A great tool for removing weld seams from tubing

A typical induction-welded or electric-resistance-welded (ERW) tube has weld beads on the ID and OD. A scarfing tool can remove the OD weld bead.

The life expectancy of a seemingly insignificant dollars scarfing insert can reveal the company's underlying attitude, pride, determination, and resourcefulness, or it can show that these are lacking. Long scarf tool life is a direct reflection of quality mill maintenance, tooling setup, slitting practices, and attention to detail. Operations with long scarfing tool life are success stories.

Before we discuss extending scarfing tool life, I should mention where scarfing tools are used. Nearly every welded tube mill employs a scarfing tool to remove the OD weld bead created by the forge-welding process . The purpose of removing the weld bead is to leave a perfectly smooth surface; the weld zone should be visually indistinguishable from the parent material. It should be noted that some welded tube is sold as welded, which is not scarfed.

Improper application can cause premature insert failure. Improper applications include using an insert with a holder that does not match the relief angle or using an insert that has a radius that is too small for the tube being scarfed. Do you try to cut corners by using flat inserts or radiused inserts for ODs other than intended?

Improperly mounting the tool or improperly applying the tool to the work can cause inserts to fail. The biggest mistake here is using the wrong hand tools to assemble, install, adjust, and engage the welded tube bead. I have seen line and supervisory personnel use hammers, prybars, bigger hammers, T-wrench persuasion (using a T-wrench to hammer, rather than tighten, a fastener), and other imaginative tools to get the job done.

Do you provide the proper tools, such as leather-faced or other types of dead-blow hammers to seat the inserts or loosen lockdown hardware? Do you supply the proper hand tools, such as wrenches and Allen keys, and new socket head cap screws for the line operators to install the scarfing tools?

How do you monitor material quality? This is perhaps the most difficult problem because of time constraints. "We have to run it, the customer is waiting" sums up one condition all tube manufacturers face. Replacing broken scarfing tools is a small cost of doing business but a big indicator of how well a manufacturer performs in other areas, such as good material buying, slitting setups, and quality control.