Viscosity of ISO VG Viscosity Classifications – viscosity table and viscosity chart

Industrial fluids kinematic viscosity according to ISO 3448, DIN 51519

ISO-VG (Viscosity Grade) classes apply only for industrial lubricating oils. For engine oil check SAE J300 and SAE J306 for gear oils. A viscosity grades classification or standard known as the ISO VG (International Standards Organization Viscosity Grade). Settled in 1975 by a joint committee of International Standards Organization (ISO), American Society for Testing and Materials (ASTM), Society for Tribologists and Lubrication Engineers (STLE), British Standards Institute (BSI), and Deutsches Institute for Normung (DIN).

Lubricant viscosity performs a prime role against friction and wear. ISO viscosity classification system or ISO Viscosity grades also called ISO VG contains 18 viscosity grades. ISO VG are based on kinematic viscosity of the lube oil/fluid at 40°C. The ISO system is primarily used for hydraulic oil, industrial oils, such as turbine oils, compressor oils and others.

Viscosity table/chart as per ISO 3448 for industrial fluids.

ISO
viscosity grade
classifications
Midpoint
kinematic
viscosity, cSt
@40°C
Kinematic viscosity, cSt @40°C
Minimum Maximum
ISO VG 2 2.2 2.0 2.4
ISO VG 3 3.2 2.9 3.5
ISO VG 5 4.6 4.1 5.1
ISO VG 7 6.8 6.1 7.5
ISO VG 10 10 9.0 11.0
ISO VG 15 15 13.5 16.5
ISO VG 22 22 19.8 24.2
ISO VG 32 32 29.8  35.2
ISO VG 46 46 41.1 50.6
ISO VG 68 68 61.2 74.8
ISO VG 100 100 90.0 110
ISO VG 150 150 135 165
ISO VG 220 220 198 242
ISO VG 320 320 288 352
ISO VG 460 460 414 506
ISO VG 680 680 612 748
ISO VG 1000 1,000 900 1,100
ISO VG 1500 1,500 1,350 1,650
ISO VG 2200 2,200 1,980 2,420
ISO VG 3200 3,200 2,880 3,520

Viscosity grade numbers of the ISO are the same as those of ASTM (The American Society of Testing and Materials) and BSI (British Standards Institution), with the difference that the viscosities for the ISO grades are measured at 40 °C, while those of the ASTM and BSI are measured at 100 °F (37.8 °C). Lubricants of a given ASTM or BSI grade are slightly more viscous than lubricants of the corresponding ISO grade.