Steel Door Frames
2003 Edition

IS 4351 (2003) permits manufacturing steel door frames using mild steel sheets (cold rolled) of 1.25 mm or 1.60 mm thickness as per IS 513, galvanized steel sheets of 1.00 mm, 1.25 mm, or 1.60 mm thickness with zinc coating 120 g/m² both sides complying with IS 277, and stainless steel sheets of 1.00 mm thickness of grades X07Cr17 (430) or X04Cr19Ni9 (304 S1) as per IS 6911. Surface treatments like mechanical or chemical cleaning followed by phosphating and painting or powder coating are recommended to enhance durability and corrosion resistance.

IS 4351 specifies five standard frame profiles for steel door frames suitable for doors opening either inward or outward. These are Profile A (90 mm width x 60 mm depth, single rebate), Profile B (105 x 60 mm, single rebate), Profile C (125 x 60 mm, single rebate), Profile D (125 x 60 mm, double rebate), and Profile E (165 x 60 mm, double rebate). Frames include hinge jamb, lock jamb, head, and base ties, and are fabricated by welding or mechanical fixing. The overall frame size accommodates a 5 mm clearance on all sides for fitting into modular openings.

Per IS 4351 Clause 10.2.4, hinges are to be fixed by screwing onto a mild steel plate (120 mm x 30 mm x 6 mm) that is welded inside the door frame. The plate is internally threaded to accept M5 x 20 countersunk machine screws (as per IS 1365), ensuring a secure and durable attachment. Medium weight hinges of 100 mm size conforming to IS 1341 or IS 12817 standards are typically used, with alternative fixing methods specified by the purchaser if required.

IS 4351 recommends thorough cleaning of mild steel frames by mechanical (sand or shot blasting) or chemical (pickling and phosphating as per IS 1477 Part 1) methods, followed by application of two coats of red oxide zinc chrome primer (IS 2074) through brushing, spraying, or dipping (IS 1477 Part 2). Galvanized steel frames require chemical pre-treatment and phosphating without pickling before painting or powder coating. Stainless steel frames are pickled and passivated chemically, generally not requiring paint but optionally finished with spray painting or powder coating. These treatments ensure corrosion resistance and aesthetic durability.

When placing an order for steel door frames under IS 4351, the purchaser should provide the overall frame dimensions (height and width measured to the outside), profile designation (A, B, C, D, or E), material type and sheet thickness (mild steel, galvanized steel, or stainless steel with respective thicknesses), preferred finish (painting or powder coating), hardware details including hinge types and fixing methods, and door handing plus closing direction as per IS 4043. Providing this information ensures the correct production, fitting, and standard compliance of the door frames.