The laboratory wear testing capabilities of the Bureau of Mines are described. Wear tests are used to support the Bureau's research efforts toward reducing the wear of equipment used for mining and minerals processing and any wear involving a loss of strategic or critical materials. The emphasis is on abrasive wear because it accounts for most of the wear losses that occur in mining and minerals processing equipment. Spalling wear, caused by repetitive impact in grinding equipment, also is included. Ten abrasive wear tests, including high-stress and low-stress and two-body and three- body conditions, are described: dry-sand, rubber-wheel abrasive wear; taber abraser; abrasion resistance of refractory materials; dry-particle erosive wear; elevated-temperature, dry-particle erosive wear; low-angle slurry pot; jaw crusher gouging wear; ball mill wear; pin-on-drum abrasive wear; and high-speed impact gouging. Two repetitive impact tests are described: ball-on-block impact- spalling and ball-on-ball impact-spalling. Test equipment, procedures, and specimens are described, and typical test results are presented and discussed.