Design guide
Ten ways to make your part cheaper to machine.
The same advice Austin gives on the phone. Small design choices can make a big difference in cost and lead time. When in doubt, send the file and ask.
- 01
Give inside corners a radius
End mills are round, so a perfectly sharp inside corner needs extra operations like EDM or tiny tools. Add a radius a little larger than the cutter, and bigger is better on deep pockets.
Corner radius ≥ ⅓ × cavity depth
- 02
Keep pockets shallow
Deep, narrow pockets need long tools that deflect and chatter, so they have to cut slowly. If you need depth, open up the width or the corner radius too.
Cavity depth ≤ 4 × cavity width
- 03
Tolerance only what matters
Tight tolerances take extra time to machine and inspect. Call out ±0.0005″ where it truly matters, like bearing bores and mating features, and let the rest float at a standard tolerance.
Tight where it functions, standard everywhere else
- 04
Don't make walls too thin
Thin walls vibrate during cutting and can warp after. Plastics need even more thickness than metals.
Metals ≥ 0.030″ · Plastics ≥ 0.060″
- 05
Don't over-thread
Most of a thread's strength is in the first few turns. Extra depth adds time without adding much holding power.
Thread depth ≈ 1.5–3 × diameter
- 06
Use standard hole sizes
Standard drill and reamer sizes are faster and more consistent than holes that have to be interpolated or bored.
Standard sizes, depth ≤ 4 × diameter when possible
- 07
Design for fewer setups
Every time a part is flipped and re-fixtured costs time and stacks up error. Keep features on as few faces as you can. Our 4th axis helps with the rest.
Fewer faces = fewer setups = lower cost
- 08
Laser mark instead of deep engraving
Part numbers and logos can be laser marked or lightly engraved in-house. That's faster and cleaner than deep-cut text.
Text: laser mark or shallow engrave
- 09
Plan for finishes
Anodize and plating add thickness. Tell us whether dimensions are before or after finishing, and mask callouts for threads and bores that must stay bare.
Note pre- or post-finish dimensions
- 10
Send a print with the model
A STEP file shows the shape. A drawing shows what matters: tolerances, finishes, threads and critical features. Both together get you the fastest, most accurate quote.
STEP + PDF drawing = best quote
These are general rules of thumb. Every part is different. Send us your design and we'll tell you what actually drives its cost.
Ready when you are
Have a print? Put it in front of a machinist today.
Upload your STEP file and drawing, tell us quantity, material and timing. Austin reviews every request personally.