EDC finishes that survive a pocket: stonewash, bead-blast, anodize
A machined part with a sloppy finish looks worse than an average part finished well. What stonewash, bead-blast, Type III and PVD each do, and which to specify for EDC.
Finish is where EDC parts are judged. Nobody holds a knife scale up to a micrometer, but everyone runs a thumb across it. A well-machined part with a blotchy finish reads as cheap; an average part with a clean, even finish reads as expensive. It is worth more attention in the RFQ than it usually gets.
Stonewash
Parts are tumbled with ceramic or steel media until the surface carries a uniform matte swirl. It is the most forgiving finish in EDC: it hides handling marks, minor tool witness lines and the scratches the part will pick up anyway in month one.
Specify it for titanium and stainless knife parts, and for anything a customer will carry loose in a pocket with keys. Ask what media and how long — heavy steel media for too long rounds crisp edges, which matters if your design depends on a sharp chamfer line.
Bead-blast
Glass bead or aluminium oxide blasted at the surface for an even satin. Cleaner and more “production” than stonewash, which makes it the default on pen barrels and flashlight bodies where the design language is precise rather than rugged.
The trade-off: bead-blast shows fingerprints and wear faster than stonewash, and a blasted surface is slightly more corrosion-prone on stainless because of the increased surface area. On 416 or 440C, ask for passivation afterwards.
Titanium anodize (Type II)
No dye, no coating — the colour is an oxide layer grown to a controlled thickness by voltage, so the finish cannot chip off the way paint does. Purple, blue, bronze and gold are the standard EDC palette.
This is the finish that separates good shops from cheap ones. Uniform colour across a batch requires a fixture that holds every part at the same potential in the same bath. Get a sample set before production. Always.
Type III hard anodize
For aluminium, mostly flashlight bodies. A thick, abrasion-resistant layer in black, deep grey or olive drab. It adds roughly 25 to 50 microns per surface, which is enough to bind a thread that was machined to nominal — tell the shop the part is getting Type III before it is cut, so threads and close-fitting bores get relieved for it.
6061-T6 takes a more even Type III than 7075, which can come out with a slight greenish cast. If you need a true deep black, specify 6061.
PVD
Physical vapour deposition, for stainless and tool steel. Black, bronze, gold, blue. Harder and more scratch-resistant than anything above, and priced accordingly. Almost always outsourced, which means an extra handoff in the schedule — budget an extra one to two weeks and confirm who is managing the coater.
Laser marking
Fibre laser for logos, serial numbers and edition marks. Mark before the final surface treatment so the mark sits flush under it rather than on top of it. Marking after anodize burns through the oxide layer and leaves a raw metal scar, which is occasionally the intent but usually a mistake.
What to write in the RFQ
Name the finish, name the colour if there is one, and say whether you want a sample first. “Stonewash, ceramic media, keep the chamfer crisp” costs nothing to write and saves an entire prototype cycle. If you are still deciding between two, ask for both quoted — the delta is usually smaller than the reorder cost of guessing wrong.
Related: titanium Grade 2 vs Grade 5 covers how the alloy choice changes anodize colour.