Overview
ISO 8188:2007 - Textile machinery and accessories - Pitches of knitting machines - is an international standard that specifies how to define, measure and designate the pitches (needle spacings) and gauges of knitting machines used across the textile industry. This second edition (2007) replaces the 1986 edition and provides standardized definitions, measurement methods and reference pitch/gauge tables for both flat and circular knitting machines.
Key topics and technical requirements
- Definitions: Clear terms for pitch (t - distance between centres of adjacent needles) and gauge (number of needles per reference length).
- Gauge reference systems:
- Gauge E - number of needles per 25.4 mm.
- Gauge F - number of needles per 25.0 mm.
- Measurement methods:
- Flat knitting machines - pitch determined by measuring centreline spacing of two adjacent needles in the needle carrier (needle bar/bed).
- Circular knitting machines - pitch calculated using the formula t = (d × π) / n_max, where d is the nominal diameter (mm) and n_max is the maximum number of needles in the needle carrier.
- Reference tables: The standard includes Tables 1 and 2 listing standard pitch-to-gauge relationships for common gauges (E and F). For circular machines, the listed values are guide values because construction-dependent deviations may occur.
- Notation and commercial designation: Gauge is denoted as E or F plus the gauge number (e.g., E14). For circular machines, commercial references to pitch or gauge should also specify the total number of needles in the needle carrier.
- Normative reference: ISO 7839 (Knitting machines - Vocabulary and classification) is referenced for related terms and classification.
Applications and who uses this standard
ISO 8188:2007 is intended for:
- Knitting machine manufacturers - to design and label machines with standardized pitch/gauge data.
- Textile engineers and technologists - for machine selection, fabric design and process setup.
- Procurement and specification authors - to write clear equipment specifications and ensure compatibility between machines, needles and accessories.
- Quality control and testing labs - to verify that needle spacing and gauge conform to standard values.
- Suppliers and buyers - to communicate machine capabilities and ensure interchangeability of components.
Practical uses include machine design, spare-part compatibility checks, production planning, and accurate commercial descriptions in purchase orders.
Related standards
- ISO 7839 - Textile machinery and accessories: Knitting machines - Vocabulary and classification (normative reference used by ISO 8188:2007).
Keywords: ISO 8188:2007, knitting machine pitch, machine gauge, needle spacing, flat knitting machines, circular knitting machines, textile machinery standard.
