Reynolds has launched a new stainless steel tube-set, 921, to complement our premium maraging super steel 953 and precipitation-hardening 931.
921 is cold-worked to a tensile strength of over 1000 MPa, similar that of heat-treated chrome-moly steels. This butting and/or swaging makes 921 probably the highest strength cold –worked tube set in the bike industry.
The US-sourced raw material is based on 21% Chromium, 6 % Nickel and 9% Manganese and is extensively used in the aviation industry under the name “21-6-9” for highly stressed hydraulic lines and aircraft components. It is also used in the marine, oil and gas industries due to its’ high corrosion resistance . Weldable and ductile, the first UK-made road frame using 921 has already passed the EN14781 frame fatigue test.
Why it works:
High chromium helps formation of a rust-preventing surface chrome oxide layer (stopping corrosion of the metal). Nickel and manganese aid toughness, and this alloy has a high nitrogen content which increases the yield strength.
As with all steels (ferrous and stainless), the stiffness modulus is high, allowing the use of small diameter tubes that can provide stiffness in a frame in other materials like aluminium or titanium.
Tube dimensions can be similar to our 631 and 725 range – and because this is a cold-worked tube set with good ductility, it offers offer shaping options when creating custom frames. 921 is suitable for use in lugged and TIG welded frames, with road, BMX, touring, cyclo-cross, hybrid and mountain bike design options possible because the wall thickness can be varied from 0.5mm up to 1.2mm.
Highly durable, corrosion resistant and with the “ride of steel”.
Reynolds will also be making tubing for engineering applications in long lengths.
Click here to download a metal alloys comparison (extract) PDF for designers.