Minor Diameter
Definition
The smallest diameter of a screw thread, measured at the root (bottom) of the external thread or the crest of the internal thread. This dimension is critical for thread strength calculations.
Practical Note
Tap drill size is typically based on minor diameter plus some allowance for chip clearance. Thread tensile stress area uses a diameter between minor and pitch diameter.
Related Calculators
🔩Screw Size Chart
Interactive screw size reference. Look up major diameter, minor diameter, thread pitch, tap drill size, and clearance hole for machine screws in UNC, UNF, and metric standards.
🔧Bolt Size Chart
Interactive bolt size reference. Look up head dimensions, thread specifications, recommended hole sizes, and matching nut dimensions for hex bolts in SAE and metric standards.