Overview
EN ISO 4803:2023 - Laboratory glassware: Borosilicate glass tubing (ISO 4803:2021) is a CEN-adopted international standard specifying requirements for borosilicate 3.3 glass tubing used in laboratory apparatus. It covers tubing with outer diameters from 4 mm to 300 mm, defining designation, material properties, dimensional ranges, tolerances and inspection methods. The document is aligned with ISO 3585 (material) and refers to ISO 719 (hydrolytic resistance) and ISO 1101 (geometrical tolerancing).
Key topics and technical requirements
- Scope and designation
- Tubing is designated by glass type, outer diameter, wall thickness category (light / medium / heavy) and manufacturer.
- Material
- Tubing must conform to ISO 3585 borosilicate 3.3 requirements; free from harmful stresses and defects.
- Hydrolytic resistance
- Alkali extraction (tested per ISO 719) shall not exceed 31 μg Na2O/g.
- Thermal properties
- The glass has a very low coefficient of mean linear thermal expansion specified in the standard for the 20 °C to 300 °C range.
- Dimensions and tolerances
- Outer diameter, wall thickness, length, straightness and ovality tolerances are defined in tabulated form (Tables 1–3).
- Wall thickness difference (siding): max difference per cross-section is 12% of specified wall thickness (without exceeding wall thickness tolerance).
- Geometric inspection methods
- Outer diameter measured as largest distance in a plane perpendicular to the axis.
- Wall thickness measured as the shortest distance between inner and outer surfaces (specified measurement techniques given).
- Straightness: different test setups for 4–5 mm tubes (flat surface/stop) and ≥6 mm tubes (supported span and sag measurement).
- Ovality: tolerance up to 0.7% for diameters ≤48 mm and 1.0% for 50–300 mm (measured while rotating the tube).
Applications and users
- Practical for manufacturers of laboratory glassware, glass tubing suppliers, QA/QC engineers, laboratory equipment designers and procurement specialists.
- Common applications include chemical, pharmaceutical and food-industry laboratories and any technical use requiring high chemical resistance, thermal shock resistance and well-defined dimensional quality for glass tubing components.
Related standards
- ISO 3585 - Borosilicate glass 3.3 - Properties
- ISO 719 - Hydrolytic resistance test and classification
- ISO 1101 - Geometrical product specifications (ovality/circularity)
EN ISO 4803:2023 helps ensure consistent material performance and dimensional interchangeability for borosilicate laboratory tubing, supporting reliable manufacturing, testing and procurement of laboratory glassware.
