ASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence.
D-445 determines an oil’s viscosity of fluidity at a specific temperature. At the same temperature, a light ISO 32 oil has a lower viscosity than a heavier ISO 150 oil. When the temperature changes, the viscosity of each oil will change. When an oil’s temperature increases it becomes more fluid, or thinner; When it temperature drops it becomes less fluid, or thicker. The oil temperature must always be given when reporting a viscosity. The three most common temperatures used to report viscosities are 40ºC, 100ºC and the oil’s operating temperature. Oil viscosity is expressed in either SUS (Saybolt Universal Seconds) or in cSt (centistokes). Centistoke viscosity is an international standard and is more widely used.
D-92 - Standard Test Method for Flash and Fire Points by Cleveland Open Cup Tester.
D-4052 - Standard Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter.
D-664 - Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration.
D-1401 - Standard Test Method for Water Separability of Petroleum Oils and Synthetic Fluids
D-892 test is used to determine the foam tendency of a gear oil. The test is run in three sequences. Each sequence measures foam 1) after blowing air through the oil for 5 minutes and 2) after the oil settles 10 minutes after blowing. Sequence I cools oil from 120ÚF to 75ÚF to represent oil foaming at startup temperature. Sequence II keeps the oil at 200ÚF to represent oil foaming at operating temperature. Sequence III cools sequence II oil to 75ÚF to represent oil foaming during shutdown. AGMA gives a pass to all oils that: Have a maximum of 75 ml of foam immediately after blowing for 5 minutes; Have a maximum of 10 ml of foam after allowing the oil to settle for 10 minutes.
D-130 is normally run at 212ºF, but to make the test more severe AGMA increased the temperature to 250ºF. ASTM D-130 is used to determine the corrosiveness of a gear oil’s EP additive to nonferrous metals. A polished copper strip is immersed in the 250ºF oil bath for three hours and the EP additive corrosiveness is determined by comparing the strip against ASTM pre-rated strips.
D-665 rust test is used by AGMA to determine a gear oil’s ability to protect ferrous metals from rust in both fresh and saltwater environments.
D-2893 is a “dry air oxidation test” for EP gear oils only. The test normally is run for 13 days at 203ºF. To make the test more severe, AGMA increased the test temperature to 250ºF. A test temperature of 250ºF instead of 203ºF is more severe because the rate of oil oxidation doubles with every 18ºF increase in temperature. A gear oil that is oxidation stable in this 250ºF test will be more oxidation stable at the relatively low gear box temperatures of 140ºF to 180ºF. Gear oils that are oxidation stable reduce the frequency of oil changes, resulting in significant dollar savings to the user. The advanced oxidation stability of Royal Purple’s oil can increase oil drain intervals up to 15,000 hours. This is six times longer than AGMA’s recommended 2,500 hours oil change interval.