The ROYCO 586M is a mineral-based extreme-pressure (EP) gear lubricating oil qualified to MIL-PRF-6086 Grade M, designed for heavily loaded, low-to-moderate speed gear systems such as helicopter gearboxes and aviation accessory gear trains.

It is part of the Royco 586 series, formulated with highly refined mineral oils and additive packages to provide oxidation resistance, corrosion protection, anti-foam performance, and stable viscosity over a wide temperature range.

Key features include:

MIL-PRF-6086 Grade M qualified gear oil
Mineral-based EP lubricant for aviation gear systems
High load-carrying capability (anti-scuff protection)
Excellent oxidation and corrosion resistance
Anti-foam and air-release performance
Stable viscosity in moderate-to-warm operating climates
Suitable for helicopter gearboxes and accessory drives
Designed for low–medium speed, high-torque gear contact
Good thermal stability for continuous operation
NATO equivalent codes: O-153 / O-155 (depending on grade)