Copper Alloys


COLDUR-A® (C65500) is a high copper alloy that is renowned for its combination of strength, corrosion resistance and formability and for its attractive colour. Known as a high silicon bronze, COLDUR-A® (C65500) is renowned as being one of the easiest of all copper alloys to fabricate – by a wide range of techniques – and is readily formable by both hot and cold methods. It offers excellent forming characteristics combined with an attractive rich, reddish old gold colouration that makes the alloy highly desirable for many architectural and decorative applications.

Its strength and corrosion resistance ensure it is suitable for many other applications from architectural metalwork and marine hardware to electrical components and chemical engineering. Small additions of silicon and manganese to the copper enhance the overall corrosion resistance and mechanical properties of the silicon bronze alloy without any detrimental effect on the workability of the material.

The alloy is used extensively in architectural applications and is a favourite medium for many sculptors. In addition, COLDUR-A® (C65500) silicon bronze finds numerous uses in chemical and process plant and water storage systems as well as for fasteners and many other general engineering applications.

Related Specifications of COLDUR-A® (C65500)

  • CS101
  • C65500
  • C65600
  • CW116C
  • ASTM B98
  • ASTM B249
  • 2.1525
  • 2.1522
  • CuSi3Mn1
  • CuSi2Mn (DE)
  • CuSi3Mn (DE)

Nominal Composition of COLDUR-A® (C65500)

Cu rem, Si 3.0%, Mn 1.0%

Mechanical Properties of COLDUR-A® (C65500)

Ultimate Tensile Strength (N/mm²) Proof Stress (N/mm²) Elongation (%) Hardness (HB)
485 260 20

Key Features of COLDUR-A® (C65500)

  • Excellent hot and cold formability
  • High strength properties
  • Attractive reddish old gold colouration
  • Excellent general corrosion resistance
  • Low magnetic permeability

Applications of COLDUR-A® (C65500)

Architectural & decorative | Furniture, fire place surrounds, nameplates, sculptures, signs, bolts, cladding, door and window frames; hinge pins, latches, masonry fixings, slate and tile nails; panels, spring brackets, screws, step irons, tension bolts and wall ties

Electrical | current-carrying electrical components such as slip rings, squirrel cages, springs, rotary switch contacts, contact blades, short-circuit rings, heavy-duty switchgear, bearing plates, bolts, busbar clamps, bushes, clutch discs, cotter pins, electrical conduit, fasteners, locking washers, piston rings, thrust washers and u-bolts

Automotive | valve guides, bushes and valve seats

Chemical processing | Autoclaves, chemical apparatus, drains, explosives plant, fans and ducts for corrosive vapours, fasteners, heat exchanger tube plates, filters, pickling and recovery plant, pressure vessels, pump rods and shafts, screen plates, stirrers, valve stems, vats and washers.

Offshore & marine |  Fasteners, propeller shafts, hull and deck fittings, fuel and water tanks, non-magnetic instrumentation, subsea electromechanical equipment and other hardware

Case Studies

COLDUR-A® (C65500): mirror frames and tables
COLDUR-A® (C65500): prizewinning staircase handrail
COLDUR-A® (C65500): chandelier candle holders
COLDUR-A® (C65500): keel bolts
COLDUR-A® (C65500): S
hakespeare’s New Place

Columbia Metals – a leading supplier of COLDUR-A® (C65500)

With decades of experience and a huge range of stock, Columbia Metals is an industry leader in the supply of COLDUR-A® (C65500) and other high quality specialist engineering alloys.

To buy or learn more about COLDUR-A® (C65500) contact us now, or fill in the enquiry form on the right hand side and we will be in touch shortly.

  Related Specifications Mechanical Properties
Alloy Name BS UNS BS EN Others Ultimate Tensile Strength N/mm² Minimum Yield Strength N/mm² Elongation % Hardness HB  
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