The comparison usually arrives after a prototype that looked acceptable in one process and failed a test that the other process would have passed. Extrusion printing and resin printing overlap on price for small parts and on lead time for simple geometry, which is why the decision so often gets made on convenience. It should

Hardened tool steel changes the process plan. A block that machines easily at 30 HRC becomes slow, tool-consuming and risky at 58 HRC, and the features that define a mold or die, sharp internal corners, deep narrow ribs, precise clearance, become progressively harder to produce with a rotating cutter. Electrical discharge machining removes the hardness

Extrusion printing is often dismissed as the hobby process, and then specified anyway when the part is 600 mm long, has to sit in a paint oven, or needs to be replaced by lunchtime tomorrow. Industrial FDM solves a specific class of problem: large single-piece parts, high-temperature thermoplastics, tooling that must survive shop-floor handling, and

The most common failure in a printed bracket is not a bad design: it is a good design printed in the wrong direction. Extrusion printing bonds each layer to the one below it, and that bond is weaker than the material inside a layer, so a load that pulls layers apart finds the weakest plane

The features that stop a milling job are usually small, sharp and hard: a square internal corner in a hardened tool steel block, a deep rib narrower than any cutter, a slot through a part that has already been heat treated. Electrical discharge machining exists for exactly those features, and it is often the difference

A rapid tool is not a cheap version of a production mold. It is a deliberate instrument for answering a specific question: whether this design, in this material, produces a part that assembles, performs and sells. Teams that treat it as a discount on tooling usually spend the savings twice, once on a mold that

Both processes remove metal with electrical discharges, both cut hardened material without cutting force, and both are often quoted under the same line item. The difference that matters is geometric: one cuts a contour through the part, the other reproduces a shaped electrode in a blind cavity. Choosing the wrong one adds cost and can

The prototype is signed off, the tool is cut, and the first production parts do not assemble. In most cases the cause is not the tool: it is that nobody agreed which features were critical, how they would be measured, or what deviation would be acceptable at prototype stage. Welded and formed sheet metal parts

Two prototypes of the same enclosure can look convincing and prove completely different things. A printed part validates form, fit and appearance quickly and cheaply; a formed metal part validates the material behaviour, the assembly method and the manufacturing route that the product will actually use. Choosing between them is not a question of which

A sheet metal prototype is usually requested for one of two reasons: to prove that an enclosure closes, or to prove that the design can be manufactured at all. Those are different tests, and the drawing, the material and the inspection should differ accordingly. Sheet metal prototyping has one advantage over most other routes, which