Stainless Steel CNC Machining Services & Custom Metal Parts

303 is the free-machining grade and gives the best cycle time and finish, which makes it ideal for turned hardware and fittings. 304 is the general-purpose structural choice. 316L adds molybdenum for pitting resistance, so it is specified for medical, marine and food-contact parts. 17-4 PH is the choice when you need high strength after an aging treatment. 2205 duplex is for aggressive chemical and seawater service, and 420 / 430 cover high-hardness cutting tools and cost-effective decorative work respectively.

Two reasons: work hardening and poor heat conduction. Austenitic grades such as 304 and 316L harden rapidly under the cutting edge, so a tool that rubs instead of cutting will meet progressively harder material. Stainless also carries heat away slowly, so cutting temperature concentrates at the edge and accelerates tool wear. We manage this with sharp positive-geometry tooling, a depth of cut that stays below the hardened layer, generous flood coolant, and feed rates high enough to cut rather than rub.

Standard machined tolerance is ±0.025 mm, with precision features held to ±0.005 mm where the drawing requires it. As-machined finish is typically Ra 1.6 µm, and fine machining reaches Ra 0.8 µm. For medical and sanitary parts, multi-stage electropolishing takes bores down to Ra 0.2 µm, which also passivates the surface in the same operation.

Passivation to ASTM A967, electropolishing, bead blasting, brushed and mirror polishing, sandblasting, plus plating and coating where the application allows. Selection depends on corrosion resistance, cleanability, wear resistance and appearance. Passivation and electropolishing are the standard choices for medical, food and semiconductor parts because they remove free iron from the surface rather than covering it.

Yes. Every batch ships with a mill certificate (EN 10204 3.1 or equivalent) and heat-number traceability back to the source. Depending on your quality plan we also provide a First Article Inspection report, dimensional inspection reports, and CMM results for critical features. Third-party inspection or specific certification requirements should be flagged before quotation so the lead time can be confirmed.

Yes, and it is one of the more demanding things we do. Thin walls deflect under tool pressure and then spring back once released. We use Swiss-type lathes or supported setups to hold the work close to the cut, keep depth of cut light, choose insert geometry that minimises cutting force, and where required run an intermediate stress-relief stage between roughing and finishing. Wall thicknesses down to about 0.5 mm are achievable depending on diameter and length.

Prototypes and small batches typically run on a 3–7 working day cycle, and production quantities are confirmed against the volume and finishing route. Stainless machines more slowly than aluminum, so a part that would run in two days in 6061 may take three in 316L. We confirm the schedule with the quotation rather than after the order.

Yes. Stainless parts are frequently combined with sheet metal fabrication, welding, heat treatment and grinding to deliver a finished assembly rather than a single component. Keeping those routes with one supplier means the datum strategy carries through, which removes a whole class of fit problems that appear when each operation is quoted separately.