AGMA Standard Specification 250.04

Lubrication of Industrial Enclosed Gear Drives
Rust and Oxidation Inhibited Gear OilsViscosity Range (a)Equivalent ISO Grade (a)Extreme Pressure Gear Lubricants (b)
AGMA Lubricant No.cSt(mm2/s) at 40oC AGMA
141.4 to 50.646-
261.2 to 74.8682 EP
390 to 1101003 EP
4135 to 1651504 EP
5198 to 2422205 EP
6288 to 3523206 EP
7 Comp(c)414 to 5064607 EP
8 Comp(c)612 to 7486808 EP
8A Comp(c)900 to 110010008A EP
(a) "Industrial Liquid Lubricants - ISO Viscosity Classification." International Standard, ISO 3448. Also ASTM D2422 and British Standards Institution BS 4231.   
(b) Extreme pressure lubricants should be used only when recommended by the gear drive manufacturer.   
(c) Oils marked Comp are compounded with 3% to 10% fatty or synthetic fatty oils.