What to copy from the marking
Keep the nominal diameter, pitch or TPI, system, internal/external designation and class together. A bare “2” or “6” is incomplete.
Use the maintained class guide
The thread-tolerance guide explains the supported Unified and metric class notation. Class-specific acceptance limits require the applicable standard and exact size; the nominal-dimension calculator does not supply those limits.
Continue your task
Sources and review scope
Reviewed 23 October 2026. Arithmetic examples are labelled separately from source-table facts and standard scope.
ASME B1.1-2024
Official catalogue for Unified inch threads; public scope and edition only, no class-specific table reproduced.
Open the original source ↗ISO 965-1:2026
Published April 2026; public scope of the general-purpose metric thread tolerance system.
Open the original source ↗