How Photo Etching Compares in Cost
Many design platforms now offer some basic cost estimating for the fabrication processes that are already programmed in. But NONE of them know anything about photochemical machining, so how can you be expected to know whether etching might be your best option.
An industrious team from the UK set about to answer these questions and present them in a side-by-side format. They created a series of five increasingly-intricate 1-inch stainless parts and had them quoted in quantities of 100, 5000 and 50000 pieces by six different methods. The results are as intuitive as you might expect. What's new is that they were able to express economic comparisons.
For example, for a simple one-inch disk for 100 pieces, wire EDM is the most economical choice, followed by laser, water jet and then etching. Wire EDM was about 30% of the cost of the etched part.
At the other end of the spectrum, take 50000 pieces of a 1-inch diameter x .005" thick screen with .006" holes: in this case, only etching and electroforming were viable solutions at comparable prices.
Stamping doesn't become advantageous until the 50,000 piece level due to the impact of the tooling costs. But at the fourth level of part complexity, the amortization of the tooling cost puts stamping at nearly twice the cost of etching. Wire EDM is about twice the cost of etching at the 5000 piece level. Water jet is more than 5 times etching at the 5,000 piece level, and is not even a consideration at the fourth and fifth levels of complexity. Surprisingly, laser doesn't make a compelling case at any level of complexity or quantity.
Designers and engineers are woefully uninformed about the capabilities and costs of chemical etching. As a result, they must try to fit some projects around the limitations of other processes. We've seen this happen many, many times. A lot of time, money and effort is wasted; sometimes tens of thousands of dollars and months of effort. Part of the beauty of etching is that we can put parts in your hands in a couple of weeks for about $600.
We've put a lot of info out here about the chemical etching process, including design rules, tolerances and costs.