In February of 2018, Portland Bolt shipped 24’ and 10’ long galvanized threaded rods for a highly specialized project for the Air Force radar station. This project replaced high strength anchor bolts and down guy anchor bolts for a radar tower on the remote Barter Island in Alaska. These threaded rods, heavy hex nuts, and couplers had to be 100% domestic and fully hot-dip galvanized, but most importantly all hardware had to be able to handle the extreme cold temperatures of Alaska. Ten of the twelve months of the year Barter Island has an average low monthly temperature that is well below freezing, often reaching lows of -20 F or lower. Due to this extreme cold, all of the anchor bolts that were to be embedded and the connecting hardware that would connect to the guy wire would need to be Charpy Impact tested for low-temperature performance. During a Charpy Impact test, a sample coupon is impacted by a pendulum to gauge the performance of steel at varying temperatures. Typically this test is used to see how brittle the test material becomes at lower temperatures to ensure it remains ductile, keeping its full strength, and performing as intended.
Portland Bolt supplied custom ASTM A320 Grade L7 threaded rods and all thread rod, as well as custom ASTM A194 Grade 7 heavy hex nuts and heavy hex coupling nuts. Portland Bolt also supplied large round A572 Grade 50 plates that were custom made and embedded at the bottom of the anchor rods for pull-out resistance. All materials were high strength, hot-dip galvanized, and Charpy Impact tested for low-temperature performance.