A 3D model tells the machine shop the shape. The 2D drawing tells it what matters: which dimensions are critical, how smooth a surface must be, which threads go where. A clear drawing gets you a faster quote and parts that are right the first time.
Send both a 3D model and a 2D drawing
Send a STEP file for geometry and a PDF drawing for requirements. If the two disagree, say which one governs. Put the same revision letter on both files.
Dimensions and tolerances
- State units (mm or inch) and the general tolerance in the title block, for example ISO 2768-m.
- Dimension functional features from the datums that matter in assembly.
- Give tighter tolerances or ISO fits (such as H7) only where function needs them.
- Use GD&T for flatness, position, concentricity or perpendicularity when a plus/minus tolerance is not enough.
Threads, holes and edges
- Call out threads fully: size, pitch, class and depth (for example M6×1-6H, 12 deep).
- Mark through holes and blind holes, and give blind-hole depth.
- Specify edge breaks, for example “break all sharp edges 0.2–0.5 mm”, and where sharp edges are required.
Material, finish and notes
- Material by standard designation and temper, for example 6061-T6 or EN AW-6082-T6.
- Surface roughness where it matters, for example Ra 1.6 on sealing faces.
- Finish and color (for example black anodizing) and surfaces to mask.
- Heat treatment and hardness, if any.
- Marking, packaging or inspection requirements you need on the parts.
Send your drawing
Upload your files through our quote form or email them to a0937121023@gmail.com. We review every drawing and suggest changes that make the part easier to machine.
Chi Xin Technology is a CNC machine shop in Nantun District, Taichung, Taiwan, founded in 2022. We run 5+ CNC machines — 4.5-axis CNC machining centers and CNC lathes — and mainly machine aluminum alloys and alloy steel, with a metal tolerance of 0.02 mm. We also offer wire EDM and surface finishing including anodizing, and we export to customers in Europe and North America.
Frequently asked questions
Can I send only a 3D model?
For simple parts, yes, if you also state material, finish and quantity. For parts with tolerances, threads or finish requirements, add a 2D drawing.
Which file format is best?
STEP for the 3D model and PDF for the drawing. IGES, DXF and native CAD files can also be used.
