We manufactured the original U hangers with 16-gauge galvanized steel. In 1959, we created the heavy-duty HU hangers from 1/8″-thick steel angles and a gray primer coat. The HU hangers were available with and without top flanges.

In 1969, we changed from using 1/8″-thick steel angles to 12-gauge galvanized sheet steel. We also added the option to conceal the face flanges for a cleaner look. The change to galvanized sheet steel saved cost by eliminating paint.

On the first day of trivia, I talked about the first A35 being square and the subsequent modifications to that created a more efficient cookie-cut design. In 1972, we made a similar modification to the HU hangers with a feature we call a jump seat. In the first HU designs, you’ll notice the “B” dimension of the hanger seat extends all the way up the side flanges. We only need that full “B” dimension for joist bearing at the seat, so we can remove that material some distance above the seat. By careful layout, we relocate that excess material from the “B” flange into the “A” flange, or face flanges. This reduced material use by about 40%.

What’s better than an HU? Well, an HHU, of course! The HHU hangers were identical to HU hangers, but used N20A nails instead of 16d nails to achieve higher allowable loads. In 1995, we modified the HU hangers to have minimum and maximum nailing and we discontinued the HHU. The minimum nailing requires only the round nail holes be filled, whereas maximum nailing requires both the round and triangle holes to be filled.