#0 screw or bolt dimensions and sizes are commonly used for precision electronics, optical instruments, and micro-mechanical assemblies. This size have a 0.060″ nominal major diameter and is most commonly specified with a #0-80 fine (UNF). with the 80 representing threads per inch (TPI). This reference chart follows ANSI/ASME B18.6.3 and B18.3 standards for the head size and ANSI/ASME B1.1 standards for the thread dimensions to ensure compatibility across imperial fastening applications.
Disclaimer: Dimensions and tolerances may vary slightly depending on head style, manufacturer, or material — always verify with the official product datasheet before use.
#0-80 UNF Screw & Bolt – ANSI/ASME B1.1
Dimension
Size (in)
Min
Max
Major Diameter
0.0563
0.0595
Pitch Diameter
0.0496
0.0514
Minor Diameter
Not specified
0.0446
Threads Per Inch (TPI)
80
Major Diameter
0.0568
0.06
Pitch Diameter
0.0506
0.0519
Minor Diameter
Not specified
0.0451
Threads Per Inch (TPI)
80
Major Diameter –
The largest diameter of the external thread, measured crest to crest.
This defines the nominal size of the screw or bolt.
Pitch Diameter –
The diameter of an imaginary cylinder where the thread thickness equals
the space between threads. This dimension primarily controls thread fit
and tolerance class of 2A and 3A.
Minor Diameter –
The smallest diameter of the external thread, measured root to root.
This affects thread strength and clearance.
Threads Per Inch (TPI) –
The number of complete threads within one inch of thread length.
Higher TPI values indicate a finer thread pitch.
What is the tap drill size for a #0-80 screw or bolt?
The appropriate tap drill depends on the material being threaded. For aluminum, brass, or plastic (75% thread), a 3/64″ (0.047″) drill bit is specified. For steel, stainless, or iron (50% thread), a #55 (0.052″) drill bit is recommended to reduce torque on the tap.
What clearance hole size is needed for a #0 screw or bolt?
For a Close Fit, a #52 (0.064″) drill bit is utilized. For a Free Fit (standard clearance), a #50 (0.070″) drill bit is used to allow the fastener body to pass through without interference.
What is the difference between a bolt and a screw?
The difference is based on the intent of the fastener’s use; If the primary intent is for the fastener to pass through an unthreaded holes and be assembled with a nut, it is a Bolt. In this application, you usually hold the head and turn the nut to apply tension. But if the primary intent is for the fastener to be installed into a threaded (tapped) hole, it is a Screw. In this application, the connection is tightened by turning the head of the fastener itself.
