Toolchest · Datasheet

Accumath Materials Dataset — Notes

Companion to accumath-materials-dataset.csv (52 materials, 19 columns). Compiled 2026-10-20. Every value in the CSV was taken from a named, opened source; the per-row sources column names the site and page for each row.

Coverage and tally

• 52 materials: 12 pure metals, 8 carbon/alloy steels, 10 stainless steels, 7 copper alloys, 5 nickel alloys, 6 aluminum alloys, 2 titanium grades, 2 cast irons.
• 561 of 624 property cells filled (90%); 63 cells deliberately blank (see Gaps).
• NIST-sourced values: 22 — specific heat and melting point for 11 pure elements (Fe, Cu, Ni, Al, Ti, Cr, Mo, Zn, Pb, W, Mg), all from the NIST Chemistry WebBook.
• All other 539 filled values come from the named published sources in each row (producer datasheets, industry-association tables, ASM-derived public data articles, and spec minimums reproduced in open supplier/producer documents).

Legal basis

Per source family:

• NIST / US government (WebBook, JANAF tables) — public domain. Preferred wherever it exists.
• Producer datasheets and published reference pages (Sandmeyer Steel, Langley Alloys, Austral Wright Metals, Ulbrich, Dura-Bar, Wieland Concast, AZoM data articles, Atlas/ASSDA tables, CDA-derived supplier tables, Engineering ToolBox, and similar open publications) — the values recorded are published facts. Facts are not copyrightable; individual factual values are recorded with the source named in the row. No descriptive or expressive text was copied from any source — numbers and facts only.
• ASTM/ASME spec values (yield/tensile minimums, ranges, hardness caps) — recorded as published values reproduced in open producer/supplier documents, not copied from the standards documents themselves.
• MatWeb — excluded. MatWeb's site terms prohibit reuse/redistribution of its compiled data (a terms-of-use matter). No value in this dataset is sourced to MatWeb; where a MatWeb datasheet was the first place a value was seen, the same published fact was re-anchored to an independent source (producer page, AZoM article, or association table) before inclusion.
• Conversions (e.g., resistivity derived from a published %IACS figure by the standard 17.241 nΩ·m = 100% IACS relation, ksi → MPa) are arithmetic on published facts and are flagged in the row notes wherever used.

What NIST had — and didn't have

Checked, in order:

• NIST Chemistry WebBook — the one genuine yield. JANAF (Chase 1998) Shomate equations for the pure elements gave specific heats, and the liquid-phase Shomate ranges gave melting points, for 11 of 12 pure metals. Tin has no Shomate data on the WebBook (only a CODATA entropy figure); tin's Cp and melting point came from WebElements (NBS-based data) instead.
• NIST Alloy Data (trc.nist.gov/metals_data) — a JavaScript web service covering thermophysical data for unary/binary/ternary metal systems; not readable as page text and not applicable to named commercial alloys. No values taken.
• NIST Cryogenic Materials Properties database — the known URL returns 404; not located in readable form. No values taken.
• NIST physics handbook element tables — spectroscopy data only, no engineering physical properties. Dead end.

Net: NIST publishes essentially no mechanical properties and no alloy physical property sets in openly readable form. The NIST-first rule was applied honestly; the bulk of the dataset is necessarily producer/association published data.

Computed specific heats (method)

WebBook Cp values were computed from the published JANAF Shomate coefficients at 298.15 K (Cp = A + B·t + C·t² + D·t³ + E/t², t = T/1000) and converted from J/mol·K using standard atomic weights. These are NIST's own published fits evaluated at room temperature, not estimates.

Conventions used

• Temperature basis: room temperature (≈20–25 °C) unless the cell or row note says otherwise (several conductivity values are at 100 °C, as published; CTE cells always state their temperature range).
• Condition: annealed / standard condition per family, stated in the row notes (e.g., 17-4 PH is Condition H900, Inconel 718 is solution-annealed-and-aged, cast copper alloys are as-cast, cast irons as-cast, aluminum tempers are in the material name).
• Spec-driven grades (A36, A516 Gr 70, A105, A106 Gr B, most stainless plate grades, ductile iron): the ASTM range or minimum is recorded as published (e.g., "400-550", "250 (min)") rather than a single typical value.
• Hardness always carries its scale (HB, HRB, HRC, HV).

Source conflicts found (loser noted, winner used)

• Chromium melting point: NIST JANAF implies 1857 °C; the modern accepted value is 1907 °C. NIST value recorded (NIST-first rule) with the caveat in the row.
• A105 hardness cap: supplier reproductions of A105 give 187 HBW max; one 2026 guide claims the current standard says 197 HBW. 187 recorded; flag before relying on it for acceptance work.
• Sandmeyer 2205 FAQ prints resistivity "33.5 µΩ·cm" — that is the µΩ·inch figure; not used (Langley Alloys value used). Sandmeyer C-276 page prints resistivity "720 µΩ·cm" — an error; Haynes figure (130 µΩ·cm) used.
• 316 specific heat: Sandmeyer lists 450 J/kg·K; AZoM-consistent sources list 500. 500 recorded.
• 304 density/CTE: Sandmeyer (producer) lists 7900 kg/m³ and 16.6e-6/K (20–100 °C); the Atlas/ASSDA table lists 8000 and 17.2e-6/K (0–100 °C). Each row uses one coherent set: 304 = Sandmeyer, 304L = Atlas.
• C83600 modulus: AZoM prints 83 GPa; CDA data (Wieland Concast) gives 93.1 GPa. CDA figure used.
• C46400 thermal conductivity: CDA publications list 116 W/m·K; MakeItFrom's ASM-derived value is 120. 120 recorded.
• C71500 resistivity: CDA-derived tables give 340 nΩ·m; two supplier datasheets give 350–380. 340 recorded.
• 254 SMO density: one supplier table lists 8240 kg/m³; AZoM/Outokumpu-consistent value is 8000. 8000 recorded.
• A36 resistivity: Wikipedia gives 142 nΩ·m at 20 °C; metalzenith gives 162. 142 recorded.
• 7075 specific heat: one supplier page lists 796 J/kg·K — an outlier against ASM/Chalco 960. 960 recorded.
• Titanium Grade 2 resistivity: producer datasheet gives 530 nΩ·m; one supplier page gives 420 (the pure-Ti figure). 530 recorded.
• 1018 CTE/resistivity: recorded from ASM tables (annealed basis) rather than the cold-drawn datasheet, which does not publish them.

Gaps (deliberately blank — never estimated)

• Poisson's ratio (14 blanks): Cr, Zn, Mg (pure metals); 304, 316, 316L, 317L, 410, 2507 (stainless); C83600; Inconel 718; Incoloy 825; 6061-T6; A516 Gr 70. Published values exist behind compilation paywalls or were not found on an opened page this pass. This is the dataset's single biggest gap class.
• Pure-metal mechanicals: yield/tensile/elongation/hardness left blank for most pure metals — for pure elements these swing wildly with purity and cold work, and publishing a single number would mislead. (Exceptions where a producer publishes an annealed typical: Fe, Cu, Al.)
• A516 Gr 70: elastic modulus, Poisson, and resistivity blank — no grade-specific values on an opened source (generic carbon-steel figures were not transferred across grades).
• A105 / A106 Gr B resistivity: blank (published figures found were internally inconsistent template data and were rejected).
• Gray iron Class 40: yield blank (gray iron has no well-defined yield point); resistivity blank (published figures conflict by ~3×).
• C46400 annealed hardness: blank; only other-temper values were found.
• UNS numbers: left blank for the 12 pure elements (no UNS in common use).

Caveats

• Mechanical properties vary with product form, thickness, and heat/lot. Values here are reference values for the stated condition, not design allowables and not a substitute for the governing specification or an MTR.
• Several supplier pages reproduce the same underlying ASM/CDA/producer tables; where two "sources" agree, they may not be fully independent. Producer pages were treated as authoritative where sources conflicted.
• Melting ranges for steels from solidus/liquidus tabulations (MakeItFrom, ASM-derived) run lower than the generic "1425–1540 °C" ranges printed on many supplier pages; the solidus/liquidus figures were preferred for consistency across the steel rows.