A product team needs a soft-touch prototype that feels like the production grip, and the process options split three ways: overmold the soft material onto a substrate, cast it with a flexible urethane, or print it in TPU. Each route delivers a different combination of feel, durability, appearance, and lead time, and the right choice

A welded enclosure frame measures perfectly on the bench before welding and bows 3 mm across its open face the morning after. The welder did not do anything wrong; the heat of welding made the metal expand locally and then contract as it cooled, and the thin sheet did not have enough stiffness to resist

An electronics enclosure needs airflow, and the first design cuts a row of rectangular holes in the panel — which solves the heat problem and creates an EMI and dust problem. Vents in sheet metal are a trade between airflow, shielding, protection, and cosmetics, and the trade is decided by the vent geometry. Louvers punch

A robotic welding cell produces beautiful welds on one part and misses half the joint on the next, because the part tolerances, the joint access, and the fixture repeatability were designed for a human welder, not for a robot. Robotic welding thrives on consistency: the robot repeats the same path and the same process, so

A batch of anodized aluminum parts comes back with light spots at two corners — exactly where the parts hung on the rack during processing. The spots are not a coating defect; they are rack marks, and they were designed in when the drawing did not say which surfaces could carry contact points. Plating and

A plastic profile that measures perfectly at the extruder arrives undersized at the customer, because the profile kept shrinking after it was cut and cooled. Plastic extrusion tolerances are a material behavior story: the profile is shaped hot and cools to its final size, and the shrinkage, the cooling, and the die balance all move

A drone frame redesign needs to lose weight, and the material table offers three answers: magnesium is lightest, aluminum is the balanced default, and titanium is strongest for its weight. The table does not decide the part — the loading, the environment, and the manufacturing route do. Magnesium saves the most mass but demands corrosion

A machined batch arrives with a clean certificate of conformance, and the first assembly jams because the bore is 0.02 mm undersized at depth. The supplier’s report shows the bore “within tolerance” — measured at the mouth, where the gauge could reach. Incoming inspection exists to catch exactly this gap between the certificate and the

A threaded part passes its go/no-go gauge at the supplier and jams on the mating screw at assembly. The gauge said the pitch diameter was in range, and the screw still will not fit — because the thread is tilted, or the coating closed the fit after gaging, or the gauge was checking the wrong

A note that says M6, 10 mm deep leaves several decisions unresolved: pitch, tolerance class, usable full thread length and the clearance beneath it. Thread callouts turn those decisions into a manufacturable requirement. They also tell the inspector which thread form and limits the gauge must represent. Updated October 3, 2026 Use a complete designation