The DISC-LOCK Railcar Fastening System requires fewer laborers to install and reduces man power needs. Reduces laborer fatigue, which increases laborer efficiency; results in faster installation rates which increase over-all efficiency. Lowers costs through easy visual inspection with 100% inspection capability and through reusability with no performance degradation from repeated use. Provides greater reliability through preset tension and does not require tool calibration; eliminating operator error. Nuts do not vibrate loose in high vibration areas and can be removed without burning or cutting. DISC-LOCK Railcar Fastening Systems meet all AISC requirements and specifications of ASTM A325 and A490. Disk-Lock nuts meet all physical requirements of ASTM A194-2H.