ISO 368:2017

Overview

ISO 368:2017 specifies the geometrical requirements for tubes used on ring‑spinning, doubling and twisting spindles in the textile industry. The standard covers tubes with taper 1:38 and 1:64, defining permitted inner diameters, lengths and total run‑out tolerances, plus the dimensions and tolerances for the gauges used to check those tubes. ISO 368:2017 replaces the previous edition and adds additional tube types and updated references.

Key topics and technical requirements

• Tube types: Two basic top styles are defined - Type A (plain top) and Type B (rolled‑in top) - with dimensional guidance illustrated in the standard.
• Tapers covered: Both 1:38 and 1:64 tapers are standardized for compatibility with ring‑spinning and twisting spindles.
• Dimensions and length rows: Inner diameters and lengths are specified in tabular form (rows for different lengths). Manufacturers select tube sizes from these standardized dimensions.
• Total run‑out tolerance (T): Permissible total run‑out values are given for each tube size and spindle speed class; measurement method is specified (see measuring arrangement in the document).
• Gauges: Dimensions and tolerances for gauges used to verify internal diameter at the base and top of the tube are provided, including use of short and long gauge parts for different checks.
• Designation rules: The standard prescribes a clear naming convention (for example: “Tube ISO 368 - 1:64 B - 230/2”), enabling unambiguous procurement and documentation.
• Reference to ISO 286‑2: Tolerance system for linear sizes is applied where relevant (ISO 286‑2).

Applications and who uses ISO 368:2017

• Textile machinery manufacturers use the standard to design and produce tubes that fit ring‑spinning, doubling and twisting spindles reliably.
• Spindle and component suppliers rely on the specified inner diameters, tapers and run‑out tolerances to ensure interchangeability and performance.
• Quality control and inspection teams use the gauge dimensions and measurement procedures to verify tube conformity on incoming parts and production lines.
• Maintenance and procurement professionals can reference the designation rules to order correct replacement tubes and gauges for textile plants.

Practical benefits include improved interchangeability of spindle tubes, predictable running behaviour (reduced vibration from controlled run‑out), and simplified inspection with standardized gauges.

Related standards

• ISO 286‑2 (Geometrical product specifications - ISO code system for tolerances on linear sizes) is referenced by ISO 368:2017 for hole/shaft tolerance classes.