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Reading the drawing, cutting the metal, measuring it, and the last sheet before it ships. The things this trade deals with every day, explained one at a time.

32 articles · page 3 of 4

Fe Materials13 min

S45C or SCM440: the logic behind choosing a material

Get the material wrong and the machining, heat treatment and surface treatment all have to be redone. This piece sets out the properties, machinability and typical uses of the ten materials Taiwanese machine shops meet most often, with an equivalent-grade table.

Corrosion, wear or appearance? How to choose a surface treatment

Surface treatment is not only about looks. It changes dimensions, affects fits, and can introduce hydrogen embrittlement. This piece compares coating thickness, corrosion resistance and cost, and explains how to call it out on a drawing.

The 3-2-1 principle, and three things never to clamp against

If the part does not sit still, the best machine and the best tooling count for nothing. This piece explains how the six degrees of freedom are removed one at a time, how the 3-2-1 principle is applied, and where clamping force should act.

A machine running 95% of the time can still have an OEE of 50%

OEE is availability multiplied by performance multiplied by quality. This piece explains what each factor deducts, where the six big losses hide, and why chasing 100% OEE is the wrong target.

How to write an 8D that does not come back rejected

A complaint arrives and you answer “training has been reinforced”, which is the same as not answering. This piece walks through what each D has to produce, the difference between containment and correction, and the points a reviewer will look for.

The new FMEA dropped RPN and uses AP instead

The 2019 AIAG-VDA edition replaced the RPN that had been used for decades with an Action Priority. This piece covers the seven-step approach, how to score S, O and D, and why multiplying them together misleads.

Wikimedia Commons・Gas Metal Arc Welding (Mig).jpg・CC BY-SA 4.0 Manufacturing processes11 min

Casting and forging differ by more than cost

Casting produces complex shapes; forging produces strength. This piece compares the two on process, achievable accuracy and defect types, and explains how the drawing tells you which the designer expected.

How tight is tight enough?

When you tighten a bolt with a torque wrench, only about a tenth of that torque becomes clamp load. This article covers the relationship between torque and preload, why the K factor drifts, and how well each anti-loosening method actually works.

How far back does a light curtain have to sit?

Fitting an interlock switch does not make a machine safe. This article walks through the risk assessment process, how PLr is decided, how the safety distance formula works, and how curtain resolution ties to mounting distance.