Aerospace sheet metal fabrication refers to the controlled forming, cutting, joining, and finishing of metallic sheet stock — typically 0.3 mm to 6.35 mm (0.012″ to 0.250″) gauge — into structural and secondary flight components that meet the tight dimensional, material, and traceability requirements mandated by aviation regulatory bodies and OEM quality systems.
Unlike general-purpose sheet metal work, aerospace fabrication is governed by a hierarchy of standards: aircraft manufacturers publish their own process specifications (e.g., Boeing BPS, Airbus AIMS), while industry standards such as AMS 2750 (pyrometry), AMS-QQ-A-250 (aluminium sheet properties), MIL-HDBK-5J / MMPDS (metallic materials properties), and quality management system standard AS9100 Rev D define acceptable materials, processes, and inspection criteria. Surface treatments follow MIL-A-8625 (anodising) and MIL-DTL-5541 (chemical conversion coating), ensuring corrosion protection without introducing hydrogen embrittlement in high-strength alloys.
Common aerospace sheet metal assemblies include fuselage skin panels, wing ribs and stringers, floor-beam webs, engine nacelle frames, avionics equipment racks, and access-door skins. Each part requires a documented material certificate (EN 10204 3.1 minimum, or 3.2 for safety-critical items), a first-article inspection (FAI) report, and, where applicable, non-destructive testing (NDT) results.
Material selection in aerospace sheet metal fabrication is driven by specific strength-to-weight ratio, fatigue life, corrosion resistance, and compatibility with joining processes. The table below summarises the alloy families processed at Jiafeng alongside their governing specifications and primary applications.
| Material / Alloy | Governing Spec | Tensile Strength (UTS) | Density | Typical Thickness Range | Key Application |
|---|---|---|---|---|---|
| Aluminium 2024-T3 | AMS-QQ-A-250/4 | 448 MPa | 2.78 g/cm³ | 0.4 – 6.35 mm | Fuselage skins, wing lower surfaces |
| Aluminium 7075-T6 | AMS-QQ-A-250/12 | 572 MPa | 2.81 g/cm³ | 0.5 – 6.35 mm | Wing spars, ribs, structural frames |
| Aluminium 5052-H32 | AMS-QQ-A-250/8 | 228 MPa | 2.68 g/cm³ | 0.5 – 4.0 mm | Fuel tanks, hydraulic panels, fairings |
| Titanium Grade 2 (CP) | AMS 4902 | 345 MPa | 4.51 g/cm³ | 0.5 – 4.0 mm | Firewalls, hydraulic tubing supports |
| Titanium Ti-6Al-4V (Gr 5) | AMS 4928 AMS 4911 | 950 MPa | 4.43 g/cm³ | 0.5 – 3.2 mm | Engine pylons, thrust reversers, brackets |
| Stainless Steel 321 | AMS 5510 | 515 MPa | 7.90 g/cm³ | 0.5 – 3.0 mm | Exhaust ducts, hot-zone shrouds |
| Stainless Steel 347 | AMS 5512 | 655 MPa | 7.96 g/cm³ | 0.5 – 3.0 mm | High-temperature exhaust manifolds |
| Inconel 625 | AMS 5599 | 827 MPa | 8.44 g/cm³ | 0.3 – 2.5 mm | Combustion liners, turbine shrouds |
Source references: MMPDS-12 (Metallic Materials Properties Development and Standardization), AMS specifications via SAE International, ASM Handbook Vol. 2 (Properties and Selection: Nonferrous Alloys and Special-Purpose Materials), and MIL-HDBK-5J.
Jiafeng operates a vertically integrated sheet metal manufacturing workflow. For aerospace work, every process step is documented, traceable, and subject to first-piece and in-process inspection. Our equipment capabilities are detailed on the Sheet Metal Manufacturing page.
3 kW – 12 kW fibre lasers cut aluminium, titanium, and stainless sheet to ±0.05 mm positional accuracy with HAZ depths below 0.1 mm — meeting aerospace edge-quality requirements without secondary deburring in most cases. Nested programming maximises material yield on expensive aerospace alloys.
Salvagnini automatic bending cells and 35 T – 250 T CNC press brakes with back-gauge positioning achieve bend angles held to ±0.3°. For aerospace aluminium (2024, 7075), bend radii are specified per AMS 2770 temper requirements to avoid cracking — a detail Jiafeng engineers review at the DFM stage.
One 5-axis machining centre (φ2 – φ26 mm, ±0.005 mm) and two 4-axis centres enable complex contoured features — lightening holes, joggled flanges, and compound-angle pads — machined in a single setup to eliminate re-fixturing error. Linked to our Precision Machining capabilities.
3 kW laser welding robots and manual TIG welding (for aluminium and titanium) produce low-distortion, narrow-HAZ joints. TIG procedures for titanium use inert gas back-purging to prevent oxidation — colour acceptance per AWS D17.1 (aerospace welding standard). Weld inspections available per EN ISO 17637 (visual) and EN ISO 17640 (UT).
Hard anodising (MIL-A-8625 Type III), chemical film / Alodine (MIL-DTL-5541 Class 1A / 3), passivation (AMS 2700), and zinc-nickel plating to AMS 2417. All treatment lines are documented and subject to periodic bath analysis. Salt spray test results ≥ 96 h per ISO 9227 / ASTM B117.
CMM systems (E = 1.9 + 3L/1000 µm), CCD optical dimension inspection (±50 µm), XRF element analysis (10 – 20 ppm, RSD <10%), and first-article inspection (FAI) per AS9102. Jiafeng supports PPAP Level 3 documentation packages for customers requiring design record, process flow, FMEA, and measurement system analysis.
The table below maps Jiafeng's production equipment to the dimensional tolerances achievable for aerospace sheet metal fabrication, alongside the relevant industry standards for each process step.
| Process | Equipment | Working Range / Capacity | Achievable Tolerance | Applicable Standard |
|---|---|---|---|---|
| Fibre Laser Cutting | 3 kW – 12 kW fibre laser | Up to 20 mm steel; ≤ 10 mm Ti / Al | ±0.05 mm (position); edge roughness Ra ≤ 6.3 µm | ISO 9013 |
| CNC Punching | 1500 × 3000 mm punch press; 45 T – 260 T mechanical press | Sheet up to 3000 × 1500 mm | ±0.1 mm (hole position); ±0.05 mm (hole size) | ISO 2768-m |
| CNC Press Brake Bending | Salvagnini automatic bender; 35 T – 250 T CNC press brake | Up to 3200 mm bend length | ±0.3° bend angle; ±0.15 mm flange length | ISO 2768-m AMS 2770 |
| 5-Axis Machining | 5-axis machining centre | φ2 – φ26 mm | ±0.005 mm (positional) | ISO 10791-7 |
| 4-Axis Machining | 4-axis machining centre (×2) | φ2 – φ20 mm | ±0.008 mm | ISO 10791-7 |
| Laser Welding | 3 kW laser welding robot | Panel up to 1800 × 2300 mm | Weld width ≤ 1.5 mm; distortion < 0.3 mm/m | AWS D17.1 EN ISO 15614-11 |
| TIG Welding (Ti/Al) | Manual TIG stations with back-purge fixtures | Thickness 0.5 – 6 mm | Visual acceptance: Class B per ISO 5817; titanium colour: silver/light gold only per AWS D17.1 | AWS D17.1 ISO 5817 |
| Electroplating (Zinc) | Fully automated zinc plating line | 3000 × 750 × 1500 mm per rack | Coating thickness 8 – 25 µm per zone; uniformity ±2 µm | ISO 4042 AMS 2417 |
| Powder Coating | Immersion pre-treatment + electrostatic spray | Up to 6000 × 1500 × 2980 mm | Film build 60 – 120 µm; adhesion cross-cut Class 0 per ISO 2409 | ISO 12944 |
| CMM Inspection | High-precision CMM (×1) + Standard CMM | Full-part 3D measurement | E = (1.9 + 3L/1000) µm volumetric | ISO 10360-2 AS9102 FAI |
Surface treatment in aerospace sheet metal fabrication is not cosmetic — it is a structural requirement. Incorrect treatments can introduce stress corrosion cracking in 7xxx aluminium, hydrogen embrittlement in high-strength steel, or inter-granular corrosion in sensitised stainless steel. The selection matrix below guides treatment choice by material and service environment.
| Treatment | Spec / Standard | Substrate | Thickness (µm) | Salt Spray (hrs) | Notes / Application |
|---|---|---|---|---|---|
| Hard Anodise (Type III) | MIL-A-8625 Type III | Aluminium alloys | 25 – 75 | >336 | Wear surfaces, hinges, actuator guides; avoid on 2024 near fatigue locations |
| Chemical Film (Alodine) | MIL-DTL-5541 Cl 1A | Aluminium alloys | 0.5 – 2 | 168 | Electrical bonding primer; low hydrogen risk; Class 3 for unpainted electrical contacts |
| Passivation (Citric) | AMS 2700 Type 2 | Stainless steel 300/400 series | Inherent oxide | 96 (min per ASTM A380) | Medical, food, and oxygen-system compatibility; no hydrogen embrittlement risk |
| Zinc-Nickel Plating | AMS 2417 | Carbon/alloy steel, some stainless | 5 – 15 | >500 | Cadmium-free alternative for aerospace fasteners and brackets; bake for HE relief on >1000 MPa steels |
| Electroless Nickel (EN) | AMS 2404 | Steel, aluminium, titanium | 12 – 50 | >200 (6–8% P, low-phosphorus) | EMC shielding, bearing surfaces; uniform deposit on complex geometry |
| Powder Coat + Primer | ISO 12944 | All metals | 60 – 120 | 500 (primer + topcoat system) | Ground-support equipment (GSE), interior structural frames; not for flight-critical wear surfaces |
Reference standards: MIL-A-8625F (Anodic Coatings for Aluminium), MIL-DTL-5541F (Chemical Conversion Coatings on Aluminium), AMS 2700E (Passivation of Corrosion Resistant Steels), AMS 2417G (Plating, Zinc-Nickel Alloy), AMS 2404D (Electroless Nickel Plating).
The following part families are regularly produced through our aerospace sheet metal fabrication workflow. Structural classification follows FAR/CS 25.303 categories used in civil aircraft certification.
| Part Family | Structural Class | Typical Material | Key Process | Critical Requirement |
|---|---|---|---|---|
| Fuselage Skin Panels | Primary — fatigue critical | Al 2024-T3 | Laser cut → CNC bend → riveted assembly | Clad surface intact; Alclad edge protection; crack-growth-tolerant design |
| Wing Ribs & Spars | Primary — strength critical | Al 7075-T6 / 7050-T7451 | Laser cut → 5-axis machine → TIG weld (fittings) | Tight lightening-hole edge tolerances; no re-drilling of primary holes |
| Engine Nacelle Brackets | Secondary — high temperature | Ti-6Al-4V / SS 321 | Laser cut → TIG weld (purged) → hard anodise or passivation | Titanium weld colour acceptance; no oxidation; vibration-fatigue life |
| Avionics Enclosures / Racks | Secondary — EMC critical | Al 5052 / Al 6061 | Laser cut → CNC punch → bend → chemical film (Alodine) | Electrical bonding continuity; flatness ≤ 0.5 mm/m; EMC shielding continuity |
| Floor Beam Webs | Primary — cabin load path | Al 2024-T3 / Al 7075-T6 | Laser cut → joggle bend → chemfilm + primer | Joggle radius compliance per OEM spec; no cold-work damage to fastener holes |
| Access Door Skins | Secondary — aerodynamic | Al 2024-T3 / CFRP-metal hybrid | Laser cut → stretch form → paint system | Surface waviness ≤ 0.8 mm/300 mm; paint adhesion Class 0 per ISO 2409 |
| Exhaust Ducting / Hot Sections | Secondary — high temperature | SS 347 / Inconel 625 | Laser cut → TIG weld → passivation | No sensitisation (stabilised grade); weld micro-inspection; high-temp oxidation resistance |
| Hydraulic Line Brackets | Secondary — system support | Ti Grade 2 / Al 6061 | Laser cut → CNC bend → zinc-nickel plating | Torque-out resistance; MIL-DTL-5541 compatibility with hydraulic fluid (Skydrol) |
Beyond AS9100, aerospace sheet metal fabrication involves adherence to process-specific standards. Heat treatment of aluminium prior to forming follows AMS 2770; welding qualification procedures align with AWS D17.1 / EN ISO 15614; and non-destructive testing (when specified) follows NAS 410 / EN 4179 for personnel certification and ASTM E1444 (magnetic particle) or ASTM E1417 (liquid penetrant) for inspection execution.
| Standard | Issuing Body | Scope | Relevance to Sheet Metal Fabrication |
|---|---|---|---|
| AS9100 Rev D | SAE International / IAQG | Quality management systems — aerospace | Overall QMS framework; risk-based thinking; configuration management; FOD prevention |
| AS9102 | SAE / IAQG | First Article Inspection (FAI) | Dimensional, material, and functional verification of first production part |
| AMS 2770 | SAE International | Heat treatment of aluminium alloys | Temper control before forming; prevents forming-induced over-ageing in 7xxx series |
| AWS D17.1 / D17.2 | American Welding Society | Fusion and resistance welding — aerospace | Weld procedure qualification (WPS), welder certification, acceptance criteria |
| NAS 410 / EN 4179 | AIA / ASD-STAN | NDT personnel qualification | Level I–III certification for PT, MT, UT, ET, RT applied to sheet metal assemblies |
| NADCAP (PRI) | Performance Review Institute | Special processes audit programme | Accreditation for heat treatment, welding, NDT, chemical processing; required by most primes |
| ISO 9227 / ASTM B117 | ISO / ASTM | Salt spray corrosion test | Verification of surface treatment corrosion performance after plating / coating |
| ASTM E1417 | ASTM International | Liquid penetrant testing | Detection of surface-breaking defects in welded aerospace sheet metal assemblies |
