Overview
ISO 19259:2021 - "Plain bearings - Bearings with embedded solid lubricants" defines design and application guidance for plain bearings that incorporate solid lubricant plugs or inserts in a metallic base. This second edition (2021) updates the 2015 edition and focuses on the widely used plug-type embedded solid-lubricant bushings (cylindrical and flanged bushes). The standard covers structure, materials, friction/wear behavior, dimensions, assembly and surface-finish considerations, with informative annexes for selection and application examples.
Key topics and technical requirements
- Bearing structure: Describes embedded lubricant configurations - plug type and spiral type, with hole variants as through (perforated) or bottomed holes. Typical forms covered are cylindrical bushes and flanged bushes.
- Friction and wear characteristics: Classifies embedded solid-lubricant bearings within self-lubricating bearings and explains their lubrication mechanism - lubricant is drawn from embedded plugs to form/repair a lubricating film, enabling long life and operation without external oil in many cases.
- Materials:
- Metallic base bodies: Recommended materials include high-strength cast brass, cast bronze, aluminium bronze and grey cast iron (ISO 185 referenced).
- Solid lubricants: Typical types are graphite-based (general/high-temperature use), fluororesin-based (general/underwater use), and specialty sulfide types (e.g., molybdenum or tungsten disulfide) for extreme conditions. The standard notes manufacturing/fixing methods for plugs (adhesive, press-fit, injection and solidification).
- Combination and selection guidance: Tables and guidance show typical metal–lubricant pairings and suitability by load, environment (freshwater, seawater), and temperature.
- Dimensions and manufacturing: Preferred nominal inside/outside diameters, widths and flange dimensions are provided for common sizes. The standard emphasizes minimum wall thickness to retain lubricant plugs and details surface-finish and assembly considerations.
- Normative and informative content: Includes normative reference to ISO 185 and informative annexes - Annex A (selection guide) and Annex B (actual applications).
Practical applications and users
- Applications: Ideal for rotational, reciprocating, oscillating and frequent start/stop motions; particularly where fluid lubrication is impractical (high load/low speed, high temperature, underwater or corrosive environments).
- Who uses this standard:
- Bearing designers and manufacturers specifying embedded solid-lubricant bushings
- Mechanical design and maintenance engineers selecting self-lubricating solutions
- Procurement and quality teams verifying dimensions and material conformity
- Standards bodies and testers referencing dimensional and material requirements
Related standards and SEO keywords
- Related: ISO 185 (Grey cast irons). Useful keywords to find this content: ISO 19259:2021, plain bearings, embedded solid lubricants, self-lubricating bearings, graphite-based lubricant bushings, fluororesin bushings, flanged bush dimensions, bearing material selection.
