Fire performance isn't simply the core; bracket alloys, screw grades, and surface systems all affect scores

https://www.scribd.com/document/1042029003/The-Heritage-of-Hand-Fabricated-Metal-Customized-Leader-Boxes-Designed-to-Endure-a-Century-198695

Fire performance isn't simply the core; brace alloys, screw grades, and finish systems all impact ratings, so settings up are examined with each other for real-world compliance.