ISO 3371:1975

Overview

ISO 3371:1975 specifies envelope dimensions for rotary tables and multi‑sided centre bases used in special‑purpose machines constructed from modular units. The standard provides dimensional tables and basic locating methods to ensure compatible mechanical interfaces when integrating rotary indexing elements into modular machine‑tool assemblies.

Key topics and requirements

• Scope: Dimensions are confined to rotary tables and multi‑sided centre bases intended for modular machine‑tool construction.
• Dimensional tables: The standard includes two principal tables:
  • Table 1: Dimensions for multi‑sided centre bases (given in millimetres).
  • Table 2: Dimensions for workpiece rotary tables, including table diameters and heights; also shows provisions such as swarf‑tray positions.
• Location/fit methods: Multi‑sided centre bases are located on wing bases using tenon-and-slot connections or dowels, as specified.
• Notes on sizes: ISO 3371 lists specific nominal sizes (examples in the standard cover diameters from the low hundreds of millimetres up to around 2 000 mm) and flag certain values that should be avoided where possible.

Applications

ISO 3371 is practical for:

• Machine-tool and special‑purpose machine designers specifying modular construction using standard rotary units.
• Manufacturers of rotary tables, centre bases, and modular fixtures who need to supply compatible envelope dimensions.
• System integrators and automation engineers creating modular cells where interchangeability and repeatable mechanical location are required.
• CAD library and tooling teams standardizing part families and ensuring consistent mounting interfaces across suppliers.

Using ISO 3371 helps reduce custom interface engineering, speeds up machine assembly, and improves interchangeability of rotary units across different machine frames and vendors.

Related standards

• Other ISO standards and technical committee outputs on machine tools (ISO/TC 39), modular construction and component interfacing are often used in conjunction with ISO 3371 to cover tolerances, performance, and safety requirements.
• When implementing ISO 3371 in product design or procurement, consider complementary standards that specify accuracy, clamping interfaces, and spindle/drive interfaces for rotary indexing units.

By adopting ISO 3371:1975, manufacturers and designers align on common envelope dimensions and locating practices for rotary tables and multi‑sided centre bases, simplifying modular machine-tool construction and supplier interoperability.