The National Mfg. Co. of Sterling, Illinois made this pair of barn door rollers. The patent date on this pair is April 24, 1906. The title or brand of this particular item was “Big 4.” However, the wheels (rollers) only measure 3 1/2 inches.
Each U frame measures 7 inches in length and 5 1/2 inches wide. On the back of the U are two 3/4 inch studs to help hold the track in place. The box that hold the wheel measures 5 inches vertically and 3 1/2 inches horizontally.
We have only brushed the dirt off of this pair. They are complete, and the rollers are smooth running. To find original barn hardware like these is a challenge. Total weight of the pair is 6 pounds, 6 ounces. br>