In heist movies, nothing says "you're not getting in" quite like a massive steel vault door swinging shut. The bolts slide into place, and whatever is on the other side is sealed off from the world. We wanted to see how much of that "technology" is the steel itself.
For the latest installment of Riverbank's Novelty Testing Series, we tested a 48" x 96" sheet of nominal 1/4" ASTM A36 structural steel, all 318 pounds of it, to determine its sound transmission loss and single-number sound insulation ratings using ASTM E90 and ASTM E413 procedures.
The steel posted a Sound Transmission Class (STC) of 36 and an Outdoor-Indoor Transmission Class (OITC) of 36. That's a solid showing for a single bare sheet, but it's not the dead silence the movies promise. The data also shows a clear dip around 2,000 Hz, where the sheet's own stiffness lets more sound slip through. If you want a steel door that truly keeps a room quiet, it takes more engineering than mass alone. Check out our latest novelty test report to see the full transmission loss data across the frequency range we tested. Download the report at the link below to add to your library and share with your friends and colleagues.
