Utilising the same chemistry as 853, Reynolds 631 is cold-worked and also has the advantages of air-hardening after welding. The alloy is a development on our famous 531 range with 10% higher strength. For cycling use, this provides tough, durable and comfortable frames particularly suitable for long distance riding, ATB and BMX . It has recently become available for touring and race fork blades.
It can also be used for sports car chassis, suspension units, motorcycle race frames etc. in welded and fillet-brazed structures. In most applications, it should not be necessary to stress-relieve the weld zone.
Why Reynolds 631 works:
UTS: 800-900 MPa, density 7.78 gm/cc.
As 853 in composition but tube strength results from the extensive cold-working of the seamless billet without a final heat-treatment. The TIG welded part of the tube still benefits from the air-hardening feature that results in a fine grain structure within the heat-affected zone.
How you would use it:
631s properties lend it to making frames with highly shaped tubes, with the air hardening qualities in the weld zone allowing thinner lighter tubes. The outcome is a supple comfortable ride with no weight penalty. The wide range of tube sizes and shapes allows frame designers considerable freedom.
Click here to download a metal alloys comparison (extract) PDF for designers.