Tom Moeller, 28th Maintenance Squadron precision measurement equipment lab technician, calibrates a torque wrench using a multitest torque, force and angle testing machine at their lab on Ellsworth Air Force Base, S.D., Feb. 20, 2013. Torque wrench calibration ensure fasteners meet exact tension specifications to function safely. (U.S. Air Force photo by Airman 1st Class Anania Tekurio/Released)