The ETBB39 is a low-profile tungsten bucking bar, thin enough to slip into shallow gaps while still carrying real backing mass. It measures 3.75 inches long by 0.75 inches wide by 0.313 inches thick and weighs 0.6 lbs. It suits small-diameter rivets, thin trim, and delicate spots where a heavier bar would be hard to control.

Tungsten’s high density concentrates the backing mass, so the bar pushes back on the rivet gun like something larger. In a cramped bay that means less bar to hold and position, a steadier rebound behind the rivet set, and less hand and wrist fatigue over a long session.

This bar is produced in the USA from dense tungsten alloy and hand finished so the faces will not scuff your workpiece. It is a dependable pick for aircraft assembly and repair, restoration and experimental builds, and any solid rivet work where control and access matter.

To be sure this is the right bar for your rivet pattern, USA Tungsten publishes the matching product page with every dimension, and the bucking bar selector tool can help you compare it against other sizes and shapes.

Frequently asked questions

What jobs is the ETBB39 bucking bar best for?

It is a low-profile bar at 0.6 lbs and 3.75 by 0.75 by 0.313 inches. It suits small-diameter rivets, thin trim, and delicate spots where a heavier bar would be hard to control.

How is a tungsten bucking bar better than steel?

Tungsten's high density concentrates the backing mass, so the bar pushes back on the rivet gun like something larger. You get the backing mass you need without a heavy, bulky steel bar to wrestle.

Is the ETBB39 made in the USA?

Yes. It is machined in the United States from high density tungsten alloy and finished so the working faces will not scuff aluminum skin.