Design guidelines for anodized parts
Following a few basic design guidelines will help ensure your parts anodize properly and pass SendCutSend review.
Sizing & hole requirements
Sizing limits apply to flat parts before bending for sheet metal
Sheet Metal
| Min part size (flat) | 1″ x 3″ (≥ 3 in² surface area) |
| Max part size (flat) | 23″ x 23″ |
| Required hanging hole | ≥ .063″ (1.60 mm) |
| Min hole / cutout size | ≥ .040″ (1.02 mm) |
CNC Machined Billet
| Min part size (flat) | 1″ x 3″ x 1″ |
| Max part size (flat) | 7″ x 7″ x 12″ |
| Required rack feature | One ≥ .125″ through hole (best), or a threaded blind hole ≥ 4-40 / 3mm with ≥ 1.5× diameter depth |
- If your billet design can’t accommodate a hole, we can pinch opposing surfaces during racking.
- Expect small marks of discoloration at pinch points. You can specify preferred surfaces in your order note during configuration.
- If your material’s min hole size is larger than .063″, the hanging hole must match that larger size. Verify in the Material Catalog.
- Deburring is preselected on all anodized sheet metal parts. Media blasting is strongly recommended for billet.
What to expect with anodized parts
- Some surface imperfections may be visible through the anodizing
- Color finishes may vary batch to batch, and significantly between alloys
- 7075 T6 Aluminum will appear duller with more contrast between face and cut edge
- Bend lines will be visible (die protection isn’t available)
- Anodizing is non-conductive
- Scratches will expose raw aluminum beneath
- Type II anodizing adds ~0.0002″–0.0009″ per side to part dimensions
Parts requiring welding should not be anodized - Sheet: without deburring, all surface imperfections are enhanced
- Billet: as machined anodizes to a glossier finish and shows tooling marks more prominently. Media blasting anodizes duller and smoother, and better hides those marks
Additional anodizing resources
If you’re designing parts for anodizing, these resources may help:
Pre-flight checklist: Sheet Metal
- 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
Pre-flight checklist: CNC Machined Billet
- File is in a format that we accept for CNC machining (.step or .stp)
- Only one part is present in your design file (no assemblies)
- File is built at a 1:1 scale in either inch or mm units
- File does not include any extra faces or entities
- No holes or features are smaller than .125” (3.175mm)
- Internal features will have a minimum radius of .0625” (1.587mm)
- All internal features are accessible (e.g., not fully enclosed)
- No part marking, etching, or engraving included in the design