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Design guidelines are the geometry and tolerance limits a part has to respect to be made reliably and cheaply in a given process: wall thickness, draft, radii, hole and bend spacing, and achievable tolerance. There is one guide here per process, 15 in all, with typical values in inches and millimeters, the failure each rule prevents, and a DFM checklist.
DG-01, Fig. 5Rib proportions
Do. A rib 50–60% of the wall at its base, up to 3× the wall tall, with a small root radius: stiffness without a thick spot.
Avoid. A rib as thick as the wall doubles the mass where it joins, and the face behind it sinks.
15 guides and 181 rules, filed like a drawing register. Each guide opens with its rules in one table, then an interactive lab, a drawing for each rule, tolerances, material notes and a checklist.
Material flows or compacts into a tool. Walls, draft and radii rule.
Sheet, strip, wire and billet shaped by force. Bend radius, spacing and flow rule.
Material cut away by a rotating tool. Tool reach and setups rule.
Layer by layer, seam by seam, and the drawing package that travels with the part.
Six ideas show up again and again across the guides. Pick one to see it drawn, then switch the drawing to Avoid to see what goes wrong.
Principle 01Uniform wall
Do. Every wall within about 15% of nominal T, so the whole part cools and shrinks at one rate.
Avoid. A section twice as thick cools last: it pulls a sink mark into the face above it and can leave a void inside.
Typical tolerance on a general dimension, from each process's spec table. The line runs to what is achievable with extra process control or a secondary operation. Every tight callout costs money.
Springs are toleranced on load (typically ±10%) and offshore sourcing inherits the process, so neither sits on this scale. For how to write tolerances on the drawing, read the tolerance guide.
Design for manufacturing is shaping a part so the chosen process can make it reliably at the lowest cost: walls it can fill or form, draft it can release, radii its tools can cut, and tolerances it can hold without extra operations. Most of a part's cost is locked in by the drawing before a quote is ever requested.
Molded, cast and pressed parts cool, cure or compact at a rate set by their thickest section. A thick spot finishes last and shrinks after its surroundings are rigid, which leaves sink marks, voids and warp, and it sets the cycle time for the whole part. Even walls, with ribs for stiffness, avoid all three.
For machined parts ISO 2768-m is a common default: ±0.004 in (±0.1 mm) up to 0.24 in (6 mm), ±0.008 in (±0.2 mm) to 1.18 in (30 mm) and ±0.012 in (±0.3 mm) to 4.7 in (120 mm). Molded, cast and formed parts have their own standards, such as ISO 20457 and NADCA. Tighten only the features that need it.
No. They are industry-typical values for planning and design reviews. Each principal has its own equipment and limits, and the one quoting your part confirms what it can hold. When a number matters to the function, call it out on the drawing and ask for it in the RFQ.
Upload a STEP file to the part builder. It runs a DFM check on the geometry, flags walls, radii and features outside the typical limits for the process you pick, and gives a budgetary estimate. A rep then sends the RFQ to principals who run that process.
Check a part against the rules.
Upload a STEP file for an instant DFM check and a budgetary estimate, or send a drawing and a rep will route it to principals who run the process.