The Chicago Expansion Bolt performs so well that it has been used to secure the seating in most theatres and stadiums in the United States since 1916.Our products are very easy to install and have stood the test of time from Auditoriums to Stadiums all across North America. Installers have chosen our expansion devices for their convenience and dependability. Our expansion bolts, hook bolts, and No.1 tumble toggles are stronger than comparable products. Their unique designs often save time during installation. Try our bolts for their convenience and dependability during your next installation.