Quality Magazine

Large-Diameter Locknuts

January 2, 2008


Eight-pitch, large-diameter locknuts are available that meet the locking torque requirements of NASM-25027 (formerly MIL-N-25027). Developed originally for the petroleum industry, these one-piece, all-metal locknuts offer vibration- resistance without the excessive wrenching torques needed to tighten nuts with more threads per inch. Sizes from 1-inch diameter to 2½-inch diameter are available in carbon steel or corrosion-resistant austenitic steel. Cadmium plating to QQ-P-416 and silver plating per AMS 2410 are applied at the company’s in-house computer-controlled plating facility. Every thread in the one-piece design carries a portion of the induced load, allowing these locknuts to offer reliability under the severe conditions experienced by heavy drilling and pumping equipment.