Secure your sub-frame to your main frame using this Triumph swingarm spindle bolt. Bolt is made in England to replace Triumph part number 21-0579, 21-759, S0579 and S579. Features a hole for a grease / zerk fitting and measures 5/8" X 18 TPI X 1 1/4 (UNF). Fits various Triumph 350 and 500 models (T90, T100, Daytona, etc) from approx 1967-1974 on the drive side. Please refer to your parts catalog to ensure the best fitment.