Which tools are NOT suitable for etching?

Files are primarily used for shaping, smoothing, and finishing surfaces, rather than etching. Etching typically involves using specific chemical solutions or abrasives to create designs or patterns on materials. The tools suitable for etching would facilitate precise control and application of those etching mediums, unlike files which can leave rough surfaces and are not designed for this purpose.

Locking pliers, duckbill pliers, and wrenches serve various mechanical tasks, but they do not contribute effectively to the process of etching, where more specialized tools are necessary.