Overview
ISO 6743-1:2002 defines the classification system for Family A (Total loss systems) within Class L - Lubricants, industrial oils and related products. It establishes a coding scheme and product categories for lubricants intended for total-loss applications (where the lubricant is consumed or not recovered). This part is intended to be read with ISO 6743-99 (General) and references the ISO 3448 viscosity classification.
Key topics and requirements
- Detailed classification by code: Categories are designated by multi-letter symbols beginning with A (family identifier). The second letter groups product types (e.g., AY, AN, AB, AC).
- Product composition categories:
- AY: Mildly refined mineral oils for rough applications (axles, railway points). Note: some products may contain components harmful to health/environment.
- AN: Refined mineral oils for lightly loaded parts (rolling bearings, plain hydrodynamic bearings).
- AB: Refined mineral oils containing bitumen or additives to improve adhesiveness, extreme pressure or corrosion protection - used for open gears, wire ropes, chains.
- AC: Oils from mineral, animal, vegetable or synthetic origins with additives for specific properties (e.g., saw chains). Annex A indicates additional sub-categories for low-temperature operability, oxidation stability and environmental acceptability (toxicity, biodegradability).
- Viscosity designation: Categories AY, AN, AB are designated by ISO viscosity grades (VG) per ISO 3448 - e.g., ISO‑L‑AN 32 or L‑AN 32.
- Environmental/regulatory note: Products that may be directly discharged to the environment must comply with applicable national regulations.
- Scope limitations: Greases for some applications (open gears, wire ropes, exposed chains, bearings) may be used and are addressed separately.
Practical applications
- Classification and selection of lubricants for total-loss systems such as:
- Axles and railway switching points
- Open gears, wire ropes and cranes
- Chains (including saw chains and guide bars)
- Lightly loaded bearings and plain bearings in hydrodynamic regimes
- Useful for creating product datasheets, procurement specifications, maintenance schedules, and compliance assessments where lubricant recovery is not feasible.
Who uses this standard
- Lubricant manufacturers and formulators
- Equipment OEMs and designers specifying lubrication regimes
- Maintenance engineers and reliability teams
- Procurement and specification writers
- Regulatory and environmental compliance professionals
Related standards
- ISO 6743-99: Classification - General (must be read with Part 1)
- ISO 3448: Industrial liquid lubricants - ISO viscosity classification
- Other ISO 6743 parts: (F, D, H, T, C, M, R, X, Y, P, Q, G, U, E, etc.) for other lubricant families
- ISO 11679 (in development at time of publication): Specifications for saw chain and guide bar lubricants (referenced in Annex A)
Keywords: ISO 6743-1, Family A, total loss systems, lubricant classification, industrial oils, ISO viscosity, saw chain lubricants, open gear oil, chain oil, railway point lubrication, lubricant specifications, biodegradability.
Open preview (PDF)Lubricants, industrial oils and related products (class L) — Classification — Part 1: Family A (Total loss systems)