Unified inch screw threads are defined by which standard?

Unified inch screw threads are defined by which standard?

• A. ANSI B1.1
• B. ASME B31.5
• C. ASME B16.9
• D. ASME B16.34

Answer: (A)

Unified inch screw threads are defined by ANSI/ASME B1.1. This standard establishes the Unified Thread Standard for inch-series fasteners, covering the UNC and UNF thread forms, including their pitches, major and minor diameters, and tolerances to ensure interchangeability among manufacturers. The other standards refer to different parts of piping and equipment—B31.5 concerns alloy piping systems, B16.9 covers factory-made fittings, and B16.34 addresses valves and piping components—so they do not define the screw thread form.

Unified inch screw threads are defined by ANSI/ASME B1.1. This standard establishes the Unified Thread Standard for inch-series fasteners, covering the UNC and UNF thread forms, including their pitches, major and minor diameters, and tolerances to ensure interchangeability among manufacturers. The other standards refer to different parts of piping and equipment—B31.5 concerns alloy piping systems, B16.9 covers factory-made fittings, and B16.34 addresses valves and piping components—so they do not define the screw thread form.