TPT July 2012

Scarf ing Tube scarfing systems and tools

Saw blades from Nap Gladu

The best proof of a successful scarfing operation is a tube that looks to be “as welded” rather than to have been scarfed at all; that is, it has a perfectly smooth surface and a weld zone practically indistinguishable from the parent material.

inserts used for scarfing the outside- diameter upset seam of a tube after welding – that have the fault (brittleness) of their essential virtue (hardness). Because so much is asked of these tools, considerable care must be taken with them: from proper coating and grinding and inspection for flaking or crazing, to raising the

insert when the weld passes and controlling vibration and deflection throughout the process. That scarfing tools perform as reliably as they do reflects an industrywide convention that even the smallest component merits outsize attention to its selection, preparation, and utilisation.

This achievement is largely the work of small ceramic tools – the