ISO 12925-1:2018 establishes the specifications relative to family C (gears) for lubricants, industrial oils and related products of Class L (see ISO 6743‑6). This document deals only with lubricants for enclosed gear systems. Lubricants for open gears and greases for gears (enclosed or open) are not covered.
ISO 12925-1:2018 can be read in conjunction with ISO 6743‑6. The following categories specified in ISO 6743‑6 are covered by this document: CKB, CKC, CKD, CKE, CKSMP, CKTG, CKES, CKPG, CKPR.