Ball Bearing 4" x 4" Square with 5/8" Radius Corner Stainless Steel - 304 Grade. Highly Rust Resistant making it great for Coastal Areas. Gauge: 2.5MM, (.097" ) For Door Thickness: 1 5/8" to 1 3/4" thick doors Includes matching screws. Non-Removable Pin - Pin is riveted on and cannot be removed. These hinges are perfect for out-swing doors where security is an issue. Sold in sets of 3 - 3 Complete Hinges