Brass brazing Scott's frame no. 7018. OBCA tee shirt is mandatory garb for brazing bike frames with preform brass rings and a big hot torch. Air hardening Reynolds tubes gain strength as the frame cools to well in excess of the as delivered values. This unique air hardening property of Reynolds 853 and 631 tubing provides additional stiffness through reduced microyielding at the joints, allowing stiffer frames with excellent fatigue strength. This is why I continue to brass braze all Strawberry frames (braze-on's are silver brazed).