Framebuilders - Suitability of Reynolds 631 to fillet brazing?

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mudboy
04-24-10, 11:53 AM
I'm about to build my first fillet brazed mountain bike frame (sloping top tube hardtail) and was considering using Reynolds 631 OS from Strawberry. I'll be using brass (though I can use silver if necessary). How suitable is this tubeset to fillet brazing, i.e. does it have shorter butts that are only good for TIG welding, or should it be OK for fillet?

Thanks,

Pete

Scooper
04-24-10, 05:43 PM
Reynolds claims 631 is suitable for fillet brazing.

http://reynoldstechnology.biz/our_materials_631.php

"631 SEAMLESS AIR-HARDENING HEAT-TREATED STEEL

Utilising the same chemistry as 853, this product 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.

631 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."

Dave Kirk won "Best Fillet Brazed" at NAHBS this year using Reynolds 725.