Hangbo Alloy Group
Shanghai · Est. 2012
Hot rolled, cold drawn and precision ground square, flat and rectangular nickel alloy bar for machined components, fixtures and structural hardware.
Square and flat bar is the economical starting form whenever a finished part is prismatic rather than cylindrical. Machining a bracket, a valve body blank, a furnace rail or a wear plate from flat stock removes far less metal than starting from round bar or plate, and the parallel faces give a datum that speeds up set-up on the machine. In nickel alloys the demand comes from furnace and heat-treat fixtures, chemical plant internals, pump and valve components, marine hardware, electrical resistance elements and weld-in structural details.
Hangbo supplies square bar from 8 mm to 150 mm across, and flat and rectangular bar from 10 mm to 200 mm wide in thicknesses from 3 mm to 60 mm. Lengths are 2–6 m random or cut to size, and we can slit plate to width where a non-standard flat section is needed. Finishes are hot rolled and descaled, cold drawn, precision ground, or ground on all four faces for gauge-critical work.
Because flat sections have a high surface-to-volume ratio, surface condition after hot working matters more than it does on round bar. All material is descaled by shot blasting and pickling, and edge conditioning is performed so that laps and seams do not carry into the finished component.
Hot rolled square and flat bar. Rolled from billet on a bar mill, then descaled. This is the standard route for larger sections and for the grades that crack if cold worked too aggressively.
Cold drawn square and flat bar. Drawn or drawn-and-shaped to close tolerance with sharp corners, tight width and thickness control and a clean bright surface. Width and thickness are normally held to h9–h11.
Precision ground flat bar. Ground on all faces to h8 or better with flatness and parallelism held for sealing faces, slideways and gauge applications. Surface finish of Ra 0.4–0.8 µm is routine.
Governing specifications. ASTM B166 for nickel-chromium-iron alloys, ASTM B160 for wrought nickel, ASTM B446 for Ni-Cr-Mo-Nb alloy (Inconel 625), ASTM B574 for the low-carbon Ni-Cr-Mo alloys, ASTM B164 for Monel, ASTM B425 for Incoloy 825, ASTM B473 for Alloy 20 and ASTM B335 for the Ni-Mo family. ASME SB- equivalents are applied where the part is pressure-retaining or covered by a code stamp.
Tolerances and lengths. Square bar to h9, h10 or h11; flat bar width to h9–h11 with thickness to ±0.05 mm on ground product. Straightness is normally 1 mm per metre, and bar is supplied with sawn or sheared ends, deburred and, where needed, stamped with the heat number at both ends.
Square and flat bar is produced across the alloy families our customers specify most:
Manufacturing route. Heat is melted by VIM, with ESR or VAR remelting for the grades destined for critical rotating or load-bearing service. Billet is hot forged or rolled to feedstock, then either hot rolled direct to finished section or cold drawn through shaped dies. Intermediate and final annealing is performed under controlled atmosphere or in batch furnaces with recorded charts, followed by descaling, straightening and, for ground product, precision surface grinding. Where the component will run hot under load for extended periods, the selection logic differs from room-temperature design; our article on creep and stress rupture in nickel superalloys covers the considerations. Cut plate blanks are also available from our nickel alloy plate and sheet range when the section exceeds bar mill capability.
Hangbo Alloy Group operates to ISO 9001:2015, with GJB 9001C for defence supply and GOST R for the Russian and EAEU market. Square and flat bar is shipped with EN 10204 type 3.1 documentation covering melt analysis, product analysis, tensile and hardness results, grain size and heat treatment records; type 3.2 certification and witness testing are arranged through BV, SGS, TUV, DNV or Lloyd's Register.
Ultrasonic testing to ASTM A388 is performed on the larger sections, surface inspection covers laps, seams and rolled-in scale, and dimensional reports list width, thickness, squareness, straightness and corner condition. Bundles are strapped, end-capped and wrapped, with heat numbers visible on every bar or tag so identification is not lost in transit.
Square bar runs from 8 mm to 150 mm across and flat and rectangular bar from 10 mm to 200 mm wide in thicknesses of 3 mm to 60 mm. Sections outside that range are normally cut from plate, which we can also supply.
Choose hot rolled and descaled for large sections, weldments and furnace fixtures where tolerance is secondary. Choose cold drawn or precision ground where the part runs on a machine without further machining of the faces, or where a sealing face, slideway or gauge surface is involved.
Where the project quantity justifies a dedicated melt we can plan production so that round, hex and flat stock share the same heat number, which simplifies your material certification and traceability. Tell us the full bill of material at enquiry stage and we will confirm feasibility.
Send us your grade, diameter, length, quantity, and any special requirements. Our team responds within 10 minutes during business hours.