress Area
0.0147 in²(9.5 mm²)
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Frequently Asked Questions
What is the tap drill size for #8-36 UNF?
The recommended tap drill size for a #8-36 UNF thread is 0.1362 inches (approx. 3.46 mm) to achieve standard thread engagement.
How many threads per inch (TPI) does a #8-36 UNF bolt have?
A standard #8-36 UNF thread has exactly 36 threads per inch (TPI), with a corresponding linear pitch of 0.02778 inches.
What is the major diameter of a #8-36 UNF thread in millimeters?
The nominal major diameter of a #8-36 UNF thread is 0.164 inches, which converts to 4.17 mm.