Copper or Brass? Choose the Material Around the Part’s Function

Start with the part's job

These are reading routes, not automatic material selections. A part that conducts and flexes must meet both needs in the same supplied condition. [1][2]

Read the forming information with its conditions

A mill's bend table, a general application list and a patent design have different meanings. Bend data apply to the stated stock condition and test; a product listing identifies a candidate supply form; historical uses or design examples need confirmation for a current part. None is a ranking of alloy quality.

For all grades below, confirm the exact alloy, temper, product form, thickness and rolling direction before approving a process. Blanking, bending and deep drawing are separate operations. Each row focuses on the material's distinguishing information or a particular issue to check, while the later sections collect the shared drawing and validation requirements.

Copper grades: current and heat paths

A grade with greater bulk conductivity is not automatically the best spring contact. The current path includes joints and mating surfaces, and contact force can matter as much as base-metal conductivity for the interface. [1]

Brass: formed parts, contacts and appearance

Brass color does not identify either its alloy or a surface coating. If the part sees moisture, cleaning agents or sustained stress, include that exposure in the material and finish review. The suitable alloy and process must be selected for the assembly. [1]

Copper-iron and high-performance connector strip

These alloys are candidates when a terminal must balance conductivity with strength or retained contact force. The trade-off is grade- and temper-specific; a harder or stronger strip may leave less forming margin. [1][2]

Phosphor bronze: spring contacts and formed features

The mill literature lists phosphor bronze strip for spring and press-fit contacts. These applications need enough forming margin during manufacture and enough retained force in service. Check the actual part's deflection and working temperature as well as conductivity. [1]

Copper-nickel, copper-nickel-tin and nickel silver

Nickel silver is a family name for copper-nickel-zinc alloys; it does not by itself specify silver plating. [4]

Selected aluminum and silicon bronzes

Copper beryllium: separate the material choice from the process route

NGK Berylco lists both C17200 and C17510 as copper-beryllium strip, but the grades offer different strength and conductivity combinations. C17200 is a candidate where high strength is needed; C17510 is a candidate when conductivity and mechanical strength must be balanced. Check the exact product and temper against the contact requirement. [5]

Some strip is supplied for forming followed by a strengthening treatment; other products have a different supply and processing route. Obtain the supplier's condition-specific instructions instead of assuming the same treatment for every grade. [5]

Beryllium-containing dust, fumes or mist can create occupational exposure. For operations such as grinding, deburring, heating or cleaning equipment and scrap, assess the actual work, consult the material safety data sheet and apply the relevant workplace controls. [6]

C41100 and C61900: what the cold-forming evidence establishes

C41100. The flexible-hose strip specification is an example of annealed material for a defined product; it does not establish which condition is suitable for a different stamped part. Confirm the actual product form, material specification, temper, thickness and grain direction with the supplier. Obtain grade- and condition-specific information for blanking and bending, then evaluate the proposed blanked edge and the final geometry on representative stock. Grade- and stock-specific blanking clearance and bend limits must be established before release. [27]

C61900. A published vendor table gives typical room-temperature properties for flat-product examples in O61 annealed and H02 half-hard conditions at a listed 0.04 in section size. These are property examples, not proof that either temper is commercially available as the required strip or will blank or bend successfully for a particular part. The same vendor lists several forming operations without stating whether each is cold or hot. ASM describes the alloy's general capacity for cold work as fair. Confirm stock availability and the supplied material condition before drawing conclusions about an operation. [31][32][33]

Do not treat the sheet-and-strip title of ASTM B169/B169M as proof that it covers C61900: the cited 2015 edition lists C61300 and C61400. Select the governing specification for the actual product and check its current applicable edition. [34]

For both grades, a drawing review should identify strip thickness and tolerance, temper and specification, rolling direction relative to the bend axis, bend angle and inside radius, critical edges and burr limits. Agree sample quantity and acceptance criteria with the material and tooling suppliers. Assess blanking by examining the actual cut edge and die condition; assess bends for cracking and springback with representative material and the specified geometry. Set any trial die clearance or bend radius with the toolmaker and material supplier, then validate it—the available sources do not establish reproducible alloy-specific clearance or minimum R/t for the stock being ordered.

Where appropriate, a copper-alloy bend test can help establish agreed stock-specific evidence. China’s YS/T 1773-2025 describes a bend-test method for copper and copper-alloy strip and foil in its stated 0.04–1.0 mm thickness scope; that scope is not a minimum bend radius, a stamping clearance, or automatic approval of either alloy. The C61900 property example above lists a nominal 0.04 in (1.016 mm) section size but does not establish that this dimension is strip thickness; its eligibility for that thickness scope remains unconfirmed. Confirm the actual test method and acceptance criteria for the project. [35]

Check the material certificate against the order

A material certificate should identify the ordered alloy and product specification, temper, sheet or strip form, thickness and tolerances, and the relevant batch. Record a mill trade name separately from a UNS or national designation, and agree who approves any proposed substitution. A certificate for another product form is not evidence for the ordered strip.

A standards-project document also lists TCr0.3-0.15-0.03, TCr1-0.15, HSn88-0.7, QSn2-0.2, QSn2.0-0.1-0.03 and BSi2-0.5 as material leads. The document is not evidence that every grade is available in the ordered strip form or fits a given stamping operation. Confirm each designation against the governing standard, supplier's current data sheet, alloy properties and applicable use. Do not assume it is interchangeable with a similarly named UNS grade. [7]

Choose the strip around the finished part

For a current-carrying spring contact, mark the current path and the mating zone separately. Define the current duty, required deflection and force, working temperature and permitted finish. Compare candidate grades and tempers, then check the finished assembly. A conductive base metal alone cannot establish contact resistance or temperature rise. [1]

Use the following as an RFQ note alongside a drawing, sketch or photograph. Write “to be confirmed” for open material or process decisions.

If the grade is undecided, explain what the part conducts, touches or moves and which dimensions or functions cannot change. Agree the material and required validation before production.