AWS D17.1 Fusion Welding
AWS D17.1 fusion welding for aerospace and defense.
Argent provides AWS D17.1 fusion welding services through a Nadcap-accredited U.S. partner network. Class A, Class B, and Class C welds in Inconel, titanium, aluminum, and stainless — the specification that prime contractors and defense programs require for fusion-welded aerospace structural and flight hardware.
ITAR Pending · U.S. Suppliers Only · AS9100 Aligned · Seattle CNC Capacity
About The Specification
What AWS D17.1 covers and why it matters.
AWS D17.1 (current revision: AWS D17.1/D17.1M:2024 Specification for Fusion Welding for Aerospace Applications) is the American Welding Society's specification governing fusion welding of metallic flight hardware and ground support equipment for aerospace applications. It is the standard prime contractors, the Department of Defense, and the FAA reference for welded aerospace structures.
D17.1 defines three classes of welds based on criticality:
- Class A — Critical welds. Welds whose failure would result in loss of the aerospace vehicle, loss of major component, or loss of life. Highest inspection requirements, including 100% NDE on every weld. Examples: rocket engine combustion chamber welds, primary structure welds on crewed vehicles, pressure-bearing welds on flight hardware.
- Class B — Semi-critical welds. Welds whose failure would impair vehicle performance or cause significant economic loss but not vehicle loss. Inspection per drawing requirements, typically sampling NDE. Examples: secondary structure brackets, hydraulic plumbing on non-critical systems.
- Class C — Non-critical welds. Welds whose failure would not affect vehicle performance. Visual inspection only. Examples: ground support equipment, non-flight tooling, mounting brackets for non-load-bearing equipment.
The class is determined by the buyer (typically the prime contractor's engineering team) and called out on the drawing. The welder's qualification, weld procedure qualification, and inspection requirements all scale with the class.
What D17.1 requires beyond just "we can weld"
- Qualified weld procedure (WPS). A written procedure that specifies the welding process, base material, filler metal, joint design, preheat, interpass temperature, and post-weld heat treatment. The WPS must be qualified through a procedure qualification record (PQR) demonstrating mechanical properties.
- Qualified welders. Each welder must be qualified for each position and material combination they will weld, documented by a welder performance qualification (WPQ).
- Procedure and welder requalification. Qualifications expire and require periodic requalification per the spec.
- Non-destructive examination (NDE). Class A welds typically require 100% radiographic or ultrasonic inspection. Class B requires sampling per drawing. Class C is visual only.
- Material traceability. Base material and filler metal must be traceable to certified mill heat lots.
- Documentation. Weld maps, NDE reports, mill certs, and procedure compliance documentation ship with every welded assembly.
Capabilities
AWS D17.1 fusion welding capabilities.
Class A
Critical welds
100% NDE, qualified WPS and welders, full material traceability. Combustion chambers, primary structure, pressure-bearing.
Class B
Semi-critical
Sampling NDE per drawing, qualified procedures. Secondary structure, non-critical pressure plumbing.
Class C
Non-critical
Visual inspection. Ground support equipment, tooling, non-flight assemblies.
GTAW (TIG)
Primary process
Gas tungsten arc welding — the dominant aerospace fusion welding process. Best control, cleanest welds, lowest distortion.
GMAW (MIG)
Higher deposition
Gas metal arc welding for thicker section work where deposition rate matters and Class B/C inspection is acceptable.
PAW
Plasma arc welding
For precision and thin-section work, particularly on titanium and exotic alloys. Excellent heat control.
Materials we weld to AWS D17.1
- Inconel 718, 625, X-750, 600, 601 — combustor liners, rocket engine plumbing, turbine hot section
- Titanium 6Al-4V, 6-2-4-2, CP titanium — airframe structures, pressure vessels, propulsion components
- Aluminum 2219, 2024, 6061, 7075, 5052, 5083 — airframe primary and secondary structure, propellant tanks
- 17-4 PH, 15-5 PH, 304L, 316L stainless — structural fittings, hydraulic plumbing
- Hastelloy X, C-276, C-22 — corrosion-resistant high-temperature applications
- A286, Waspaloy — high-temperature aerospace structural
- Monel 400, K-500 — marine and chemical applications
Typical D17.1 weld applications
- Rocket engine plumbing and combustion chamber assemblies
- Aerospace pressure vessels and propellant tank welds
- Airframe primary structure (titanium, aluminum)
- Hot-section combustor liner assemblies
- Aerospace hydraulic and pneumatic plumbing
- Engine mount and structural bracket assemblies
Standards
Related specifications and quality requirements.
Specification
Process / Coverage
Common Applications
AWS D17.1/D17.1M:2024
Fusion welding for aerospace applications
Primary spec for all aerospace fusion welding
Nadcap AC7110/5
Nadcap audit criteria for fusion welding
Prime contractor Nadcap-required programs
AMS 2680
Electron beam welding
EBW for specialized aerospace welding
AMS 2681
Welding of aluminum alloys
Aluminum-specific welding requirements
AMS-STD-1595
Qualification of welders and welding operators
Defense applications, military aerospace
Export control regulation framework
Defense articles, controlled drawings, U.S. persons
Related Capabilities
Pairs well with.
Argent customers typically combine multiple capabilities on the same program. These are the most common pairings with this work.
FAQ
Common questions.
What's the difference between AWS D17.1 Class A, B, and C welds?
Class is determined by failure consequence. Class A welds are critical — failure would cause loss of vehicle or life (combustion chambers, primary structure, pressure-bearing flight hardware). These require qualified procedures, qualified welders, and 100% NDE. Class B is semi-critical — failure impairs performance but doesn't cause vehicle loss (secondary structure, non-critical plumbing). Sampling NDE per drawing. Class C is non-critical (ground support equipment, tooling). Visual inspection only.
Is AWS D17.1 the same as Nadcap?
No. AWS D17.1 is the technical specification for how to fusion-weld aerospace parts. Nadcap (AC7110/5) is an audit and accreditation program that verifies a welding facility has the procedures, training, equipment, and quality systems to consistently produce welds meeting D17.1 (or other specifications). Many aerospace primes require both: the welds must conform to AWS D17.1 AND the facility must be Nadcap-accredited. Argent partners with Nadcap-accredited facilities for prime contractor work.
What materials can be welded to AWS D17.1?
D17.1 covers nearly all common aerospace metals: aluminum alloys (2024, 2219, 6061, 7075, 5052, 5083), titanium alloys (6Al-4V, 6-2-4-2, CP), nickel-based superalloys (Inconel 718, 625, X-750, Hastelloy X, C-276), stainless steels (17-4 PH, 15-5 PH, 304L, 316L), and high-temperature alloys (Waspaloy, A286, Monel). Each material has specific WPS requirements covering filler metal, preheat, interpass temperature, and post-weld heat treatment.
Does Argent hold its own AWS D17.1 qualifications, or work through partners?
Argent partners with Nadcap-accredited U.S. welding shops that hold current AWS D17.1 qualifications across the materials and classes their facilities are certified for. Every RFQ is matched to a partner with the right qualification record, current welder certifications for the specified material and position, and Nadcap accreditation when required. We are transparent with buyers on every quote about which partner will perform the work and what their qualification status is.
What documentation ships with AWS D17.1 welded parts?
Welding procedure specification (WPS) used, procedure qualification record (PQR) reference, welder performance qualification (WPQ) records for each welder who touched the part, weld maps showing every weld and its class, NDE reports (radiography, ultrasonic, or penetrant per class requirements), material certifications for base metal and filler metal, and certificate of conformance. AS9102 FAI is included on production parts shipping to prime contractor programs.
AWS D17.1 weld nobody will quote?
Send us your weld drawing. Class A combustion chamber assemblies, titanium airframe primary structure, Inconel rocket engine plumbing — the welds primes can't get bid because shops can't hold the qualification or won't take exotic materials. That's the work we want.