spore: profile
id: yellow-brass-cw508l
spore_version: 0.2
family: copper-alloys
name: Brass CW508L (CuZn37)
abbreviation: CW508L
role: cold-working alpha brass
category: metals
type: copper-alloys
summary: Brass CW508L (CuZn37 under EN 573-3, also called CZ108 by Righton and Blackburns) is an alpha brass with copper at 62.00 to 64.00 % and zinc as the balance, per Righton's EN 1652 composition table. Its density is 8.44 g/cm3 and its thermal conductivity is 120 W/m*K at 20°C, per the BIKAR physical properties table. Righton gives a sheet tensile strength of 300-550 MPa and a tube minimum of 440 MPa, with no temper stated. Both suppliers describe good resistance to water and salt solutions, but Wikipedia reports that NSF International requires plumbing brasses with more than 15% zinc to be dezincification-resistant, and that brass can season crack in ammonia after cold work.
best_for: Formed sheet, tube and drawn parts that need good cold working and bending, plus brazed or soldered assemblies (Righton and BIKAR)
weakest_at: Dezincification in chloride or soft water and season cracking in ammonia when cold work leaves stress; the sources give no test result for CW508L in either case
identity:
  formula: 'CuZn37 (EN 573-3, ISO CuZn37): copper 62.00 to 64.00 %, lead 0.00 to 0.10 %, iron 0.00 to 0.10 %, nickel 0.00 to 0.30 %, tin 0.00 to 0.10 %, aluminium 0.00 to 0.05 %, others 0.00 to 0.20 % total, zinc balance (Righton EN 1652 table); BIKAR prints Cu 62 to 64, Fe 0.1, Ni 0.3, Pb 0.1, Sn 0.1, Al 0.05, Other 0.1 and Zn as the rest'
  source: righton-cw508l
  where: Chemical Composition table (EN 1652 CW508L Brass), Righton page 1; Chemical specifications table on the BIKAR page
  designations:
    - system: EN name
      code: CW508L
      source: righton-cw508l
      where: 'Specifications table, EN row: CW508L'
    - system: EN
      code: '2.0321'
      source: bikar-cw508l
      where: 'Material no row: CW508L (2.0321)'
    - system: EN name
      code: CuZn37
      source: bikar-cw508l
      where: 'Material chemically EN 573-3 row: CuZn37'
    - system: ISO
      code: CuZn37
      source: righton-cw508l
      where: 'Alloy designations box: ISO CuZn37'
    - system: BS
      code: CZ108
      source: righton-cw508l
      where: 'Title block CW508L (CZ108) and Specifications table, Commercial row: CZ108'
tags:
  environments: []
  stresses: []
  applications:
    - thermal-control
    - mechanisms
    - electronics-and-chips
properties:
  - benchmark: density
    label: Density, brass CW508L (BIKAR)
    value: 8.44
    unit: g/cm3
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: not stated
      unit_in_source: 8.44 g/cm³
    method: Value printed in the physical properties table of a stockist product page
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Density row
  - benchmark: elastic_modulus
    label: Modulus of elasticity at 20 °C, brass CW508L (BIKAR)
    value: 110
    unit: GPa
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 20 °C
      unit_in_source: 110 GPa
    method: Value printed in the physical properties table of a stockist product page
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Modulus of elasticity at 20°C row
  - benchmark: electrical_resistivity
    label: Specific electrical resistance at 20 °C, brass CW508L (BIKAR)
    value: 0.066
    unit: Ω·mm²/m
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 20 °C
      unit_in_source: 0.066 Ω*mm²/m
    method: Value printed in the physical properties table of a stockist product page; the unit is kept as printed and converted on import
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Specific electrical resistance at 20°C row
  - benchmark: electrical_resistivity
    label: Specific electrical resistance at 200 °C, brass CW508L (BIKAR)
    value: 0.083
    unit: Ω·mm²/m
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 200 °C
      unit_in_source: 0.083 Ω*mm²/m
    method: Value printed in the physical properties table of a stockist product page; the unit is kept as printed and converted on import
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Specific electrical resistance at 200°C row
  - benchmark: electrical_conductivity
    label: Specific electrical conductivity at 20 °C, brass CW508L (BIKAR)
    value: 15
    unit: m/(Ω·mm²)
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 20 °C
      unit_in_source: 15 m/Ω*mm²
    method: Value printed in the physical properties table of a stockist product page; not a canonical benchmark name, see gaps
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Specific electrical conductivity at 20°C row
  - benchmark: electrical_conductivity
    label: Specific electrical conductivity at 200 °C, brass CW508L (BIKAR)
    value: 12
    unit: m/(Ω·mm²)
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 200 °C
      unit_in_source: 12 m/Ω*mm²
    method: Value printed in the physical properties table of a stockist product page; not a canonical benchmark name, see gaps
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Specific electrical conductivity at 200°C row
  - benchmark: specific_heat
    label: Specific heat at 20 °C, brass CW508L (BIKAR)
    value: 0.377
    unit: J/(kg·K)
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 20 °C
      unit_in_source: 0.377 J/(kg·K)
    method: Value printed in the physical properties table of a stockist product page
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Specific heat at 20°C row
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 20 °C, brass CW508L (BIKAR)
    value: 120
    unit: W/m*K
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 20 °C
      unit_in_source: 120 W/m*K
    method: Value printed in the physical properties table of a stockist product page
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Thermal conductivity at 20°C row
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 200 °C, brass CW508L (BIKAR)
    value: 142
    unit: W/m*K
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: 200 °C
      unit_in_source: 142 W/m*K
    method: Value printed in the physical properties table of a stockist product page
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Thermal conductivity at 200°C row
  - benchmark: thermal_conductivity
    label: Thermal conductivity at -200 °C, brass CW508L (BIKAR)
    value: 50
    unit: W/m*K
    scope: material
    conditions:
      grade: CW508L (EN 573-3 CuZn37)
      temper: not stated
      temperature: '-200 °C'
      unit_in_source: 50 W/m*K
    method: Value printed in the physical properties table of a stockist product page
    status: ground
    source: bikar-cw508l
    where: Physical properties table, Thermal conductivity at -200°C row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, sheet 0.2 mm to 5.00 mm (range)
    value: 300
    value_high: 550
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: CW508L (EN 1652)
      temper: not stated
      product_form: sheet 0.2 mm to 5.00 mm
      unit_in_source: 300-550 MPa
    method: Range printed in the Mechanical Properties table of a stockist datasheet, sheet column
    status: ground
    source: righton-cw508l
    where: Mechanical Properties table (EN 1652), Tensile Strength row, sheet 0.2 mm to 5.00 mm
  - benchmark: yield_strength
    label: Proof stress as printed, sheet 0.2 mm to 5.00 mm (range)
    value: 110
    value_high: 500
    bound: range
    unit: MPa
    scope: material
    conditions:
      grade: CW508L (EN 1652)
      temper: not stated
      product_form: sheet 0.2 mm to 5.00 mm
      printed_name: Proof Stress
      offset: not stated
    method: Range printed as Proof Stress in the sheet table of a stockist datasheet; the datasheet does not state the proof offset
    status: ground
    source: righton-cw508l
    where: Mechanical Properties table (EN 1652), Proof Stress row, sheet 0.2 mm to 5.00 mm
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, tube up to 5.00 mm wall (minimum)
    value: 440
    bound: lower
    unit: MPa
    scope: material
    conditions:
      grade: CW508L (EN 12449)
      temper: not stated
      product_form: tube up to 5.00 mm wall thickness
      measure: minimum
      unit_in_source: 440 Min Mpa
    method: Minimum value printed in the tube table of a stockist datasheet
    status: ground
    source: righton-cw508l
    where: Tube up to 5.00mm Wall Thickness table (EN 12449), Tensile Strength row
  - benchmark: yield_strength
    label: Proof stress as printed, tube up to 5.00 mm wall (minimum)
    value: 320
    bound: lower
    unit: MPa
    scope: material
    conditions:
      grade: CW508L (EN 12449)
      temper: not stated
      product_form: tube up to 5.00 mm wall thickness
      measure: minimum
      printed_name: Proof Stress
      offset: not stated
    method: Minimum value printed in the tube table of a stockist datasheet; the datasheet does not state the proof offset
    status: ground
    source: righton-cw508l
    where: Tube up to 5.00mm Wall Thickness table (EN 12449), Proof Stress row
  - benchmark: hardness_vickers
    label: Hardness Vickers, sheet (range)
    value: 55
    value_high: 180
    bound: range
    unit: HV
    scope: material
    conditions:
      grade: CW508L (EN 1652)
      temper: not stated
      product_form: sheet 0.2 mm to 5.00 mm
    method: Range printed in the Mechanical Properties table of a stockist datasheet; not a canonical benchmark name, see gaps
    status: ground
    source: righton-cw508l
    where: Mechanical Properties table (EN 1652), Hardness Vickers row, sheet
  - benchmark: hardness_vickers
    label: Hardness Vickers, tube up to 5.00 mm wall (minimum)
    value: 115
    bound: lower
    unit: HV
    scope: material
    conditions:
      grade: CW508L (EN 12449)
      temper: not stated
      product_form: tube up to 5.00 mm wall thickness
      measure: minimum
    method: Minimum value printed in the tube table of a stockist datasheet; not a canonical benchmark name, see gaps
    status: ground
    source: righton-cw508l
    where: Tube up to 5.00mm Wall Thickness table (EN 12449), Hardness Vickers row
  - benchmark: hardness_brinell
    label: Hardness Brinell, tube up to 5.00 mm wall (minimum)
    value: 110
    bound: lower
    unit: HB
    scope: material
    conditions:
      grade: CW508L (EN 12449)
      temper: not stated
      product_form: tube up to 5.00 mm wall thickness
      measure: minimum
    method: Minimum value printed in the tube table of a stockist datasheet; not a canonical benchmark name, see gaps
    status: ground
    source: righton-cw508l
    where: Tube up to 5.00mm Wall Thickness table (EN 12449), Hardness Brinell row
  - benchmark: elongation
    label: Elongation A, tube up to 5.00 mm wall (minimum)
    value: 10
    bound: lower
    unit: '%'
    scope: material
    conditions:
      grade: CW508L (EN 12449)
      temper: not stated
      product_form: tube up to 5.00 mm wall thickness
      measure: minimum
      gauge: A, gauge length not stated
    method: Minimum value printed in the tube table of a stockist datasheet
    status: ground
    source: righton-cw508l
    where: Tube up to 5.00mm Wall Thickness table (EN 12449), Elongation A row
corrosion:
  - environment: Water, water vapour, various salt solutions and many organic liquids
    headline: BIKAR says the alloy has good resistance to water, water vapour, various salt solutions and many organic liquids.
    effect: 'BIKAR''s features list reads: good resistance to water, water vapour, various salt solutions, many organic liquids. Righton also gives good corrosion resistance as a characteristic. Neither source gives a corrosion rate, test time or threshold.'
    rating: low
    conditions:
      basis: qualitative supplier statement; no rate, test or time printed
    source: bikar-cw508l
    where: Features of this material box
  - environment: Water with chlorides, high temperature or soft water (dezincification)
    headline: Wikipedia says dezincification-resistant brasses are used where the corrosion risk is large, including high water temperatures, chlorides and soft water.
    effect: Wikipedia says DZR brasses are used where the risk of corrosion is large, and that applications with high water temperatures, chlorides present or deviating water qualities (soft water) play a role. It adds that NSF International requires brasses with more than 15% zinc, used in piping and plumbing fittings, to be dezincification-resistant. CW508L has zinc as its balance, and no dezincification test for this grade was read.
    rating: moderate
    conditions:
      basis: qualitative statement from Wikipedia on brass in general; the rating is an assistant judgement from the zinc statement, not a test on CW508L
      zinc_threshold_cited: more than 15% zinc
    source: wiki-brass
    where: Corrosion-resistant brass for harsh environments section, DZR paragraph
  - environment: Ammonia or amine atmospheres with tensile stress (season cracking)
    headline: Cold-worked brass can crack in ammonia or amines when tensile stress is left in the part, and stress relief removes that stress.
    effect: Hendrix says that for brasses the environment involved is usually one containing ammonia or closely related substances such as amines. Cold working such as pressing, spinning, drawing and bending leaves internal stresses that can lead to stress corrosion cracking unless they are removed by stress relief heat treatment. Cracking is usually localised and may be accompanied by black staining where ammonia was involved. Hendrix says a markedly intergranular crack pattern is usual in simple alpha brasses, which Righton describes CW508L as.
    rating: moderate
    conditions:
      basis: qualitative description for brasses in general; no threshold stress or time to crack for CW508L is printed in the sources
    source: hgh-scc
    where: Brasses section, Environment, Cold working and Metallographic examination paragraphs
risks:
  hazards:
    - text: 'Lead: Righton and BIKAR both list a lead maximum of 0.10 %. ATSDR says lead can cause health problems in almost every organ and system in the body. No GHS classification or exposure limit for this alloy was read.'
      ghs: []
      source: atsdr-lead
      where: 'ToxFAQs: How can I be exposed to lead; How can lead affect my health'
    - text: 'Zinc fume: ATSDR says inhaling large amounts of zinc as dusts or fumes can cause metal fume fever, a short-term illness. Its ToxFAQ also lists welding and the manufacture of brass or other zinc-containing alloys among jobs with zinc exposure. No GHS code or exposure limit for CW508L was read.'
      ghs: []
      source: atsdr-zinc
      where: 'ToxFAQs: How can zinc affect my health? (metal fume fever paragraph); list of jobs with zinc exposure'
  failure_risks:
    - mode: Dezincification in water
      trigger: Water with chlorides, high water temperatures or soft water
      consequence: Wikipedia says the risk is handled with dezincification-resistant brass made with care to avoid long-term failures. No dezincification depth or rate for CW508L was read.
      severity: moderate
      source: wiki-brass
      where: Corrosion-resistant brass for harsh environments section, DZR paragraph
    - mode: Season cracking in ammonia or amines
      trigger: Tensile stress left by cold work (pressing, spinning, drawing, bending) or overtightened assembly, together with an ammonia or amine atmosphere
      consequence: Localised cracking, usually intergranular in simple alpha brasses, which may show black staining where ammonia was involved (Hendrix Group).
      severity: moderate
      source: hgh-scc
      where: Brasses section, Environment and Cold working paragraphs
  side_effects: []
  handling:
    - text: Stress-relieve parts after cold work such as pressing, spinning, drawing and bending. Hendrix says residual stresses can lead to stress corrosion cracking unless they are removed or substantially reduced by stress relief heat treatment.
      source: hgh-scc
      where: Cold working operations paragraph
    - text: Keep parts out of ammonia and amine atmospheres in service. Hendrix names these as the usual cracking environments for brass, and says to ventilate well after using latex cement.
      source: hgh-scc
      where: Environment and Sources of contamination paragraphs
    - text: Specify the product form and temper on the order. Righton gives different strength figures for sheet and for tube, and states no temper for either.
      source: righton-cw508l
      where: Mechanical Properties table and Tube table
  mitigations:
    - text: Choose a less susceptible brass where the service allows. Hendrix says low zinc rather than high zinc alloys, nickel silver rather than simple brass, and aluminium brass rather than admiralty improve stress corrosion resistance.
      source: hgh-scc
      where: Brasses section, final mitigation paragraph
    - text: Control manufacturing, assembly and operating conditions so that high stress and an unfavourable environment do not combine, since Hendrix says all brasses are susceptible to some degree.
      source: hgh-scc
      where: Brasses section, final mitigation paragraph
uses:
  - application: thermal-control
    device: Heat exchangers and radiator tanks
    example: Righton lists heat exchangers and radiator tanks among CW508L applications; BIKAR lists water boxes for car radiators. No source names a spacecraft thermal system; this application tag is our mapping.
    source: righton-cw508l
    where: Applications list, page 2 of the Righton datasheet; Areas of application on the BIKAR page
  - application: mechanisms
    device: Hinges, locks, pins, rivets, screws, springs, chains and fasteners
    example: Righton lists hinges, locks, pins, rivets, screws and springs, chains and fasteners as applications. BIKAR lists pneumatic cylinders.
    source: righton-cw508l
    where: Applications list, page 2 of the Righton datasheet; Areas of application on the BIKAR page
  - application: electronics-and-chips
    device: Switch components and contact parts
    example: Righton lists switch components and BIKAR lists contact parts as applications. This tag is our mapping; no source names a space or electronics system.
    source: righton-cw508l
    where: Applications list, page 2 of the Righton datasheet; Areas of application on the BIKAR page
supply:
  - subject: Copper (mine production 2025e), the main metal of CW508L (copper 62.00 to 64.00 % per Righton)
    abundance: 'USGS world mine production 2025e: 23,000 thousand t (world total, rounded)'
    producers:
      - country: Chile
        share_percent: 23
        year: 2025
      - country: Congo (Kinshasa)
        share_percent: 13.9
        year: 2025
      - country: Peru
        share_percent: 11.7
        year: 2025
      - country: China
        share_percent: 7.8
        year: 2025
      - country: Russia
        share_percent: 5.7
        year: 2025
    critical_lists:
      - list: U.S. Final 2025 List of Critical Minerals (copper added, per the USGS copper summary)
        listed: true
    recycling: 'USGS: brass and wire-rod mills accounted for approximately 80% of the total copper recovered from scrap.'
    substitutes: []
    source: usgs-mcs2026-copper
    where: World Mine and Refinery Production and Reserves table, Mine production 2025e column (world total 23,000 thousand t; shares calculated by Space Mushroom from the printed values 5,300, 3,200, 2,700, 1,800 and 1,300 thousand t); Critical minerals paragraph; Recycling paragraph
  - subject: Zinc (mine production 2025e), the balance of CW508L
    abundance: 'USGS world mine production 2025e: 13,000 thousand t (world total, rounded)'
    producers:
      - country: China
        share_percent: 31.5
        year: 2025
      - country: Peru
        share_percent: 11.5
        year: 2025
      - country: Australia
        share_percent: 8.5
        year: 2025
      - country: Mexico
        share_percent: 6
        year: 2025
    critical_lists: []
    recycling: 'USGS: refined zinc produced in the United States was recovered from secondary materials, including galvanizing residues and crude zinc oxide recovered from electric arc furnace dust.'
    substitutes:
      - 'USGS: many elements are substitutes for zinc in chemical, electronic and pigment uses. The summary does not name a substitute for zinc in brass.'
    source: usgs-mcs2026-zinc
    where: World Mine Production and Reserves table, 2025e column (world total 13,000 thousand t, rounded; shares calculated by Space Mushroom from the printed values 4,100, 1,500, 1,100 and 780 thousand t); Recycling paragraph; Substitutes paragraph
documents:
  - title: 'Righton and Blackburns: CW508L (CZ108) sheet and tube datasheet, updated 05 December 2024'
    type: datasheet
    url: https://www.rightonblackburns.co.uk/datasheets/view/Righton-Blackburns-Ltd_Copper-and-Copper-Alloys-CW508L-CZ108-Sheet_114.pdf
  - title: 'BIKAR: brass CW508L roundbar (drawn), chemical specifications and physical properties'
    type: datasheet
    url: https://my.bikar.com/en_US/products/208_303-208-303-2
  - title: 'USGS Mineral Commodity Summaries 2026: Copper'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Zinc'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf
    year: 2026
  - title: 'Wikipedia: Brass (dezincification, season cracking, alpha brasses)'
    type: database
    url: https://en.wikipedia.org/wiki/Brass
  - title: 'The Hendrix Group archive: stress corrosion cracking (season cracking) of brasses'
    type: report
    url: https://hghouston.com/archive/material-property-data/copper-and-copper-alloys/brasses/sc-cracking
  - title: 'ATSDR ToxFAQs: Lead'
    type: report
    url: https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=93&toxid=22
  - title: 'ATSDR ToxFAQs: Zinc (Agency for Toxic Substances and Disease Registry, U.S. CDC)'
    type: report
    url: https://www.atsdr.cdc.gov/toxfaqs/tfacts60.pdf
gaps:
  - 'The coefficient of thermal expansion is not recorded: BIKAR prints it with an exponent in the unit, which the verification step cannot match.'
  - The sheet elongation row (Elongation A50 mm) is garbled in the Righton datasheet text, so no sheet elongation is recorded.
  - Righton lists UNS C27200 with the note that it may not be a direct equivalent, so it is not recorded as a designation. No ASTM, JIS or UNS code for CW508L is printed by either source read.
  - The planner's yellow-brass and 63/37 names are not printed by either source and are not used. The sources give copper as 62.00 to 64.00 %.
  - Hardness Vickers, hardness Brinell and electrical conductivity are recorded under snake_case names that are not in the property canon. Sheet and tube proof stress is recorded as yield_strength with its printed name and no offset, because the datasheet does not state the offset.
  - Strength values carry no temper. The EN 1652 sheet and EN 12449 tube figures are as printed; no EN standard text was opened.
  - The BIKAR physical properties are not tied to a product form or temper on the page. The page's product is a drawn roundbar, but the properties are not labelled for that form.
  - The BIKAR food-industry field gives a suitability line and a No flag that conflict, so no food-contact claim is made.
  - No melting range, no outgassing, atomic-oxygen, radiation or cold-welding data, and no space-environment result for CW508L were read. The habitats-and-suits tag is not used.
  - No SDS, GHS classification or exposure limit for the alloy was read. The ATSDR zinc ToxFAQ gives metal fume fever for inhaled zinc fumes, but no source on brazing or welding fume from CW508L itself was read, so that exposure is not quantified.
  - No dezincification depth, rate or test result and no season-cracking threshold for CW508L were found. The corrosion statements are qualitative.
  - No atmospheric corrosion rate for CW508L was found in the sources read.
  - No CuZn37-specific recycling figure was found. The copper summary's statement about brass and wire-rod mills is for copper overall and is quoted in the copper supply entry.
  - Lead is not profiled as a supply subject because the sources give it at most 0.10 %.
  - No media (images) were added to this profile; no image was fetched or checked in this run.
sources:
  righton-cw508l:
    title: 'Righton and Blackburns, CW508L (CZ108) sheet and tube datasheet: chemical composition (EN 1652 and EN 12449), mechanical properties, designations, applications'
    url: https://www.rightonblackburns.co.uk/datasheets/view/Righton-Blackburns-Ltd_Copper-and-Copper-Alloys-CW508L-CZ108-Sheet_114.pdf
    kind: datasheet
    license: Supplier datasheet (cited, not reproduced)
  bikar-cw508l:
    title: 'BIKAR, brass CW508L roundbar (drawn): chemical specifications, physical properties, processing ratings, areas of application'
    url: https://my.bikar.com/en_US/products/208_303-208-303-2
    kind: datasheet
    license: Stockist product page (cited, not reproduced)
  usgs-mcs2026-copper:
    title: 'Mineral Commodity Summaries 2026: Copper'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-zinc:
    title: 'Mineral Commodity Summaries 2026: Zinc'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  wiki-brass:
    title: 'Brass (Wikipedia): dezincification-resistant brasses, season cracking, alpha brasses'
    url: https://en.wikipedia.org/wiki/Brass
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  hgh-scc:
    title: 'The Hendrix Group, Material Property Data: copper and copper alloys, brasses, stress corrosion cracking'
    url: https://hghouston.com/archive/material-property-data/copper-and-copper-alloys/brasses/sc-cracking
    kind: web
    license: Technical archive page (cited, not reproduced)
  atsdr-lead:
    title: 'ATSDR ToxFAQs: Lead (Agency for Toxic Substances and Disease Registry, U.S. CDC)'
    url: https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=93&toxid=22
    kind: report
    license: U.S. government public domain (cited, not reproduced)
  atsdr-zinc:
    title: 'ATSDR ToxFAQs: Zinc (Agency for Toxic Substances and Disease Registry, U.S. CDC)'
    url: https://www.atsdr.cdc.gov/toxfaqs/tfacts60.pdf
    kind: report
    license: U.S. government public domain (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 18
  unreachable: 0
  caveats: 4
  note: 'Values were read by an AI assistant on 2026-11-01 from the pages and PDFs named in each entry. Caveats: no temper is stated for any strength or hardness value; the proof stress is recorded under yield_strength with its printed name and no offset; hardness and electrical conductivity use names outside the property canon; the BIKAR physical properties are not tied to a product form. Supply shares are calculated from the printed USGS 2025e values, as stated in each where field.'
story:
  why: Brass CW508L is a cold-working alpha brass sold as sheet, tube and drawn bar. Righton describes good corrosion resistance, very good bending and cold heading properties, and excellent weldability. BIKAR gives a density of 8.44 g/cm3 and a thermal conductivity of 120 W/m*K at 20°C. Copper is 62.00 to 64.00 % of the alloy and zinc is the balance, and lead is listed at a maximum of 0.10 %.
  recipe:
    line: CW508L is an alpha brass, a copper-zinc alloy that Wikipedia says contains only one phase. Righton gives its composition as copper 62.00 to 64.00 %, with lead, iron, nickel, tin and aluminium at low maxima and zinc as the balance. The sources read do not describe how the sheet or tube is made.
    parts:
      - name: Copper
        symbol: Cu
        share_percent: 62
        share_high: 64
        role: Main metal and matrix of the alloy
        source: righton-cw508l
        where: Chemical Composition table, EN 1652 CW508L Brass, Copper row
      - name: Zinc
        symbol: Zn
        share_note: balance
        role: Alloying element that makes the brass; the datasheet gives zinc as the rest
        source: righton-cw508l
        where: 'Chemical Composition table, Zinc row: Balance'
      - name: Lead
        symbol: Pb
        share_percent: 0
        share_high: 0.1
        role: Trace element, a maximum of 0.10 % in both suppliers' tables
        source: righton-cw508l
        where: Chemical Composition table, Lead row
      - name: Iron
        symbol: Fe
        share_percent: 0
        share_high: 0.1
        role: Impurity limit
        source: righton-cw508l
        where: Chemical Composition table, Iron row
      - name: Nickel
        symbol: Ni
        share_percent: 0
        share_high: 0.3
        role: Impurity limit
        source: righton-cw508l
        where: Chemical Composition table, Nickel row
      - name: Tin
        symbol: Sn
        share_percent: 0
        share_high: 0.1
        role: Impurity limit
        source: righton-cw508l
        where: Chemical Composition table, Tin row
  risk_groups:
    - title: For people
      lead: The sources hold lead as a trace element in this grade. Righton and BIKAR both list a lead maximum of 0.10 %.
      level: 1
      verdict: Trace lead only
      points:
        - label: Lead in the alloy
          line: Lead is listed at a maximum of 0.10 % (Righton and BIKAR). ATSDR says lead can cause health problems in almost every organ and system in the body. No GHS code or exposure limit for this alloy was read.
    - title: If it fails
      lead: 'The failure routes in these sources are chemical: dezincification in some waters and season cracking in ammonia after cold work.'
      level: 2
      verdict: Chemical failure routes
      points:
        - label: Dezincification
          line: Wikipedia says dezincification-resistant brasses are used where high water temperatures, chlorides or soft water raise the corrosion risk. It also says NSF International requires plumbing brasses with more than 15% zinc to be dezincification-resistant. No dezincification test for CW508L was read.
        - label: Season cracking
          line: Hendrix says cold working leaves internal stress that can lead to cracking in an ammonia or amine atmosphere. The cracking is usually localised and, in simple alpha brasses, intergranular.
    - title: Handling and storage
      points:
        - label: Stress relief
          line: Stress-relieve parts after cold work, and keep them away from ammonia and amine sources.
        - label: Form and temper
          line: Specify the form and temper, because the Righton strength figures differ between sheet and tube and no temper is stated.
  uses:
    - where: Heat exchangers and radiator tanks
      line: Righton lists heat exchangers and radiator tanks as applications, and BIKAR lists water boxes for car radiators. These are terrestrial uses; no source names a spacecraft thermal system.
    - where: Hinges, locks, pins and springs
      line: Righton lists hinges, locks, pins, rivets, screws and springs, and chains and fasteners. BIKAR lists pneumatic cylinders.
    - where: Switch and contact parts
      line: Righton lists switch components and BIKAR lists contact parts. No source names a space electronics system.
  can_do:
    - label: Work it cold and hot
      line: Righton describes it as an alpha brass with good hot and cold working capabilities, with very good cold heading and bending.
    - label: Weld and braze
      line: BIKAR rates brazing and soft soldering as very good, gas and spot welding as good, and MIG and TIG as moderate, on its printed scale.
    - label: Carry heat
      value: 120 W/m*K
      benchmark: thermal_conductivity
      line: Thermal conductivity is 120 W/m*K at 20°C per BIKAR, and 142 W/m*K at 200°C.
    - label: Weight
      value: 8.44 g/cm3
      benchmark: density
      line: Density is 8.44 g/cm3 per the BIKAR physical properties table.
    - label: Strength by form
      value: 300-550 MPa tensile (sheet)
      benchmark: ultimate_tensile_strength
      line: Righton gives 300-550 MPa tensile strength for sheet from 0.2 mm to 5.00 mm and a 440 MPa minimum for tube up to 5.00 mm wall. No temper is stated.
  compare: The [copper profile](/profiles/copper/) covers the pure metal, and the free-cutting brass profile covers a leaded machining alloy. CW508L is a cold-working alpha brass with a lead maximum of 0.10 %. No source read for this profile compares it directly with either profile, so this page gives no side-by-side numbers.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Elastic modulus
      benchmark: elastic_modulus
  handling:
    - 'Specify the form and temper: Righton gives different strength figures for sheet and tube, and no temper for either.'
    - Stress-relieve after cold work (pressing, spinning, drawing, bending), and keep parts out of ammonia and amine atmospheres.
    - 'Choose the joining process with BIKAR''s ratings: brazing and soft soldering are very good, while MIG and TIG are moderate.'
  good_for:
    - Formed sheet parts, tube and drawn bar that need good cold working and bending.
    - Brazed or soldered assemblies, where BIKAR rates brazing and soft soldering as very good.
    - Fittings and hardware in water service where the suppliers report good resistance, provided the dezincification and season-cracking risks below are handled.
  watch_out:
    - 'Dezincification: Wikipedia says plumbing brasses with more than 15% zinc need dezincification resistance, and CW508L has zinc as its balance.'
    - 'Season cracking: after cold work, an ammonia or amine atmosphere can crack the part, usually along the line of tensile stress.'
    - 'Temper and form: no temper is stated for any strength value, and the sheet and tube figures differ.'
    - The physical properties come from a stockist's tables, not from a standard test report.
  verdict: CW508L (CuZn37) is a cold-working alpha brass with 62.00 to 64.00 % copper and zinc as the balance. Its density is 8.44 g/cm3 and its sheet tensile strength is 300-550 MPa, with no temper stated. Both suppliers report good corrosion resistance to water and salts, but the sources give no dezincification or season-cracking test result for this grade, so those risks rest on the Wikipedia and Hendrix statements.