spore: profile
id: maraging-steel-250
spore_version: 0.2
family: maraging-steels
name: Maraging 250 steel
abbreviation: Maraging 250
role: ultra-high-strength structural steel
category: metals
type: steels-and-stainless
summary: |
  Maraging 250 steel is an 18% nickel, cobalt-strengthened steel (C-type) that is aged at a low temperature to reach its strength. Aged at about 480 °C for about 3 to 6 hours (Sakysteel), it has a tensile strength of 1720 to 1860 MPa and a density of 8.0 to 8.1 g/cm3 (Sakysteel, approximate values). Its solution-annealed hardness is 30 to 35 HRC (Sakysteel), so it can be machined before it is aged. Corrosion resistance was not found in any source we hold.
best_for: Ultra-high-strength structural parts that are machined soft and then aged, such as rocket motor cases and landing gear components
weakest_at: Corrosion behaviour is not documented in any source we hold, and the sources give properties that depend on bar size, test direction and aging cycle
identity:
  formula: Fe-based alloy with nominal Ni 18.50, Co 7.50, Mo 4.80, Ti 0.40, Al 0.10 (SSA nominal, wt %); reference ranges Ni 17.00 to 19.00, Co 7.00 to 8.50, Mo 4.60 to 5.20, Ti 0.30 to 0.50, Al 0.05 to 0.15 (Dynamic Metals), balance Fe
  source: dmi-maraging-250
  where: Chemical Composition table (Dynamic Metals slide, wt %); SSA Chemical Composition table (Nominal %)
  designations:
    - system: UNS
      code: K92890
      source: sakysteel-maraging-250
      where: Product table, UNS line
    - system: AMS
      code: '6512'
      source: ssa-maraging-250
      where: Page title and product description (AMS 6512 primary bar and forging-stock specification)
    - system: EN
      code: '1.6359'
      source: sakysteel-maraging-250
      where: EN/European reference line (W.Nr. 1.6359)
    - system: EN name
      code: X2NiCoMo18-8-5
      source: sakysteel-maraging-250
      where: Product parameters table, X2NiCoMo18-8-5 reference
    - system: BS
      code: S162
      source: sakysteel-maraging-250
      where: British reference line (BS S162 / DTD 5212)
    - system: ASTM
      code: A538
      note: printed as ASTM A 538; listed on the Standards line
      source: dmi-maraging-250
      where: Standards line
    - system: Trade name
      code: VASCOMAX
      note: printed as VASCOMAX® 250 on the SSA page (the 250 is the grade number)
      source: ssa-maraging-250
      where: Product name line
tags:
  environments: []
  stresses: []
  applications:
    - structures
    - propulsion-and-tanks
    - mechanisms
properties:
  - benchmark: density
    label: Density, Maraging 250 bar
    value: 8
    value_high: 8.1
    bound: range
    unit: g/cm3
    scope: material
    conditions:
      form: bar as printed (no form or temper stated beyond the cited page)
      temperature: room temperature
    method: Approximate range printed on a supplier mechanical and heat-treatment table
    status: ground
    note: Printed as Approx. 8.0-8.1 g/cm3 (Sakysteel). Dynamic Metals prints 0.289 lbs./cu. In. without a stated condition.
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Density row
  - benchmark: elastic_modulus
    label: Elastic modulus, Maraging 250
    value: 185
    value_high: 195
    bound: range
    unit: GPa
    scope: material
    conditions:
      temperature: room temperature
      condition: as printed for the aged condition
    method: Approximate range printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Elastic Modulus row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, aged Maraging 250
    value: 1720
    value_high: 1860
    bound: range
    unit: MPa
    scope: material
    conditions:
      condition: aged
      orientation: not stated on the page
      size: results depend on bar size, test orientation, melting route and aging treatment (page text)
    method: Approximate range printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Tensile Strength row
  - benchmark: yield_strength
    label: 0.2% yield strength, aged Maraging 250 (minimum reference)
    value: 1655
    bound: lower
    unit: MPa
    scope: material
    conditions:
      condition: aged
      offset: 0.2%
      basis: minimum reference value printed on the page
    method: Minimum reference printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, 0.2% Yield Strength row
  - benchmark: yield_strength
    label: Yield strength, Maraging 250 (minimum after heat treatment)
    value: 240
    bound: lower
    unit: ksi
    scope: material
    conditions:
      condition: after heat treatment as printed (aging cycle not named)
      orientation: not stated
    method: Minimum printed on a slide of mechanical properties
    status: ground
    note: Dynamic Metals gives 240 ksi as a minimum; Sakysteel gives 1655 MPa as a minimum reference. The two are consistent in magnitude but use different units and conditions.
    source: dmi-maraging-250
    where: Mechanical Properties (Minimum, After Heat Treatment) table, Yield Strength row
  - benchmark: elongation
    label: Elongation, aged Maraging 250
    value: 5
    value_high: 8
    bound: range
    unit: '%'
    scope: material
    conditions:
      condition: aged
      size: size dependent, as printed
    method: Approximate range printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Elongation row
  - benchmark: elongation
    label: Elongation, Maraging 250 (minimum after heat treatment)
    value: 6
    bound: lower
    unit: '%'
    scope: material
    conditions:
      condition: after heat treatment as printed (aging cycle not named)
    method: Minimum printed on a slide of mechanical properties
    status: ground
    source: dmi-maraging-250
    where: Mechanical Properties (Minimum, After Heat Treatment) table, Elongation row
  - benchmark: hardness_rockwell_c
    label: Hardness, aged Maraging 250
    value: 48
    value_high: 52
    bound: range
    unit: HRC
    scope: material
    conditions:
      condition: aged
    method: Approximate range printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Hardness row
  - benchmark: hardness_rockwell_c
    label: Hardness, Maraging 250 (minimum after heat treatment)
    value: 48
    bound: lower
    unit: Rc
    scope: material
    conditions:
      condition: after heat treatment as printed (aging cycle not named)
    method: Minimum printed on a slide of mechanical properties
    status: ground
    source: dmi-maraging-250
    where: Mechanical Properties (Minimum, After Heat Treatment) table, Hardness row
  - benchmark: hardness_rockwell_c
    label: Hardness, solution-annealed Maraging 250
    value: 30
    value_high: 35
    bound: range
    unit: HRC
    scope: material
    conditions:
      condition: solution annealed
    method: Approximate range printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Annealed Hardness row
  - benchmark: hardness_rockwell_c
    label: Hardness, as-shipped annealed and descaled Maraging 250
    value: 30
    value_high: 34
    bound: range
    unit: Rc
    scope: material
    conditions:
      condition: annealed and descaled, as shipped
    method: Range printed on a slide
    status: ground
    source: dmi-maraging-250
    where: As-shipped condition line
  - benchmark: charpy_impact_energy
    label: Charpy V-notch energy, Maraging 250 (minimum after heat treatment)
    value: 15
    bound: lower
    unit: ft/lbs
    scope: material
    conditions:
      condition: after heat treatment as printed (aging cycle not named)
      notch: V-notch
    method: Minimum printed on a slide of mechanical properties
    status: ground
    source: dmi-maraging-250
    where: Mechanical Properties (Minimum, After Heat Treatment) table, Charpy V-notch row
  - benchmark: reduction_of_area
    label: Reduction of area, Maraging 250 (minimum after heat treatment)
    value: 50
    bound: lower
    unit: '%'
    scope: material
    conditions:
      condition: after heat treatment as printed (aging cycle not named)
    method: Minimum printed on a slide of mechanical properties
    status: ground
    source: dmi-maraging-250
    where: Mechanical Properties (Minimum, After Heat Treatment) table, Reduction of Area row
  - benchmark: solution_treatment_temperature
    label: Solution treatment temperature, Maraging 250
    value: 815
    value_high: 830
    bound: range
    unit: °C
    scope: material
    conditions:
      step: solution treatment
      cooling: air cooled
    method: Approximate range printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Solution Treatment row
  - benchmark: aging_temperature
    label: Aging temperature, Maraging 250 (typical)
    value: 480
    unit: °C
    scope: material
    conditions:
      step: aging
      duration: about 3 to 6 hours as printed
      cooling: air cooled
    method: Typical value printed on a supplier table
    status: ground
    source: sakysteel-maraging-250
    where: Mechanical and Heat-Treatment Properties table, Typical Aging row
  - benchmark: aging_temperature
    label: Aging temperature, Maraging 250 (non-die-casting cycle)
    value: 900
    unit: F
    scope: material
    conditions:
      step: aging
      tolerance: plus or minus 10 F as printed
      duration: 6 hours
      cooling: cool in room air
    method: Cycle printed on a slide
    status: ground
    source: dmi-maraging-250
    where: Heat Treatment (Slide 1), non-die-casting applications
  - benchmark: hardness_rockwell_c
    label: Hardness, aged Maraging 250 (after 900/925 F for 6 hours)
    value: 48
    value_high: 52
    bound: range
    unit: Rc
    scope: material
    conditions:
      condition: aged at 900/925 F for 6 hours
    method: Range printed in a heat-treatment table on a supplier page
    status: ground
    source: ssa-maraging-250
    where: Heat Treatment / Aging table, Resulting Hardness row
  - benchmark: hardness_rockwell_c
    label: Hardness, solution-annealed Maraging 250 (SSA)
    value: 30
    value_high: 35
    bound: range
    unit: Rc
    scope: material
    conditions:
      condition: solution annealed
    method: Range printed on a supplier page
    status: ground
    source: ssa-maraging-250
    where: Heat Treatment / Aging section, solution annealed condition line
  - benchmark: aging_temperature
    label: Aging temperature, Maraging 250 (SSA cycle)
    value: 900
    value_high: 925
    bound: range
    unit: F
    scope: material
    conditions:
      step: aging
      duration: 6 hours
    method: Temperature range printed in a heat-treatment table on a supplier page
    status: ground
    source: ssa-maraging-250
    where: Heat Treatment / Aging table, Temperature row
corrosion:
  - environment: Not stated in any source we hold
    headline: Corrosion resistance of Maraging 250 was not found in any source we hold, so no corrosion rating is given.
    effect: Three supplier pages and one slide cover mechanical and physical properties, heat treatment and applications. None gives a corrosion test, a corrosion rate or a statement on resistance to a named medium. Titanium alloys can substitute for nickel-base alloys in corrosive environments according to USGS, but that statement concerns other materials.
    rating: unknown
    conditions:
      basis: absence of any corrosion data in the cited pages
    source: ssa-maraging-250
    where: Whole page checked; no corrosion section
risks:
  hazards:
    - text: The alloy itself has no GHS entry we could read. The hazard entries below are for cobalt metal, a constituent of the alloy, and do not measure this grade. PubChem's aggregated cobalt entry lists 'Harmful if swallowed', 'May cause an allergic skin reaction', 'Causes serious eye irritation', 'Fatal if inhaled', 'May cause allergy or asthma symptoms or breathing difficulties if inhaled', 'Suspected of causing genetic defects', 'May cause cancer' and 'May damage fertility; Suspected of damaging the unborn child'.
      ghs:
        - H302
        - H317
        - H319
        - H330
        - H334
        - H341
        - H350
        - H360Fd
      source: pubchem-cobalt
      where: GHS Classification section, aggregated entry, CID 104730 (cobalt)
    - text: The same PubChem entry lists 'Very toxic to aquatic life' and 'Toxic to aquatic life with long lasting effects' for cobalt metal, with a signal word of Danger on the aggregated entry.
      ghs:
        - H400
        - H410
        - H411
        - H413
      source: pubchem-cobalt
      where: GHS Classification section, aggregated entry, CID 104730 (cobalt)
  failure_risks:
    - mode: Properties depend on the aging cycle
      trigger: Aging away from the printed cycle (900 F plus or minus 10 F for 6 hours in the Dynamic Metals non-die-casting route)
      consequence: Sakysteel says results depend on 'bar size, test orientation, melting route, and aging treatment', so a strength value from one cycle cannot be assumed for another.
      severity: moderate
      source: sakysteel-maraging-250
      where: Chemical and heat-treatment notes; Mechanical and Heat-Treatment Properties table
    - mode: Test direction not stated on the supplier data
      trigger: Using a property value taken from a bar or slide without its test direction
      consequence: Dynamic Metals states that the page does not specify test direction (longitudinal or transverse) for any property, so a value may not apply to the orientation a part is loaded in.
      severity: low
      source: dmi-maraging-250
      where: Mechanical Properties (Minimum, After Heat Treatment) table
  handling:
    - text: 'Die-casting route, as printed: ''anneal at 1500-1525 F for 1 hour per inch of thickness'' after rough machining, then ''age at 980-1000 F for 6 hours'' after finish machining.'
      source: dmi-maraging-250
      where: Heat Treatment (Slide 1), die-casting applications
    - text: Supplied in the annealed and descaled condition. Sakysteel prints a solution-annealed hardness of 30 to 35 HRC, and Dynamic Metals prints 30/34 Rc as shipped.
      source: sakysteel-maraging-250
      where: Annealed Hardness row; Dynamic Metals As-shipped condition line
uses:
  - application: propulsion-and-tanks
    device: Missile and rocket motor cases
    example: Dynamic Metals lists missile and rocket motor cases among the applications for MARAGING (C) 250.
    source: dmi-maraging-250
    where: Listed Applications
  - application: structures
    device: Aircraft landing gear components
    example: Sakysteel lists aircraft landing gear components among the applications for Maraging 250.
    source: sakysteel-maraging-250
    where: Listed Applications
  - application: structures
    device: Aerospace structural and component parts
    example: SSA lists aerospace, structural, component and tooling applications for Maraging 250, with critical parts among them.
    source: ssa-maraging-250
    where: Applications (as listed)
  - application: mechanisms
    device: High-performance shafting, gears and fasteners
    example: Dynamic Metals lists high-performance shafting, gears and fasteners among its applications for MARAGING (C) 250.
    source: dmi-maraging-250
    where: Listed Applications
supply:
  - subject: Cobalt (a main alloying element)
    abundance: Not stated in the sources we hold for this profile.
    producers:
      - country: Congo (Kinshasa)
        share_percent: 73
        year: 2025
      - country: Indonesia
        share_percent: 14
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (page lists cobalt)
        listed: true
      - list: European Commission critical raw materials page (lists Cobalt)
        listed: true
    recycling: 'USGS: cobalt content of purchased scrap represented 25% of estimated cobalt consumption in 2025.'
    substitutes:
      - 'USGS: depending on the application, substitution for cobalt could result in a loss in product performance or increased cost.'
    source: usgs-mcs2026-cobalt
    where: Events, Trends, and Issues (Congo and Indonesia shares, printed); World Mine Production table (world total 310,000 metric tons in 2025, cobalt content); Recycling; Substitutes
  - subject: Nickel (main alloying element)
    producers: []
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (page lists nickel)
        listed: true
      - list: European Commission critical raw materials page (nickel included as a strategic raw material)
        listed: true
    recycling: 'USGS: nickel recovered from scrap accounted for approximately 60% of apparent consumption in 2025.'
    substitutes:
      - 'USGS: titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments.'
    source: usgs-mcs2026-nickel
    where: World Mine Production and Reserves table (world total 3,900,000 metric tons in 2025, nickel content); Events (3.9 million tons in 2025); Recycling; Substitutes
  - subject: Molybdenum (a main alloying element)
    producers: []
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (molybdenum not listed)
        listed: false
      - list: European Commission critical raw materials page (molybdenum not listed)
        listed: false
    recycling: 'USGS: molybdenum may be recycled as much as 30% of apparent supply as part of steel and other scrap.'
    substitutes: []
    source: usgs-mcs2026-molybdenum
    where: Recycling paragraph; Events (China, Chile, the United States, Peru and Mexico accounted for 90% of total global production); World Mine Production table (world total 260,000 metric tons in 2025, molybdenum content)
  - subject: Titanium sponge (titanium alloying element)
    producers: []
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (page lists titanium, used in metal alloys)
        listed: true
      - list: European Commission critical raw materials page (titanium metal listed)
        listed: true
    recycling: 'USGS: limited responses to voluntary surveys mean the consumption data for titanium scrap metal are incomplete.'
    substitutes:
      - 'USGS: few materials possess titanium metal''s strength-to-weight ratio and corrosion resistance.'
    source: usgs-mcs2026-titanium
    where: World Sponge Metal Production table (world total 370,000 metric tons in 2025; China 260,000); Recycling; Substitutes
media: []
documents:
  - title: 'Service Steel Aerospace: Maraging 250 (AMS 6512) product and mechanical properties page'
    type: datasheet
    url: https://ssa-corp.com/he/maraging-250-AMS-6512.php
    year: 2026
  - title: 'Sakysteel: Maraging 250 steel round bar product page'
    type: datasheet
    url: https://m.sakysteel.com/maraging-250-steel-round-bar.html
    year: 2026
  - title: 'Dynamic Metals International: MARAGING (C) 250 slide (SlideShare)'
    type: datasheet
    url: https://www.slideshare.net/slideshow/maraging-250-spec/48297132
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Cobalt'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Molybdenum'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Titanium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
    year: 2026
  - title: 'PubChem: Cobalt (CID 104730), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/104730
    year: 2026
gaps:
  - 'Corrosion resistance of Maraging 250 in any medium: not found in any source we hold. The corrosion entry is rated unknown on purpose.'
  - 'Fracture toughness: Dynamic Metals prints ''75 KIC'' with no unit, so the value was left out.'
  - 'Coefficient of thermal expansion: the pages print ''5.6 x 10-6'' with the exponent in a non-standard form, so the value was left out. Dynamic Metals gives 5.6 x 10 -6 in/in. F for 70 to 900 F.'
  - 'Modulus: SSA prints ''27.0 x 10-6 psi'', which looks like a typo for 10^6 and is not used; the Sakysteel range in GPa is recorded instead.'
  - 'Test direction (longitudinal or transverse) for any property: not stated on any page.'
  - No SDS or safety page for Maraging 250 itself was found. Hazard entries are for cobalt metal, a constituent.
  - Nickel, molybdenum and titanium producer shares by country were not printed in the pages used, so supply rows give the world totals, not shares.
  - UNS and EN designations were checked against the printed pages; the 18Ni(250) name is not printed in any source, so only 18Ni250 is used, as a grade name on the Sakysteel page.
  - 'Seven Dynamic Metals values and its ASTM A 538 designation could not be machine-checked: the SlideShare page returned no text to verify-values. They were read in this run with WebFetch and are flagged for a manual check.'
  - Peer-reviewed or open-access papers on Maraging 250 were not reached in this run; the properties rest on supplier pages and one slide.
sources:
  ssa-maraging-250:
    title: Maraging 250 (AMS 6512), Service Steel Aerospace product page
    id: SSA page, maraging-250-AMS-6512
    url: https://ssa-corp.com/he/maraging-250-AMS-6512.php
    year: 2026
    kind: web
    license: supplier page, cited not reproduced
  sakysteel-maraging-250:
    title: Maraging 250 steel round bar, Sakysteel product page
    id: Sakysteel product page
    url: https://m.sakysteel.com/maraging-250-steel-round-bar.html
    year: 2026
    kind: web
    license: supplier page, cited not reproduced
  dmi-maraging-250:
    title: MARAGING (C) 250, Dynamic Metals International slide (SlideShare)
    id: SlideShare 48297132
    url: https://www.slideshare.net/slideshow/maraging-250-spec/48297132
    year: 2026
    kind: datasheet
    license: slide, cited not reproduced
  usgs-mcs2026-cobalt:
    title: Mineral Commodity Summaries 2026, Cobalt
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-nickel:
    title: Mineral Commodity Summaries 2026, Nickel
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-molybdenum:
    title: Mineral Commodity Summaries 2026, Molybdenum
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-titanium:
    title: Mineral Commodity Summaries 2026, Titanium
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-titanium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pubchem-cobalt:
    title: PubChem compound record, Cobalt (CID 104730), GHS classification
    id: CID 104730
    url: https://pubchem.ncbi.nlm.nih.gov/compound/104730
    year: 2026
    kind: database
    license: public domain (NCBI)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: USGS final 2025 list
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
  ec-crm:
    title: Critical raw materials (European Commission page, 34 materials)
    id: European Commission CRM page
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2024
    kind: web
    license: European Commission web page
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 19
  unreachable: 0
  caveats: 2
  note: Written by an AI assistant on 2026-11-01 from pages fetched in that run. Supplier values are approximate or minimum values as printed; no test-certificate values were available.
story:
  recipe:
    line: Maraging 250 is an iron-nickel-cobalt-molybdenum steel. Suppliers supply it in the solution-annealed condition and age it at a low temperature (Sakysteel prints about 480 °C for about 3 to 6 hours). Supplier pages describe it as double vacuum melted by VIM followed by VAR.
    parts:
      - name: Nickel
        symbol: Ni
        share: 18.50 nominal (SSA); 17.00 to 19.00 (Dynamic Metals), wt %
        role: Main alloying element. The Sakysteel page calls it an 18% nickel, cobalt strengthened steel (C-type).
      - name: Cobalt
        symbol: Co
        share: 7.50 nominal (SSA); 7.00 to 8.50 (Dynamic Metals), wt %
        role: Cobalt strengthened steel (SSA wording).
      - name: Molybdenum
        symbol: Mo
        share: 4.80 nominal (SSA); 4.60 to 5.20 (Dynamic Metals), wt %
        role: Alloying element listed in both composition tables.
      - name: Titanium
        symbol: Ti
        share: 0.40 nominal (SSA); 0.30 to 0.50 (Dynamic Metals), wt %
        role: Alloying element listed in both composition tables.
      - name: Aluminium
        symbol: Al
        share: 0.10 nominal (SSA); 0.05 to 0.15 (Dynamic Metals), wt %
        role: Alloying element listed in both composition tables.
      - name: Iron
        symbol: Fe
        share: balance
        role: Balance of the composition in both sources.
  risk_groups:
    - title: For people
      level: 0
      verdict: No alloy hazard entry found
      lead: No safety data sheet or GHS entry for Maraging 250 itself was found. The entries below are for cobalt metal, a constituent.
      points:
        - label: Cobalt metal
          line: PubChem's aggregated entry for cobalt metal lists statements including 'May cause cancer', 'Fatal if inhaled' and 'Suspected of causing genetic defects'. These describe the element, not this alloy.
        - label: Dust and fume
          line: No exposure limit or dust data for this grade was found in the sources we hold.
    - title: If a part fails in service
      lead: The sources give no failure test data for this grade.
      points:
        - label: Aging route
          line: Properties depend on the aging cycle, bar size, test orientation and melting route, according to Sakysteel.
    - title: Handling and processing
      points:
        - label: Die casting route
          line: Dynamic Metals prints an anneal of 1500-1525 F for 1 hour per inch of thickness after rough machining, then aging at 980-1000 F for 6 hours after finish machining.
        - label: Annealed state
          line: The as-shipped condition is annealed and descaled, at 30/34 Rc (Dynamic Metals) or 30/35 Rc (SSA).
  why: Maraging 250 steel (also called VASCOMAX 250 and specified as AMS 6512) is an ultra-high-strength steel. It is supplied in the annealed, descaled condition. The Dynamic Metals die-casting route anneals after rough machining and ages after finish machining. Service Steel Aerospace describes the grade as an 18% nickel, cobalt strengthened steel. Suppliers list it for rocket motor cases, landing gear components, shafts, gears, fasteners and tooling.
  uses:
    - where: Rocket motor cases and missiles
      line: Dynamic Metals lists missile and rocket motor cases among the applications for MARAGING (C) 250. The source is a supplier slide, not a flight record.
    - where: Landing gear
      line: Sakysteel lists aircraft landing gear components among its applications for Maraging 250. SSA lists aerospace, structural, component and tooling applications in the same way.
    - where: Shafts, gears and fasteners
      line: Dynamic Metals lists high-performance shafting, gears and fasteners. No space flight use was found in the sources we hold.
  can_do:
    - label: Strength
      benchmark: yield_strength
      value: 240 ksi
      line: After heat treatment Dynamic Metals gives a minimum yield strength of 240 ksi. Sakysteel gives a minimum reference of 1655 MPa for the aged condition, with a tensile range of 1720 to 1860 MPa.
    - label: Machinability before aging
      benchmark: hardness_rockwell_c
      value: 30 to 35 HRC
      line: In the solution-annealed condition the steel is 30 to 35 HRC according to Sakysteel, which is soft enough to machine before it is aged to 48 to 52 HRC.
    - label: Density
      benchmark: density
      value: 8.0 to 8.1 g/cm3
      line: The density is printed as an approximate 8.0 to 8.1 g/cm3 (Sakysteel). No other density value was read in a source that states its condition.
  compare: The sources give Maraging 250 a density of 8.0 to 8.1 g/cm3 (Sakysteel, approximate) and a solution-annealed hardness of 30 to 35 HRC, against 48 to 52 HRC when aged (Sakysteel). The USGS says that titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments, but no source held gives a corrosion rating for Maraging 250, so a like-for-like corrosion comparison cannot be made from this profile.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Tensile strength
      benchmark: ultimate_tensile_strength
    - label: Yield strength
      benchmark: yield_strength
  handling:
    - Anneal before final machining, using the printed Dynamic Metals die-casting route, or follow the supplier's own cycle.
    - The alloy is supplied annealed and descaled. Check the aging cycle against the mill certificate for the bar size.
    - No hazard data sheet for the alloy was found, and no dust exposure limit for this grade was found in the sources we hold.
  good_for:
    - Very high strength in a machinable steel, with a yield strength of 240 ksi minimum after heat treatment (Dynamic Metals).
    - Parts that need strength after a low-temperature aging step, such as rocket motor cases and landing gear components (Sakysteel, Dynamic Metals).
  watch_out:
    - No corrosion data was found for this grade in any source we hold.
    - Property values depend on bar size, test direction and aging cycle, and the test direction is not stated on any page.
    - The cobalt in the alloy carries its own hazard statements, including 'May cause cancer', from PubChem.
  verdict: Maraging 250 is a machinable high-strength steel for rocket and landing gear parts, but the corrosion behaviour needs a supplier certificate or a test before use.