Overview
ISO 2947:1973 - Textiles: Integrated conversion table for replacing traditional yarn numbers by rounded values in the Tex System - provides a practical, industry-focused conversion table to simplify the transition from a variety of traditional yarn numbering systems to the Tex unit of linear density. The standard gives recommended rounded Tex and decitex values that replace counts in the six main traditional systems so manufacturers, traders and users can adopt a common unit for yarn linear density.
Key topics
- Scope and purpose: Facilitates changeover from traditional yarn numbering systems to the Tex System for the majority of spun and filament yarns.
- Conversion table: An integrated table mapping traditional yarn counts to rounded Tex (and decitex) values covering the six main traditional systems (Cotton/English, Metric (Nm), Worsted, Linen, Jute and Denier).
- Rounding principle: Rounded Tex values are chosen to accommodate many traditional counts while avoiding undue encroachment on spinner tolerances; values are generally within about ±2% of the exact Tex equivalents.
- Choice of unit: Guidance on using tex for medium/coarse yarns and decitex (dtex) for fine yarns; decitex values are included to avoid decimal fractions across ranges.
- Application notes: Advice on fractional counts, special cases (e.g., carpet, tyre yarns), and exceptions such as sewing threads where tighter tolerances require bespoke agreements.
- References: Linked to ISO/R 1144 (universal system for designating linear density) as the basis for exact Tex equivalents.
Applications
- Standardizes yarn specification and labelling for procurement, production orders and technical data sheets.
- Simplifies international trade and communication by providing a common linear density unit (Tex/dtex) across markets that historically used differing counts.
- Supports production planning and machine setup, inventory control, and quality control where consistent linear density units are required.
- Useful for converting legacy product ranges and catalogs to Tex for product rationalization and rational intervals between linear densities.
Who should use this standard
- Spinners and yarn manufacturers transitioning product ranges to Tex.
- Textile mills, converters and fabric producers needing consistent yarn specifications.
- Quality engineers, product developers, procurement and standards teams operating across international supply chains.
- Standards bodies and technical committees working on harmonization of textile units.
Related standards
- ISO/R 1144 - Universal system for designating linear density (Tex) - used to compute exact Tex equivalents referenced in ISO 2947:1973.
Keywords: ISO 2947:1973, Tex System, textile standards, yarn numbering, conversion table, linear density, decitex, denier, cotton count, Nm, jute.
