# AFN materials intelligence Honest, cited material knowledge for agents. When a buyer says *"my PLA part broke, what's stronger?"* or *"will this survive outdoors?"*, this pack lets an agent answer from published fact instead of memory — furnishing metals and meaningfully-stronger 3D-printing materials per spec, plus finishes, coatings, and inspection options, with the vendor-admitted caveats **first**. It is exposed three ways, all from one source of truth (`packages/core/src/material-knowledge.ts`): - the **`get_material_guide`** MCP tool (reaches ChatGPT, Claude, Gemini, and make-this.ai — the tool list is forwarded verbatim, so every agent gets the same facts); - the **`ufp://materials/guide.md`** MCP resource (the whole pack as one digest); - this human-readable page at **`/docs/materials.md`**. ## The rules (why this file can be trusted) 1. **Caveats first, never buried.** Standard SLA resin embrittles under UV — that leads the resin section, before any strength boast. Bare carbon steel rusts — that leads the steel entry. 2. **A spec number only ever appears with a source, and every source is tagged.** `[vendor: , cited ]` means a vendor published it (verbatim where short); `[general]` means widely-published engineering knowledge, phrased as *typical/approximate* and never dressed up as a vendor's number. Nothing is invented. 3. **Facts, not fitness.** This pack gives comparative facts and vendor specs. It never asserts that a material is *safe* or *fit* for a buyer's specific application — that decision stays with the buyer, and the agent acts only on **express vendor claims** (called "advertised"/"listed", never "certified" unless the vendor's own words say so). See [Safety](#safety). --- ## The "stronger / hotter / more weatherproof than X" ladders Each ladder runs weakest → strongest; materials in the same bracket are roughly equivalent. The point is the walk from a failed plastic part up into tougher plastics and then metals. ### Toughness — the "won't snap" ladder `[general]` > PLA → PETG → ABS / ASA → nylon / PC → PA12-CF → PEEK → aluminum (5052 / 6061 / > 7075) → stainless / carbon steel → titanium (Ti-6Al-4V) **Read this axis carefully:** it ranks *real-world durability / impact toughness* ("won't snap"), **not** tensile-strength-at-break. PLA's published tensile number is actually high — it sits at the bottom because it is **brittle**, which is what "broke" almost always means. Within the metals the exact order depends on alloy and temper (7075 aluminum at 440–540 MPa overlaps steel; titanium wins on strength-*to-weight*, steel on absolute strength). ### Heat resistance — by heat-deflection temperature `[general, with cited HDTs]` > PLA → PETG → standard resin → ABS / ASA → nylon / PC → PA12-CF / high-temp > resin → PEEK → metals Resin grades span the widest range (standard ~55 °C up to a high-temp grade's 230 °C), so a high-temp resin can outrank several FDM plastics — match the specific grade's cited HDT to the service temperature. ### Outdoor / UV & weather durability `[general, with cited outdoor claims]` > standard resin → PLA → ABS → PETG / nylon / PC → **ASA** → aluminum / > galvanized steel → stainless / titanium Ranks resistance to sun/UV and weather, **not** strength. Standard SLA resin and PLA degrade fastest (vendor-admitted for resin); **ASA** is the made-for-outdoors plastic (vendor-cited); metals — especially stainless, galvanized, and anodized/powder-coated aluminum — weather best. Bare carbon steel is the exception: strong, but it rusts. --- ## Materials (caveats first) ### FDM plastics **PLA** — the default, cheapest, easiest filament: dimensionally accurate and stiff, but the least durable common choice. - ⚠ Brittle — snaps rather than bends; a high tensile number that fails without warning. `[general]` - ⚠ Softens around 55–60 °C — deforms in a hot car or dishwasher. `[general]` - ⚠ Not weather-durable; UV and moisture embrittle it outdoors. `[general]` - Heat-deflection temp ~55 °C. `[general]` · No vendor advertises any PLA capability — Slant3D and JLC list it bare. `[vendor: slant3d, cited 2026-07-14]` **PETG** — the pragmatic step up: tougher, more ductile, better chemical and moisture resistance. The common "my PLA snapped" answer. - ⚠ Still softens ~70–80 °C. `[general]` - ⚠ Only moderate UV stability — not made-for-outdoors like ASA. `[general]` - ⚠ No vendor on the fleet advertises PETG as outdoor/submersible/heat-rated. `[vendor: slant3d, cited 2026-07-14]` **ABS** — impact-tough styrenic, better heat tolerance (~95 °C); the classic enclosure plastic. - ⚠ Poor UV stability — yellows and chalks outdoors; use ASA for sun. `[general]` - ⚠ Warps, needs an enclosed printer, emits fumes. `[general]` - Heat-deflection temp ~95 °C. `[general]` **ASA** — ABS's UV-stable sibling: same toughness and ~95–100 °C, but made to survive sun and weather. - ⚠ "Outdoor-rated" means the vendor advertises UV/weather resistance for the *material* — not a guarantee your *part* survives a given environment. `[general]` - Outdoor / UV: advertised UV-resistant `[vendor: slant3d, cited 2026-07-14]` · Heat-deflection temp 97.8 °C `[vendor: jlc3d, cited 2026-07-28: "Suitable for using outdoors, sunlight and UV light environments. Heat deflection temp: 97.8℃"]` **Nylon (PA12 / PA6 / PA11)** — tough, abrasion-resistant, semi-flexible; great for living hinges, gears, snap-fits. (Also printed via SLS/MJF powder, which AFN has no process module for.) - ⚠ Hygroscopic — absorbs moisture, changing dimensions and properties. `[general]` - ⚠ Harder to print; narrower availability. `[general]` - MJF PA12-HP heatproof 175 °C `[vendor: jlc3d, cited 2026-07-28]` **PA12-CF (carbon-fiber nylon)** — stiffer and more heat-resistant than plain nylon, approaching metal-like rigidity for lightweight brackets. - ⚠ The fill adds stiffness/heat resistance but *reduces* nylon's impact ductility — stiffer, not tougher-in-impact. `[general]` - ⚠ Abrasive to print, pricier, fewer vendors. `[general]` - Heat-deflection temp 105 °C `[vendor: jlc3d, cited 2026-07-28]` **Polycarbonate (PC)** — high-impact, high-heat (~110–130 °C); takes a hit and some heat while staying a plastic. *(Not yet in the family matcher.)* - ⚠ Demanding to print; moisture-sensitive; narrower availability. `[general]` - ⚠ Unfilled PC yellows under prolonged UV unless UV-stabilized. `[general]` **TPU (flexible)** — rubber-like: gaskets, bumpers, grips. *(Not yet in the family matcher.)* - ⚠ Not a structural material — chosen for flexibility, not stiffness; "strength" is the wrong axis. `[general]` **PEEK** — top of the polymer ladder: high strength, high heat, chemical resistance, UL94 V0. *(Not yet in the family matcher.)* - ⚠ Expensive and demanding (very-high-temp printer); niche, low availability. `[general]` - Temperature / flammability: high-temp, UL94 V0 `[vendor: jlc3d, cited 2026-07-28: "High-temperature resistance, high strength & stiffness, excellent chemically resistant, biocompatibility, flammability resistant UL94 V0"]` ### SLA resins **Standard SLA resin** — unbeatable fine detail and smooth surface; the trade-off is durability. - ⚠ **Embrittles and degrades under UV / strong sunlight** — self-admitted; a display/detail material, not outdoor or structural. `[vendor: jlc3d, cited 2026-07-28: "Black Resin: Not suitable for high temperature and strong sunlight environment. Heatproof: 58℃"]` - ⚠ Low heat tolerance — common resins deflect ~53–59 °C. `[vendor: jlc3d, cited 2026-07-28: "8228 Resin … Heatproof: 56.4℃"]` - ⚠ Brittle — thin walls and fine features snap. `[general]` - 9600 (default) heatproof 59 °C; 8001 clear HDT 53 °C `[vendor: jlc3d, cited 2026-07-28]` **Tough / durable resin** — trades some brittleness for impact resistance. - ⚠ Still a resin — generally below FDM nylon/PC for sustained load, and below all of them for heat unless it is a high-temp grade. `[general]` - ⚠ "Water resistance" on some tough resins is not a submersion claim. `[vendor: proto3000, cited 2026-07-18]` **High-temp resin** — SLA's fine detail on a part that also sees heat; HDTs ~100 °C to 230 °C by grade. - ⚠ Often still brittle — buys heat tolerance, not toughness. `[general]` - JLC Temp HDT 101 °C · Rigid 10K 82 °C @1.8 MPa · Flame Retardant 111 °C @0.45 MPa · ULTEM 9085 (FDM) HDT 153 °C `[vendor: jlc3d / proto3000, cited 2026-07-18–28]` · Ultra High-temp 230 °C @0.45 MPa `[vendor: makerverse, cited 2026-07-24]` **High-detail resin** — the finest features (miniatures, jewelry masters). - ⚠ The most brittle end of resin — a display/master material; standard resin's UV and heat caveats apply in full. `[vendor: jlc3d, cited 2026-07-28]` ### Metals (CNC, sheet & metal AM) **Aluminum 6061** — the default general-purpose CNC aluminum: strong, light, corrosion-resistant, readily anodized. - ⚠ Not as strong as 7075 or steel — trades peak strength for machinability, weldability, and corrosion resistance. `[general]` - Tensile ~290–310 MPa (T6); good corrosion, readily anodized. `[general]` **Aluminum 7075** — aerospace-grade: markedly stronger than 6061 (approaching steel), still aluminum-light. - ⚠ Lower corrosion resistance and poor weldability vs 6061 — a strength alloy, not a marine/weld one. `[general]` - Tensile 440–540 N/mm² (MPa) `[vendor: spanflug, cited 2026-07-18]` **Aluminum 5052** — the go-to sheet-metal aluminum: excellent corrosion resistance (marine), good weldability and formability. - ⚠ A formable sheet alloy, not a high-strength billet — use 6061/7075 for machined strength. `[general]` - Tensile 170–305 MPa; yield > 90 MPa; excellent corrosion resistance, good weldability & formability `[vendor: jlc3d, cited 2026-07-28: "non-heat-treatable Al-Mg alloy … Tensile 170-305 MPa, Yield > 90 MPa"]` **Stainless steel 304** — the workhorse stainless: strong, stiff, corrosion-resistant, common in food/wet use. - ⚠ Heavy and harder to machine/cut than aluminum. `[general]` - ⚠ "Regularly used in food applications" is a fact about the *alloy*, **not** a food-safety certification of your part — act only on an express vendor food-safe claim, called "advertised", never "certified". `[general]` - ~3× stiffer and ~2× stronger than the same part in 5052 aluminum; tensile ~515 MPa. `[general]` **Stainless steel 316 / 316L** — the marine/chemical stainless: added molybdenum resists salt, acids, and chlorides far better than 304. Also the workhorse metal-AM powder (SLM and binder jet — see the metal 3D printing section). - ⚠ More expensive than 304 and no stronger in plain strength — you pay for corrosion resistance, not load capacity. `[general]` - ⚠ 3D-printed 316L comes out rough as printed — Ra 3.2–12 µm (SLM), Ra 4–8 µm (binder jet) vs near-mirror machined faces; critical sealing/bearing faces typically need post-machining. `[vendor: jlc3d, cited 2026-07-28]` - Exceptionally high corrosion resistance vs acids & chlorides `[vendor: spanflug, cited 2026-07-18]` **Carbon / mild steel (1018, A36, S235, SPCC)** — strong, stiff, cheap, weldable; the structural default when weight is not the constraint. - ⚠ **Rusts** — bare steel corrodes in any moisture; outdoors it needs a coating (powder coat, zinc/galvanizing, paint, black oxide) or switch to stainless/aluminum. (This is why the sheet lane upgrades unpinned mild steel to powder-coat when a part must survive outdoors.) `[general]` - ⚠ Heavy — ~3× aluminum's density. `[general]` - Yield ~250–350 MPa (mild); ~3× aluminum's stiffness. `[general]` **Galvanized steel** — carbon steel with a sacrificial zinc coating: steel's strength and low cost with built-in outdoor corrosion protection. - ⚠ Cut/weld edges lose the zinc and can still corrode; galvanizing fumes are a welding hazard. `[general]` **Titanium Ti-6Al-4V (Grade 5)** — top of the common-metals ladder for strength-to-weight; excellent corrosion resistance and biocompatibility. Printable (SLM) — which is how complex titanium geometry usually gets made. - ⚠ Expensive and hard to machine — steel is stronger in absolute terms and far cheaper; specify titanium only when strength-to-weight or corrosion/biocompat genuinely justify it. `[general]` - ⚠ Printed (SLM) titanium is the priciest lane on the network; fatigue-critical printed Ti is typically heat-treated or HIP'd and post-machined on critical faces. `[general]` - Excellent corrosion resistance, high specific strength `[vendor: jlc3d, cited 2026-07-28]`; tensile ~900–950 MPa `[general]` ### Metal 3D printing (SLM / binder jet) — `metal_print` A first-class lane since 2026-07-30 (JLC3DP: SLM 316L / Titanium TC4 / binder-jet 316L; PCBWay: SLM 316L / AlSi10Mg / Titanium TC4 / tool steel). It fans on every STL/STEP drop as its own lane, alongside the plastic ones — expect its offers 10–100× the plastic prices on the same part (that's the physics, stated on each offer). Asking by name ("metal 3D printing", "SLM", "printed titanium") prunes the quote to metal-capable vendors. Cross-cutting AM caveats `[general]`, before any per-alloy boast: - ⚠ As-printed surfaces are rough (see per-alloy Ra where published) with support-contact witness marks on down-facing faces — critical faces are typically post-machined. - ⚠ Printed metal is mildly anisotropic (build direction); fatigue-critical parts are typically stress-relieved, heat-treated, or HIP'd — ask the vendor which condition they ship. **Aluminum AlSi10Mg (metal AM)** — the standard LPBF aluminum; light, thermally conductive, prints complex heat-exchanging geometry. - ⚠ NOT 6061 — a casting alloy: lower elongation/toughness than wrought 6061-T6; if the part is machinable, machined 6061 is usually cheaper and tougher. `[general]` - Tensile ~330–430 MPa as-built (typical LPBF); ~2.67 g/cm³. `[general]` **Tool steel (metal AM)** — hard, wear-resistant prints for mold inserts and dies; conformal cooling channels machining cannot make. - ⚠ About hardness/wear, not general structure — 316L or mild steel is far cheaper for an ordinary strong part; heat treatment sets final hardness (~45–52 HRC typical H13-class). `[general]` **Brass (C360 / H59)** — free-machining copper-zinc alloy: excellent machinability, decorative gold finish, good corrosion resistance. - ⚠ Chosen for machinability and looks — not a high-strength structural metal. `[general]` - The most machinable common metal `[vendor: spanflug, cited 2026-07-18]` **Copper (C110 / T2)** — chosen for electrical and thermal conductivity. - ⚠ Soft, gummy to machine, work-hardens; a conductivity material, not a structural one. `[general]` > **PCBWay:** its per-material research is still running > (`packages/adapters/pcbway`). PCBWay-specific published numbers are > intentionally **omitted here rather than guessed** — the coordinator fills the > `PCBWAY_TODO` stub after the scrape lands. PCBWay already quotes generic > materials in this pack (e.g. PLA, Aluminum 5052), so those entries already > serve a PCBWay user. --- ## Finishes, coatings & inspection glossary **Finishes & coatings** - **Anodizing** (aluminum, titanium) — electrochemical oxide layer; corrosion resistance + color. Hardcoat variant adds wear resistance. Conductive variant keeps surface conductivity. - **Powder coating** (steel, aluminum) — baked-on colored polymer coat; durable weather/corrosion protection; the common outdoor upgrade for bare steel. - **Passivation** (stainless, brass, titanium) — restores the corrosion-resistant oxide layer; removes free iron. - **Bead blasting** — uniform matte texture; preps for coating. - **Brushing** — directional satin grain. - **Blackening (black oxide)** (carbon steel) — mild corrosion resistance + matte black look. - **Galvanizing / zinc plating** (steel) — sacrificial zinc corrosion protection. - **Electropolishing** (stainless) — smooths, brightens, improves corrosion resistance; common for food/medical. - **Vapor smoothing** (ABS) / **vapor polishing** (PC, acrylic) — solvent/vapor gloss; seals layers or restores clarity. - **Sanding / spray painting / oil spraying** (3D prints) — smooth layer lines, add color, restore transparency on clear resin. - **Dyeing** (SLS/MJF nylon), **deburring** (machined/sheet), **laser marking** (metals), **mirror polishing** (brass, stainless). **Inspection & QA** - **ISO 2768** — general-tolerance standard (fine/medium/coarse) for dimensions not explicitly toleranced on a drawing. - **First Article Inspection (FAI)** — a measured report proving every drawing dimension before a batch runs. - **CMM** — coordinate-measuring machine; precise dimensional verification. - **Material certificate (mill cert, EN 10204 3.1)** — traceable alloy composition/heat lot; request when traceability matters. - **Surface roughness (Ra)** — average roughness in µm; quantifies smoothness. - **UL94** — flammability rating (V0 best); a *material* claim, not a part safety guarantee. --- ## Safety These are comparative **facts** and vendor-published specs (caveats first), not a fitness-for-purpose or safety judgment for any application. An agent using this pack relays the facts, acts only on express vendor claims — calling them "advertised"/"listed", never "certified" unless the vendor's own words say so — and leaves the final call to the user. No food-safety judgments, no structural or medical adequacy calls, no "strong enough to hold your X". The pack supplies what to compare; the decision is the buyer's. --- *Source of truth: `packages/core/src/material-knowledge.ts`. This page and the `ufp://materials/guide.md` MCP resource are renderings of that data; if they ever disagree, the code wins.*