01
Joint and fit-up definition
Define joint type, gap, edge preparation, weld location, size/length and accessible acceptance criteria.
Evidence route
Controlled weld symbols, joint detail and fit-up limits
Fabricated assembly control
Sheet-metal welding: design the heat, sequence and release evidence together.
Welded sheet assemblies combine joint geometry, fit-up, heat input, restraint, shrinkage, cosmetic treatment and final dimensional risk. PartVerity defines the joint, fixture, sequence, criteria and inspection state before welding becomes an uncontrolled correction process.
Decision premise
Welding question: how will the joint be built and released without allowing heat or rework to redefine the drawing?
Engineering control
Six controls for welded sheet-metal assemblies
Distortion cannot be wished away. Weld volume, placement, sequence, access, restraint and correction must be planned around function and evidence.
02
Material and process
Confirm base material, filler/process where specified, surface condition and any qualification or cleanliness requirement.
Evidence route
Material identity, process basis and required qualification records
03
Fixture and datum strategy
Locate the assembly from functional datums, support vulnerable panels and define when restraint is applied and released.
Evidence route
Fixture concept, location scheme and free-state measurement point
04
Sequence and heat control
Plan weld order, balance, intermittent versus continuous requirements and cooling to manage cumulative shrinkage.
Evidence route
Approved sequence, heat-control notes and first-off observation
05
Visual and structural criteria
Separate appearance, profile, continuity and defect criteria from dimensional acceptance and any required NDT.
Evidence route
Acceptance standard, inspection method and result
06
Post-weld release
Inspect critical interfaces after welding, dressing and finishing, with rework and concession linked to the final part status.
Evidence route
Final dimensions, weld record, NCR/rework link and release owner
Decision matrix
Weld risk to control response
The correct response depends on joint function, material, geometry and applicable requirements—not on a generic welding preference.
| Assembly risk | Control response | Evidence focus |
|---|---|---|
| Large thin panel | Balanced sequence, fixture and heat minimisation | Flatness/profile after release |
| Critical mounting interfaces | Datum-led fixture and staged verification | Hole/face relationship after welding |
| Cosmetic visible seam | Process, dressing and sample criteria | Visual standard plus dimensional status |
| Load-bearing joint | Engineering-defined weld and required qualification | Joint record and specified inspection/NDT |
| Mixed welded and coated assembly | Compatibility and process-sequence review | Cleanliness, masking and final functional evidence |
Claim boundaries
Welding claims that require context
A qualified welder does not by itself qualify the complete part route.
A visually smooth seam does not prove joint integrity.
A fixture-held result does not prove free-state geometry.
Grinding or straightening is not automatically acceptable rework.
Technical context
Use guidance to frame the review—not to replace project evidence.
Technical context for shrinkage, weld volume, balancing, presetting, sequence and fixturing. Project welding requirements and acceptance standards remain controlling.
Lincoln Electric weld-distortion guidance