Stainless Steel CNC Machining Services

Choose 316 when the part sees saltwater, chlorides or acids — the molybdenum content resists the pitting corrosion that attacks 304 in those environments. Choose 304 for general-purpose corrosion resistance indoors, in fresh water or in food service. The cost difference is not only the material: 316 has a machinability rating around 36% against 45% for 304, so cycle times and tooling costs rise as well. If your part will never see chlorides, specifying 316 adds cost without adding function.

Almost entirely machining time. Stainless requires lower cutting speeds, absorbs more heat at the tool tip and wears tooling far faster, so the same geometry takes several times longer to cut than in aluminum and consumes more inserts along the way. Work hardening also means more conservative passes and more in-process inspection. Material cost is a secondary factor. The most effective way to reduce a stainless quote is to review the geometry and the grade before release rather than negotiating the price afterwards.

±0.01 mm on milled and turned features, and down to ±0.001 mm on Swiss-turned small-diameter work. Untoleranced dimensions default to ISO 2768-m. On stainless in particular we recommend tolerancing only the features that control fit and function — holding a tight band on every dimension multiplies inspection time as well as machining time.

Austenitic stainless grades harden when deformed. If a cutting edge rubs rather than cuts — because it is dull, because the pass is too light to form a chip, or because the tool dwells — the surface it passes over becomes significantly harder than the parent material. The next tool then has to cut through that layer, which accelerates wear and can break small tools outright. In practice it means stainless is machined with deliberate, consistent chip loads and tooling replaced on schedule rather than run to failure.

In most cases yes, and for medical, pharmaceutical and food-contact parts it is effectively mandatory. Machining embeds free iron from tooling and fixtures into the surface, and the passive chromium oxide layer cannot form over it — so a part that is dimensionally perfect can still rust in service. Passivation to ASTM A967 or AMS 2700 removes that iron and restores the oxide layer. Specify the standard and test method on the drawing rather than writing "passivate" alone.

No — anodizing applies to non-ferrous metals such as aluminum and titanium. For colored stainless we use PVD coating, which produces a hard metallic finish in black, gold and similar tones, or black oxide for a matte non-reflective surface. Electropolishing and mechanical polishing are the routes to a bright finish without adding a coating.

17-4PH is machined in Condition A and then age-hardened to the condition your drawing calls for — H900 for maximum strength through H1150 for greater toughness. The part changes dimension slightly during ageing, predictably enough to compensate for, so the condition must appear on the drawing before we quote. Where the post-ageing tolerance is very tight, we finish-grind after heat treatment instead of compensating.

Yes, with no minimum order quantity. Single prototypes and repeat production programs run in the same facility, so a design moving from validation into volume does not require qualifying a new supplier — and the process documentation built during prototyping carries into production.