Reynolds 520 – Cr-Mo

20 is the entry level chrome-moly tube set 15 from Reynolds. It is made in Taiwan. It contains 0.3% of carbon which is the same as 631 and 725 series Reynolds tube sets. Chromium increases hardness and oxidation resistance.
Molybdenum and Chromium together enhances tube strength. 520 is vastly applied in racing car chassis, motorcycle and bicycle frames. The strength and ductility of the tube vary according to the cold work processes undergone.