Design guidelines for welded parts
Following a few basic design guidelines will help ensure your parts are welded properly and pass SendCutSend review.
Sizing & hole requirements
Sizing limits apply to flat parts before bending
| Min part size (flat) | .375″ x 1.5″ |
| Max part size (flat) | 30″ x 44″ |
| Thickness range | .060″ – .125″ |
| Max root gap | .020″ |
| Min root gap | None (as long as the part bends without flange collision) |
- The root gap is the space between the two material faces the weld needs to fill. Our absolute process limit is .030″, but the .020″ max accounts for bending tolerances.
- You can measure root gap in Fusion 360 or a viewer like eDrawings.
- Verify thicknesses and grades in the Material Catalog.
Weld types we offer
- Corner weld: Two flanges meeting at a 90° corner.
- T-joint weld: A corner weld with an extended flange on the side.
Both can be applied to the inside (concave) or outside (convex) of the joint. For corner welds, the outside gives better material coverage. For t-joints, either works well.
Not currently offered: butt, lap, spot, stitch, continuous/fusion, or multi-part assembly welds.
Design considerations
- Design for bending first: Parts must be ordered with bending applied. See Bending Guidelines.
- Don’t model weld features: Don’t model fillets, weld beads, or any weld geometry. Model the bent part as you want it made; we handle the rest.
- Bend seams aren’t sealed: We don’t fill or seal bend relief gaps or open bend seams.
What to expect with welded parts
- Hand-guided process: Welding is done by hand, prioritized for strength and function over cosmetics.
- Pulse texture: Pulse welding produces a “stack of dimes” texture along the bead. This is normal and not smoothed (grinding coming soon).
- Weld variance: Up to .1″ deviation from the weld baseline is possible.
- Weld throat thickness: Typically ~1/16″ on thinner materials, ~1/8″ on thicker materials.
- Tack welds: May be used to hold the part in position. They won’t be visibly raised on the finished weld.
- Low heat-affected zone: Laser welding minimizes warping compared to MIG or TIG.
- Sharp edges remain: Edges at and around the weld are not softened unless specified.
- Not watertight or gas-tight: We can’t guarantee sealed welds.
- No certified welds: We don’t provide weld inspection reports or certifications.
- SendCutSend parts only: We can’t accept outside parts for welding. Parts must be ordered through SendCutSend.
Additional welding resources
If you’re designing parts for welding, these resources may help:
Pre-flight checklist
- File is in a format that we accept (2D: .dxf, .dwg, .ai, .eps; 3D: .step or .stp)
- All holes and cutouts are at least 50% material thickness for laser cut parts
- All holes and cutouts are no less than 0.070” for most waterjet cut parts
- All holes and cutouts are no less than 0.125” for all CNC routed parts
- File is built at a 1:1 scale, preferably in inch or mm units
- 2D files: all objects on the same layer, text converted to outlines, no open contours, all shapes united or merged, floating interiors bridged or stencilized
- 3D files: single solid sheet metal body, uniform thickness with a face at every edge, modeled at stock thickness with matching bend specs
- All stray points, duplicate lines, empty objects and text areas have been removed