Square cross-section bar to ASTM A479 / A276 for key stock, square-head fitting blanks, and structural framing
Square bar fills the gap between flat bar and round bar where the part has a square or rectangular finished profile and the manufacturer wants the as-supplied geometry close to the finished part. Common downstream uses are pump shaft key stock per ANSI B17.1, square-head plug and pipe fitting blanks, framing for instrumentation enclosures in chloride service, and machining stock for square flanged components. Ferralium 255 (UNS S32550, EN 1.4507) square bar covers 6 mm to 150 mm cross-section per ASTM A479 / A276 and EN 10088-3, supplied solution-annealed at 1080 °C with water quench. Per-heat EN 10204 type 3.2 MTC. RFQ: info@torqbolt.com / WhatsApp +91-22-66157017.
| Side dimension | Tolerance class | Length | Use case |
|---|---|---|---|
| 6 mm to 14 mm | ISO h11 (cold-drawn) | up to 6 m | Pump shaft key stock per ANSI B17.1 |
| 14 mm to 50 mm | ISO h11 (cold-drawn or peeled) | up to 6 m | Square plug and fitting blank feedstock |
| 50 mm to 100 mm | ISO h12 (hot-rolled / peeled) | up to 6 m | Structural framing, square flange blank |
| 100 mm to 150 mm | ISO h13 (hot-rolled) | up to 4 m | Heavy-section structural and machining feedstock |
Square bar in the smaller AF range (6 mm to 25 mm) is the standard pump shaft key feedstock per ANSI B17.1 / DIN 6885. The key cross-section is selected to match the pump shaft diameter (typically 1/4 of the shaft diameter), and the key length is selected to deliver the required torque transmission based on bearing stress on the key flank. Super duplex key stock is specified where the keyway environment sees seawater or sour fluid that would corrode standard 304 / 316 keys, particularly in submersible pumps, downhole rotating equipment, and FPSO process pump skids.
