Lubrication fundamentals: graphite, water-based, synthetics, and what's actually in the drum

The TDS (technical data sheet) is the supplier's performance pitch. Viscosity, density, recommended dilution, recommended application method, typical use cases. It is useful and it is also marketing-adjacent. The SDS (safety data sheet) is the regulatory document. It is required by OSHA Hazard Communication, REACH, and GHS, and the supplier has to disclose every hazardous component above the regulatory cutoff (typically 1% or 0.1% for carcinogens) by chemical identity or CAS number with a weight percent range.

For a forge lube the SDS sections that matter are section 3 (composition), section 9 (physical and chemical properties), and section 10 (stability and reactivity). Section 3 lists the active solid (graphite, hBN, MoS₂) and discloses the surfactant family, the corrosion inhibitor family, and any extreme-pressure additive. Section 9 confirms the carrier identity and gives the flash point and pH. Section 10 flags incompatibilities, which is where chlorinated additives and reactive surfactants show up.

Read the two documents together. A TDS that claims "advanced lubricity package" and an SDS that lists chlorinated paraffin in the same drum is telling you the lubricity package is a chlorinated EP additive, which is effective on steel-on-steel cold-work tribology and aggressive against any nitrided compound layer in the heat of a forge cycle. A TDS that claims "high-performance corrosion inhibition" and an SDS that lists alkyl amines is telling you the corrosion inhibitor is amine-based, which works on bare carbon steel and attacks ε-phase iron nitride on a nitrided die. The TDS will not say this. The SDS will, indirectly, by listing the chemistry.

A useful practice for any forge shop running nitrided tooling: pull the SDS for every lube in the lube room, photocopy section 3, and have the metallurgist or the heat-treat house cross-check the listed surfactant and EP additive families against the substrate treatment. The check is twenty minutes per drum and it surfaces incompatibilities that no operator will catch by reading the brand name.