ASTM A36 structural carbon steel A36 (UNS K02600)

spore: profile
id: steel-a36
spore_version: 0.2
family: carbon-and-alloy-steels
name: ASTM A36 structural carbon steel
abbreviation: A36 (UNS K02600)
role: structural steel
category: metals
type: steels-and-stainless
summary: |
  ASTM A36 is the common low-carbon structural steel of the United States. It is iron with at most 0.26 percent carbon, 1.03 percent manganese and small amounts of silicon, phosphorus, sulfur and copper. Plate under 8 in thick has a minimum yield strength of 36 ksi (250 MPa) and a tensile strength of 58 to 80 ksi (400 to 550 MPa). It is readily welded and bolted, and it is sold as plate, bars, shapes and girders. Unprotected, it rusts in ordinary outdoor air, so it is normally painted or galvanized.
best_for: Welded and bolted structural frames, girders and shapes that will be painted or galvanized
weakest_at: Rusts outdoors and corrodes first when it touches copper or tin in a wet electrolyte; minimum strength falls above 650 °F (343 °C)
identity:
  formula: Fe balance; C 0.26, Si 0.40, Mn 1.03, P 0.04, S 0.05, Cu 0.20 maximum (wt%, shapes; Wikipedia table, Fe 98.0 as printed). Flanges over 3 in need Mn 0.85 to 1.35 and Si 0.15 to 0.40
  source: wiki-a36
  where: Chemical composition table for shapes and the note below it (Wikipedia, A36 steel)
  designations:
    - system: UNS
      code: K02600
      source: wiki-a36
      where: Lead section, sentence on the A36 (UNS K02600) standard
    - system: ASTM
      code: A36
      source: ssab-a36
      where: Page title and first product paragraph (ASTM A36 specification)
tags:
  environments: []
  stresses: []
  applications:
    - structures
properties:
  - benchmark: yield_strength
    label: Minimum yield strength, mill plate 0.100 to 6.00 in (SSAB datasheet)
    value: 36
    bound: lower
    unit: ksi
    scope: material
    conditions:
      form: mill plate and temper-leveled plate (SSAB product table)
      thickness: 0.100 to 6.00 in (2.54 to 152 mm)
      test: transverse tension test per ASTM A6, as printed by SSAB
      basis: minimum as printed in the SSAB ASTM A36 mechanical properties table
    method: Mechanical properties table, minimum value as printed
    status: ground
    source: ssab-a36
    where: Mechanical Properties table, Yield strength (min ksi) row
  - benchmark: yield_strength
    label: Minimum yield strength, plates, bars and shapes under 8 in (Wikipedia)
    value: 250
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: plates, bars and shapes
      thickness: less than 8 in (203 mm)
      basis: minimum as printed with its MPa conversion; the article cites the Steel Construction Manual
    method: Properties section, minimum value as printed
    status: ground
    source: wiki-a36
    where: Properties section, first paragraph (minimum yield strength)
  - benchmark: yield_strength
    label: Minimum yield strength, plates over 8 in thick (Wikipedia)
    value: 220
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: plates
      thickness: more than 8 in (203 mm)
      basis: Wikipedia prints 32 ksi (220 MPa) for plates thicker than 8 inches
    method: Properties section, minimum value as printed
    status: ground
    source: wiki-a36
    where: Properties section, first paragraph (plates thicker than 8 inches)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength range, mill plate 0.100 to 6.00 in (SSAB datasheet)
    value: 58
    value_high: 80
    bound: range
    unit: ksi
    scope: material
    conditions:
      form: mill plate and temper-leveled plate (SSAB product table)
      thickness: 0.100 to 6.00 in (2.54 to 152 mm)
      test: transverse tension test per ASTM A6, as printed by SSAB
      basis: specified range as printed (58 minimum, 80 maximum)
    method: Mechanical properties table, minimum and maximum as printed
    status: ground
    source: ssab-a36
    where: Mechanical Properties table, Tensile strength row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength range, plates, bars and shapes (Wikipedia)
    value: 400
    value_high: 550
    bound: range
    unit: MPa
    scope: material
    conditions:
      form: plates, bars and shapes
      thickness: less than 8 in (203 mm); plates over 8 in carry the same range
      basis: Wikipedia prints 58 to 80 ksi (400 to 550 MPa)
    method: Properties section, range as printed with its MPa conversion
    status: ground
    source: wiki-a36
    where: Properties section, first paragraph (ultimate tensile strength)
  - benchmark: ultimate_tensile_strength
    label: Minimum ultimate strength at 700 °F (Wikipedia)
    value: 370
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: bars and shapes
      thickness: not stated
      temperature: 700 °F (371 °C)
      basis: above 650 °F (343 °C) the minimum falls from 58 ksi (400 MPa); Wikipedia prints 54 ksi (370 MPa) at 700 °F (371 °C)
    method: Properties section, minimum strength at temperature as printed
    status: ground
    source: wiki-a36
    where: Properties section, sentence on bars and shapes above 650 °F
  - benchmark: ultimate_tensile_strength
    label: Minimum ultimate strength at 800 °F (Wikipedia)
    value: 260
    bound: lower
    unit: MPa
    scope: material
    conditions:
      form: bars and shapes
      thickness: not stated
      temperature: 800 °F (427 °C)
      basis: Wikipedia prints 37 ksi (260 MPa) at 800 °F (427 °C)
    method: Properties section, minimum strength at temperature as printed
    status: ground
    source: wiki-a36
    where: Properties section, sentence on bars and shapes above 650 °F
  - benchmark: elongation
    label: Minimum elongation in 2 in, mill plate (SSAB datasheet)
    value: 21
    bound: lower
    unit: '%'
    scope: material
    conditions:
      form: mill plate and temper-leveled plate (SSAB product table)
      thickness: 0.100 to 6.00 in (2.54 to 152 mm)
      gauge: 2 in
      basis: 'SSAB footnote: for plates wider than 24 in the requirement is reduced by two percentage points'
    method: Mechanical properties table, minimum as printed
    status: ground
    source: ssab-a36
    where: Mechanical Properties table, Elongation in 2 in (min %) row
  - benchmark: elongation
    label: Minimum elongation in 8 in, mill plate (SSAB datasheet)
    value: 18
    bound: lower
    unit: '%'
    scope: material
    conditions:
      form: mill plate and temper-leveled plate (SSAB product table)
      thickness: 0.100 to 6.00 in (2.54 to 152 mm)
      gauge: 8 in
      basis: 'SSAB footnote: for plates wider than 24 in the requirement is reduced by two percentage points'
    method: Mechanical properties table, minimum as printed
    status: ground
    source: ssab-a36
    where: Mechanical Properties table, Elongation in 8 in (min %) row
  - benchmark: density
    label: Density of A36 (Wikipedia)
    value: 7.8
    unit: g/cm3
    scope: material
    conditions:
      form: not stated (general A36)
      thickness: not stated
      temperature: not stated
      basis: Wikipedia prints 0.28 lb/in3 (7.8 g/cm3)
    method: Properties section, value in g/cm3 as printed
    status: ground
    source: wiki-a36
    where: Properties section, first paragraph (density)
  - benchmark: elastic_modulus
    label: Young's modulus of A36 (Wikipedia)
    value: 200
    unit: GPa
    scope: material
    conditions:
      form: not stated (general A36)
      thickness: not stated
      temperature: not stated
      basis: Wikipedia prints 29,000 ksi (200 GPa)
    method: Properties section, value in GPa as printed
    status: ground
    source: wiki-a36
    where: Properties section, Young's modulus sentence
  - benchmark: shear_modulus
    label: Shear modulus of A36 (Wikipedia)
    value: 79.3
    unit: GPa
    scope: material
    conditions:
      form: not stated (general A36)
      thickness: not stated
      temperature: not stated
      basis: Wikipedia prints 11,500 ksi (79.3 GPa)
    method: Properties section, value in GPa as printed
    status: ground
    source: wiki-a36
    where: Properties section, Poisson's ratio and shear modulus sentence
  - benchmark: poissons_ratio
    label: Poisson's ratio of A36 (Wikipedia)
    value: 0.26
    unit: '-'
    scope: material
    conditions:
      form: not stated (general A36)
      thickness: not stated
      temperature: not stated
      basis: Wikipedia prints 0.26 with no temperature or form
    method: Properties section, value as printed
    status: ground
    source: wiki-a36
    where: Properties section, Poisson's ratio and shear modulus sentence
  - benchmark: electrical_resistivity
    label: Electrical resistivity of A36 (Wikipedia)
    value: 0.142
    unit: μΩ·m
    scope: material
    conditions:
      form: not stated (general A36)
      thickness: not stated
      temperature: 68 °F (20 °C)
      basis: Wikipedia calls it electrical resistance and prints 0.142 μΩm at 20 °C; the unit is a resistivity
    method: Properties section, value as printed
    status: ground
    source: wiki-a36
    where: Properties section, electrical resistance sentence
corrosion:
  - environment: Outdoor air with moisture, unprotected steel
    headline: Plain steel such as A36 rusts in ordinary outdoor air unless it is protected.
    effect: Wikipedia states that structural steel cannot be exposed to the environment without suitable protection, because moisture or contact with water causes oxidation that compromises the structure.
    rating: moderate
    conditions:
      exposure: outdoor, moist air
      form: structural steel (general)
    source: wiki-structural
    where: Paragraph on exposure and protection (Structural steel)
  - environment: Uncoated or painted plain steel compared with weathering steel
    headline: Weathering steel forms a stable rust layer that removes the need for paint, while painted weathering steel is no more corrosion-resistant than conventional steel.
    effect: The protective patina needs the wetted surface to dry, and a small paint failure can start a localized attack (Wikipedia). A36 is conventional steel, not a weathering grade.
    rating: moderate
    conditions:
      exposure: outdoor
      comparison: weathering steel versus conventional steel
    source: wiki-weathering
    where: Properties section (patina) and the railcar history paragraph
  - environment: Steel coupled to copper or tin in a wet electrolyte
    headline: Steel is the more reactive metal in these couples and corrodes faster where it touches the more noble metal.
    effect: Galvanic corrosion needs an electrolyte and an electrical path. Wikipedia gives a marina example where a steel and copper couple acts as a battery of about 0.5 V, and says that when a tin coating on steel is broken the steel beneath is attacked at once.
    rating: moderate
    conditions:
      electrolyte: wet, salty or moist environment
      couple: steel with copper or tin
    source: wiki-galvanic
    where: Mechanism paragraph; tin can example; marina example
  - environment: Zinc-coated (galvanized) steel
    headline: The zinc coating corrodes first and protects the steel until the zinc is used up.
    effect: Wikipedia states that galvanizing protects the steel base metal by sacrificial anodic action, and that the underlying steel is not attacked even when the zinc coating is broken.
    rating: low
    conditions:
      coating: zinc
    source: wiki-galvanic
    where: Galvanized iron example; mitigation paragraph on galvanizing
risks:
  hazards:
    - text: 'PubChem aggregated GHS for elemental manganese (Danger): H360 (may damage fertility or the unborn child), H370 (causes damage to organs), H372 (causes damage to organs through prolonged or repeated exposure) and H411 (toxic to aquatic life with long lasting effects). The record covers the element, not the solid A36 steel, which contains manganese up to 1.03 % (Wikipedia table).'
      ghs:
        - H360
        - H370
        - H372
        - H411
      source: pubchem-manganese
      where: Safety and Hazards, GHS Classification
    - text: 'PubChem aggregated GHS for elemental iron: H319 (causes serious eye irritation) and H335 (may cause respiratory irritation), each in 100 % of reports. H228 and H251 also appear in some notifications. The record covers the element, not the solid A36 steel.'
      ghs:
        - H319
        - H335
        - H228
        - H251
      source: pubchem-iron
      where: Safety and Hazards, GHS Classification
  failure_risks:
    - mode: Atmospheric rusting of unprotected steel
      trigger: Moisture and oxygen at the surface, outdoors or in damp conditions, with no paint or galvanizing
      consequence: Wikipedia says oxidation compromises the structural integrity of a building and endangers occupants and neighbors
      severity: moderate
      source: wiki-structural
      where: Paragraph on exposure and protection
    - mode: Galvanic corrosion when coupled to a more noble metal
      trigger: Electrical contact with copper or tin in a wet electrolyte
      consequence: Steel becomes the anode and corrodes faster at the joint; a broken tin coating on steel is attacked at once
      severity: moderate
      source: wiki-galvanic
      where: Mechanism paragraph; tin can example
    - mode: Strength loss above 650 °F (343 °C)
      trigger: Sustained exposure above 650 °F (343 °C)
      consequence: Minimum ultimate strength of bars and shapes falls to 54 ksi (370 MPa) at 700 °F (371 °C) and to 37 ksi (260 MPa) at 800 °F (427 °C)
      severity: high
      source: wiki-a36
      where: Properties section, sentence on bars and shapes above 650 °F
    - mode: Loss of strength in fire
      trigger: Fire exposure of unprotected steel
      consequence: Wikipedia gives the critical temperature for steel members as about 530 to 810 °C in China, Europe and North America, set by the accepted fire-test standard
      severity: high
      source: wiki-structural
      where: Fire resistance paragraph
  side_effects: []
  handling:
    - text: A36 is readily welded by all welding processes, including shielded metal arc, gas metal arc and oxyacetylene welding (Wikipedia).
      source: wiki-a36
      where: Methods of joining
    - text: 'Protect the steel from moisture: paint or galvanize it before outdoor service, because uncoated steel in contact with water will oxidize (Wikipedia).'
      source: wiki-structural
      where: Paragraph on exposure and protection
    - text: Keep copper and tin out of wet electrical contact with the steel, or stop the electrolyte path at the joint.
      source: wiki-galvanic
      where: Mitigation paragraph
    - text: The PubChem records cover elemental manganese and iron only. Check the supplier safety data sheet before cutting or welding; no A36 safety data sheet was fetched for this profile.
      source: pubchem-iron
      where: Safety and Hazards, GHS Classification (elemental records only)
  mitigations:
    - text: 'Galvanize the steel: zinc protects the steel base metal by sacrificial anodic action (Wikipedia).'
      source: wiki-galvanic
      where: Mitigation paragraph
    - text: Paint or apply an impermeable coating to keep the electrolyte away; where only one metal can be coated, coat the more noble one (Wikipedia).
      source: wiki-galvanic
      where: Mitigation paragraph
    - text: Specify weathering steel for exposed work if a stable rust layer is wanted; it is a different grade from A36 (Wikipedia).
      source: wiki-weathering
      where: Lead paragraph
uses:
  - application: structures
    device: General construction and structural framing
    example: SSAB describes A36 as the steel for general construction and structural applications.
    source: ssab-a36
    where: General Product Description
  - application: structures
    device: Girders, structural shapes and angle iron
    example: A36 is produced as plates, structural shapes, bars, girders, angle iron and T iron.
    source: wiki-a36
    where: Fabricated forms
  - application: structures
    device: Bolted and welded structural joints
    example: A36 is readily welded by all welding processes and is also commonly bolted and riveted in structural applications.
    source: wiki-a36
    where: Methods of joining
supply:
  - subject: Raw steel production by country (2025 estimate)
    abundance: World raw steel 1,900 million t in 2025 (estimated, rounded); United States 82 million t in 2025 (estimated)
    producers:
      - country: China
        share_percent: 51.6
        year: 2025
        basis: 980 of 1,900 Mt raw steel (2025e), computed
      - country: India
        share_percent: 8.4
        year: 2025
        basis: 160 of 1,900 Mt raw steel (2025e), computed
      - country: United States
        share_percent: 4.3
        year: 2025
        basis: 82 of 1,900 Mt raw steel (2025e), computed
      - country: Japan
        share_percent: 4.3
        year: 2025
        basis: 81 of 1,900 Mt raw steel (2025e), computed
      - country: Russia
        share_percent: 3.4
        year: 2025
        basis: 65 of 1,900 Mt raw steel (2025e), computed
    critical_lists: []
    recycling: Not checked (USGS Iron and Steel Scrap chapter, not fetched)
    substitutes: []
    source: usgs-iron-steel
    where: World Production table, raw steel 2025e column
  - subject: US steel mill product imports and import reliance
    abundance: 'US net import reliance 13 % of apparent consumption in 2025 (estimated); total steel mill product imports 24 million t in 2025 (estimated). Import sources 2021 to 2024: Canada 23 %, Mexico 15 %, Brazil 13 %, Republic of Korea 9 %, other 40 %.'
    producers: []
    critical_lists: []
    recycling: ''
    substitutes: []
    source: usgs-iron-steel
    where: Salient Statistics (net import reliance; imports total); Import Sources (2021 to 2024)
  - subject: US end uses, tariffs and substitutes
    abundance: Construction took an estimated 31 % of 2025 net shipments, service centers and distributors 26 %, and automotive 15 %. Tariffs on steel imports rose to 50 % for all countries in June 2025. The normal trade relations duty is free for structural shapes (HTS 7216.00.0000) and hot-rolled bars and rods (7213.00.0000).
    producers: []
    critical_lists: []
    recycling: ''
    substitutes:
      - Iron and steel compete with aluminum and plastics in automotive, and with aluminum, concrete and wood in construction (USGS)
    source: usgs-iron-steel
    where: Domestic Production and Use; Events, Trends, and Issues; Tariff table; Substitutes
  - subject: Critical-mineral status
    abundance: The USGS Iron and Steel chapter (2026) names no critical-minerals list. Iron ore and steel scrap are covered by other USGS chapters that were not fetched.
    producers: []
    critical_lists: []
    recycling: ''
    substitutes: []
    source: usgs-iron-steel
    where: Whole chapter read; no critical-minerals list found
media: []
documents:
  - title: 'USGS Mineral Commodity Summaries 2026: Iron and Steel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-steel.pdf
    year: 2026
  - title: 'SSAB: ASTM A36 structural steel product page (mechanical properties)'
    type: datasheet
    url: https://www.ssab.com/en-us/brands-and-products/commercial-steel/structural-steel/astm-a36
    year: 2026
  - title: 'PubChem: Manganese (CID 23930), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON?heading=GHS+Classification
    year: 2026
  - title: 'PubChem: Iron (CID 23925), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23925/JSON?heading=GHS+Classification
    year: 2026
gaps:
  - The ASTM A36/A36M standard text was not reached (astm.org blocked to the fetch). The minimum yield and tensile values come from the SSAB datasheet and from Wikipedia, which cites the Steel Construction Manual, not from the standard itself.
  - Thermal conductivity for A36 was not found in a readable source. MakeItFrom returned a JavaScript cookie challenge and BeamDimensions a bot challenge in this run. The Engineering ToolBox thermal conductivity rows are for carbon steel at 0.5 %, 1 % and 1.5 % C (54, 43 and 36 W/m K at 20 °C), outside the A36 composition, so none is recorded.
  - A36-specific specific heat, coefficient of thermal expansion and melting range were not found in a readable source. Generic carbon steel rows exist but are not recorded here because they are not A36 values.
  - EN 10025 S235JR (1.0038), S275JR (1.0044), DIN St 37-2 and JIS SS 400 are not recorded as A36 designations. The Arvedi Group EN 10025-2 cross-reference table prints them for S235JR and S275JR only, and no readable source states that A36 is comparable to them. A worldwide equivalents guide found in search was not read.
  - Hot rolling as the mill route is not confirmed in the fetched pages. SSAB lists mill plate and temper-leveled plate; Wikipedia lists plates, shapes, bars and girders.
  - Atmospheric corrosion rate for A36 in micrometres per year was not reached. The ISO 9223 table at PMC returned a 403 block, and the MDPI 2024 atmospheric paper returned an HTML stub.
  - No A36 safety data sheet was read. The hazard entries are PubChem records for elemental manganese and iron, not the solid alloy.
  - Copper is listed as a maximum (0.20 %) in the Wikipedia table. The standard's copper requirement for copper-bearing grades was not read.
  - 'Plate chemistry: the Wikipedia table is for shapes. The plate limits in ASTM A36 were not read from the standard.'
  - 'Critical-mineral lists: the USGS Iron and Steel chapter names none. The EU critical raw materials list was not read. Iron ore and steel scrap recycling are in other USGS chapters that were not read.'
  - Fatigue, hardness, Charpy toughness and low-temperature properties were not sourced.
  - The 32 ksi (220 MPa) yield for plate over 8 in thick comes from Wikipedia only, not from SSAB, which lists thicknesses up to 6.00 in.
sources:
  ssab-a36:
    title: 'SSAB: ASTM A36 structural steel product page'
    id: ASTM A36 (SSAB)
    url: https://www.ssab.com/en-us/brands-and-products/commercial-steel/structural-steel/astm-a36
    kind: datasheet
    year: 2026
    license: SSAB website (cited, not reproduced)
  wiki-a36:
    title: 'Wikipedia: A36 steel'
    id: A36 steel
    url: https://en.wikipedia.org/wiki/A36_steel
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  wiki-structural:
    title: 'Wikipedia: Structural steel'
    id: Structural steel
    url: https://en.wikipedia.org/wiki/Structural_steel
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  wiki-weathering:
    title: 'Wikipedia: Weathering steel'
    id: Weathering steel
    url: https://en.wikipedia.org/wiki/Weathering_steel
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  wiki-galvanic:
    title: 'Wikipedia: Galvanic corrosion'
    id: Galvanic corrosion
    url: https://en.wikipedia.org/wiki/Galvanic_corrosion
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  usgs-iron-steel:
    title: 'USGS Mineral Commodity Summaries 2026: Iron and Steel'
    id: mcs2026-iron-steel
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-steel.pdf
    kind: report
    year: 2026
    license: public domain
  pubchem-manganese:
    title: 'PubChem: Manganese (CID 23930), GHS classification'
    id: CID 23930
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON?heading=GHS+Classification
    kind: database
    license: PubChem terms (public)
  pubchem-iron:
    title: 'PubChem: Iron (CID 23925), GHS classification'
    id: CID 23925
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23925/JSON?heading=GHS+Classification
    kind: database
    license: PubChem terms (public)
license: CC-BY-4.0
updated: '2026-10-24'
review:
  status: draft
  method: assistant
  checked_values: 17
  unreachable: 4
  caveats: 7
  note: 'Written by an AI assistant on 2026-10-24 from pages fetched in this run: SSAB ASTM A36 page, Wikipedia (A36 steel, Structural steel, Weathering steel, Galvanic corrosion), USGS MCS 2026 Iron and Steel, and PubChem GHS for manganese and iron. Not reached: ASTM A36 standard text, MakeItFrom, MatWeb, the PMC ISO 9223 table, and the MDPI 2024 paper. Second deepen pass, 2026-10-24: added the UNS K02600 (Wikipedia) and ASTM A36 (SSAB) designations; generic carbon steel rows for specific heat, expansion and melting range were found and left out because they are not A36 values. Not reached in this run: MakeItFrom and BeamDimensions (bot challenges), the MSU thesis (access denied).'
story:
  recipe:
    line: ASTM A36 (UNS K02600) is a low-carbon structural steel. Wikipedia gives its chemistry for shapes as 0.26 % carbon, 0.40 % silicon, 1.03 % manganese, 0.04 % phosphorus and 0.05 % sulfur maximum, with 0.20 % copper listed as a maximum and iron as the balance. Plate, bars, shapes and girders are made to this grade. The mill rolling route was not confirmed in the fetched pages.
    parts:
      - name: Iron
        symbol: Fe
        share_note: balance (the Wikipedia table lists 98.0 %)
        role: The matrix of the steel, which makes up nearly all of it.
      - name: Carbon
        symbol: C
        share_percent: 0
        share_high: 0.26
        limit: maximum
        role: Main strengthening element, held to a low maximum so the steel stays readily weldable.
      - name: Silicon
        symbol: Si
        share_percent: 0
        share_high: 0.4
        limit: maximum
        role: Deoxidiser in the melt. Flanges over 3 in need a higher range (see identity).
      - name: Manganese
        symbol: Mn
        share_percent: 0
        share_high: 1.03
        limit: maximum
        role: Adds strength. Flanges over 3 in need 0.85 to 1.35 % (see identity).
      - name: Phosphorus
        symbol: P
        share_percent: 0
        share_high: 0.04
        limit: maximum
        role: Impurity held low.
      - name: Sulfur
        symbol: S
        share_percent: 0
        share_high: 0.05
        limit: maximum
        role: Impurity held low.
      - name: Copper
        symbol: Cu
        share_percent: 0
        share_high: 0.2
        limit: maximum
        role: Listed as a maximum in the Wikipedia table. The copper requirement for copper-bearing grades was not checked here.
  risk_groups:
    - title: For people
      level: 0
      verdict: No A36 safety data sheet read
      lead: The hazard records here are PubChem entries for elemental manganese and iron, not for the solid steel.
      points:
        - label: Manganese
          line: PubChem lists elemental manganese with H360 (may damage fertility or the unborn child), H370 and H372 (damage to organs, the second through repeated exposure), and H411 (toxic to aquatic life).
        - label: Iron
          line: PubChem lists elemental iron with H319 and H335 (eye and respiratory irritation), each in 100 % of reports, and H228 and H251 in some notifications.
        - label: Workshop
          line: Check the supplier safety data sheet before cutting or welding. No A36 safety data sheet was fetched for this profile.
    - title: In the environment
      level: 1
      verdict: Rust is the main outdoor risk
      lead: Plain carbon steel is not rust-resistant, so protection is the design choice.
      points:
        - label: Rust
          line: Structural steel cannot be left exposed without protection, because moisture or water causes oxidation (Wikipedia).
        - label: Galvanic
          line: A steel and copper couple in a marina earth path acts as a battery of about 0.5 V (Wikipedia).
    - title: Heat and fire
      level: 1
      verdict: Strength falls above 650 °F (343 °C)
      lead: Bars and shapes keep their minimum strength up to 650 °F (343 °C), then lose it.
      points:
        - label: Bars and shapes
          line: The minimum ultimate strength falls from 58 ksi (400 MPa) to 54 ksi (370 MPa) at 700 °F and to 37 ksi (260 MPa) at 800 °F (Wikipedia).
        - label: Fire
          line: Wikipedia gives about 530 to 810 °C as the critical temperature for steel members in China, Europe and North America, set by the accepted fire-test standard.
  why: 'A36 is the general-purpose structural carbon steel of the United States (Wikipedia, SSAB). It is readily welded by all processes and it keeps a 36 ksi minimum yield in plate under 8 in thick. Its weak point is that it is plain steel: it rusts outdoors and corrodes first when it touches copper or tin in a wet environment.'
  uses:
    - where: Building and general structural framing
      line: SSAB describes A36 as the steel for general construction and structural applications. Structural steel is one of the most commonly used materials in commercial and industrial building construction (Wikipedia).
    - where: Girders and shapes
      line: A36 is made as plates, structural shapes, bars, girders, angle iron and T iron (Wikipedia).
    - where: Welded and bolted joints
      line: A36 is readily welded by all welding processes and is also commonly bolted and riveted in structural applications (Wikipedia).
  can_do:
    - label: Strength
      benchmark: ultimate_tensile_strength
      line: Tensile strength runs from 58 to 80 ksi (400 to 550 MPa) for plate under 8 in thick (SSAB and Wikipedia).
    - label: Yield
      benchmark: yield_strength
      line: Minimum yield is 36 ksi (250 MPa) for plates, bars and shapes under 8 in, and 32 ksi (220 MPa) for plates over 8 in (Wikipedia).
    - label: Stiffness
      benchmark: elastic_modulus
      line: Young's modulus is 200 GPa (29,000 ksi) and Poisson's ratio is 0.26 (Wikipedia).
    - label: Density
      benchmark: density
      line: Density is 7.8 g/cm3, about 0.28 lb/in3 (Wikipedia).
    - label: Ductility
      benchmark: elongation
      line: Minimum elongation is 21 % in 2 in and 18 % in 8 in (SSAB).
    - label: Weldability
      line: Readily welded by all welding processes, and bolted or riveted for structural joints (Wikipedia).
  compare: A36 is a plain carbon structural steel and a common choice for structural framing in the United States. It is not a stainless grade, so it needs paint or galvanizing for outdoor life (Wikipedia). Its minimum yield of 36 ksi applies to plate under 8 in thick.
  compare_rows:
    - scope: material
      label: Minimum yield strength
      benchmark: yield_strength
    - scope: material
      label: Tensile strength
      benchmark: ultimate_tensile_strength
    - scope: material
      label: Stiffness
      benchmark: elastic_modulus
  handling:
    - Specify the thickness band with the strength. The 36 ksi yield applies to plate and shapes under 8 in thick, and 32 ksi applies above 8 in (Wikipedia).
    - Protect the steel from moisture. Paint or galvanize it before outdoor service (Wikipedia).
    - Check the supplier safety data sheet before cutting or welding. No A36 safety data sheet was read here.
  good_for:
    - Welded and bolted structural framing, girders and shapes in general construction (SSAB, Wikipedia).
    - Parts that can be painted or galvanized and kept out of wet contact with copper or tin.
  watch_out:
    - Bare A36 rusts outdoors. The protective patina of weathering steel is a different grade, not A36 (Wikipedia).
    - 'Galvanic corrosion: the steel corrodes first against copper or tin in a wet electrolyte (Wikipedia).'
    - Strength falls above 650 °F (343 °C), and fire reduces the minimum strength (Wikipedia).
  verdict: A36 is the default plain structural carbon steel. It is easy to weld and bolt, and it has a 36 ksi minimum yield for thin plate and shapes. It is not corrosion resistant, so it must be painted or galvanized, and its minimum strength falls above 650 °F (343 °C). Thermal conductivity, specific heat, expansion and melting range for A36 itself are still open.