#4-48 UNF Thread Specs
Standard: ASME B1.1 (UNF)
Find the technical dimensions, threads per inch (TPI), and tapping guidelines for the #4-48 UNF unified thread.
Compliant with the ASME B1.1 standard, this size has a nominal major diameter of 0.112 inches (2.84 mm) with a pitch of 0.02083 inches (TPI of 48).
For general engineering or fastening, the standard recommended tap drill is 0.0912 inches (2.32 mm) to achieve adequate thread engagement.
Dimensional Specifications (Inches & mm)
Size Designation
#4-48 UNF
Major Diameter (Nominal)
0.112 in(2.84 mm)
TPI (Threads per Inch)
48
Pitch
0.02083 in
Pitch Diameter
0.0985 in(2.5 mm)
Minor Diameter (Ext)
0.0894 in(2.27 mm)
Minor Diameter (Int)
0.0917 in(2.33 mm)
Thread Height
0.018 in
Drilling & Strength Specs
Tap Drill Size
0.0912 in(2.32 mm)
Stress Area
0.0066 in²(4.26 mm²)
Quick Unit Converter
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Frequently Asked Questions
What is the tap drill size for #4-48 UNF?
The recommended tap drill size for a #4-48 UNF thread is 0.0912 inches (approx. 2.32 mm) to achieve standard thread engagement.
How many threads per inch (TPI) does a #4-48 UNF bolt have?
A standard #4-48 UNF thread has exactly 48 threads per inch (TPI), with a corresponding linear pitch of 0.02083 inches.
What is the major diameter of a #4-48 UNF thread in millimeters?
The nominal major diameter of a #4-48 UNF thread is 0.112 inches, which converts to 2.84 mm.