David Bolton Knockdown Frame Assembly Sequence: The Order of Operations That Keeps a Steel Frame Plumb From Corner to Anchor What This Guide Covers and Who It Helps A knocked-down (KD) steel door frame ships in three separate pieces -- two jambs and a head -- and must be assembled on site before it can be set in the wall. G... KD frame installation fire-rated openings frame assembly hollow metal frames steel door frames Jun 28, 2026
David Bolton Mixing Square and Radius Corner Spring Hinges on the Same Door: When the Frame Prep Decides the Hinge Profile The Problem That Shows Up at the Jobsite, Not on the Schedule This article is for contractors, facility managers, and architects who have ordered spring hinges and discovered — after the door was prep... commercial door hardware fire-rated openings hinge corner profile hollow metal frames spring hinges May 18, 2026