ASTM D4998 Standard Test Method for Evaluating Wear Characteristics of Tractor Hydraulic Fluids
1. Scope
1.1 This test method is used to screen lubricants for gear wear. It is primarily applicable to tractor hydraulic fluids but may be suitable for other applications.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific warning information is given in Sections 7 and 9.
2. Referenced Documents
2.1 ASTM Standards:
D235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)
D323 Test Method for Vapor Pressure of Petroleum Products (Reid Method)
D329 Specification for Acetone
D4175 Terminology Relating to Petroleum, Petroleum Products, and Lubricants
2.2 Deutsches Institut fur Normung (DIN):
DIN 17210 Part 1: Tolerances for Spur Gears; Tolerances for the Deviation of Singly Determined Values
DIN 3962 Casehardened Steel; Material Specifications
DIN 50150 Testing of Steel and Cast Steel Conversion Table for Vickers Hardness, Brinell Hardness, Rockwell Hardness and Tensile Strength
DIN 51354 Mechanical Testing of Gear Oils in the FZG Gear Test Machine
3. Terminology
3.1 Definitions:
3.1.1 abrasive wear, n - wear due to hard particles or hard protuberances forced against and moving along a solid surface.
3.1.2 scoring, n - in tribology, a severe form of wear characterized by the formation of extensive grooves and scratches in the direction of sliding.
3.1.3 scratches, n - the result of mechanical removal or displacement, or both, of material from a surface by the action of abrasive particles or protuberances sliding across the surfaces.
3.1.4 scuffing, n - in lubrication, damage caused by instantaneous localized welding between surfaces in relative motion that does not result in immobilization of the parts.
3.2 Definitions ofTerms Specific to This Standard:
3.2.1 wear, n - the loss of material from contacting surfaces of the gear teeth.
