Overview
ISO 4798:1997 specifies requirements and dimensional guidance for glass filter funnels intended for general laboratory use. The standard covers geometry, construction, material quality and marking to ensure compatibility with other general-use glassware such as boiling flasks and volumetric flasks. It supports consistent manufacturing and reliable performance across laboratory settings.
Keywords: ISO 4798, filter funnels, laboratory glassware, borosilicate glass, HGB3, dimensions, marking
Key Topics
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Types and sizes
- Plain filter funnels: bowl diameters listed include 35, 55, 75, 100, 125, 150 and 200 mm.
- Analytical filter funnels: bowl diameters listed include 55, 75 and 100 mm.
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Material requirements
- Glass shall comply with the hydrolytic resistance classification of class HGB3 or better as tested per ISO 719.
- Glass must be free from visible defects and internal stress that would impair funnel performance.
- At the manufacturer's discretion, funnels may be made from borosilicate glass 3.3 in accordance with ISO 3585.
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Construction and design
- Funnels consist of a bowl shaped as a right circular cone and a coaxial stem.
- The bowl wall diverges from the axis to give an included angle of approximately 60°.
- Rim options include fire-polished, beaded or ground-to-plane finishes; rim beads must not interfere with filter paper seating.
- Stem construction differs by type: plain funnels may have stems drawn from the bowl or fitted tubing; analytical funnels use a separate, securely joined tubing stem.
- The end of the stem shall be ground at a minimum angle of 30° to the axis, with the outer edge bevelled or fire-polished.
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Marking
- Mandatory markings: manufacturer/supplier name or mark and type of glass (if not otherwise identifiable).
- Optional markings: bowl internal diameter and the ISO 4798 standard number.
Applications
ISO 4798 filter funnels are intended for routine and analytical filtration tasks in chemistry, biology and quality control laboratories. Benefits include:
- Consistent interchangeability with other general-purpose glassware.
- Predictable mechanical and chemical performance when manufactured to specified material classes.
- Clear marking for traceability and material identification.
Typical uses: gravity filtration, sample preparation, routine separations and general laboratory workflows requiring standardized glassware.
Related Standards
Annex A and the normative references list additional standards relevant to laboratory glassware and materials. Key related standards cited in ISO 4798:1997 include:
These related standards support material classification, joint interchangeability and broader laboratory glassware design principles to ensure safe and compatible laboratory equipment.