Here are the specifications for this door. We are using Steel Craft L-18 door and 16 gauge frame. Doors: L-Series (laminated door construction) L20(.8mm) - L18(1mm) - L16(1.3mm) - L14(1.7mm) Steelcraft L-Series doors are designed to meet architectural requirements for full flush door constructions. The L-Series door combines the strength and dimensional stability of steel with the structural integrity of the honeycomb core. The continuous bonding of core to metal provides an attractive, absolutely flat door, free of face welding marks. Tests have proven the L-Series door's high resistance to impact damage, low thermal conductivity and have validated the high STC ratings of this door.  Features: Standard:  Edges: Beveled (1/8" in 2")  Edge Construction: Visible edge seams  Core: Honeycomb  Steel Types Cold Rolled Steel  Internal Reinforcements Same steel type as door .  Specifications  Door thickness: 1-3/4" (45mm)  Door heights: 7'0"  Door width: 3'0"  Steel: 18,gauge cold rolled Must have 90 minute fire rating and also have demand for a 3 hour fire rating.