Stainless Steel Parts by Industry
Each industry brings its own grade, finish and paperwork. Medical and food have their own pages. The other common applications are below, with the decision that drives the grade and the documents to ask for.
Grade, risk and paperwork at a glance
Typical choices, not rules. The grade follows from what the part touches. Composition and PREN for each grade are in the grade reference, and the standards named here are explained on the standards page.
| Industry | Usual grades | What decides the grade | Finish and paperwork |
|---|---|---|---|
| Medical and dental | 316L, 17-4 PH, 416 for non contact | Sterilisation, body fluid contact, galling between mating parts | Passivation to ASTM A967, mill certificate, ISO 13485 where the part needs it |
| Food and dairy | 316L, 304L for dry service | Chloride from product and cleaning, cleanability | Ra 0.8 µm on product contact, 3-A geometry, passivation |
| Valves and fluid handling | 316L, 17-4 PH stems, 2205, Nitronic 60 | Pressure, galling at seats and stems, chloride | Mill certificate, hardness report, NACE MR0175 / ISO 15156 for sour service |
| Pharma and biotech | 316L | Cleanability, rouge, extractables | Electropolish, surface finish report to ASME BPE designations |
| Marine and offshore | 316L above water, 2205 or super duplex immersed | Sea water pitting and crevice corrosion | Mill certificate, PMI on request |
| Semiconductor and vacuum | 316L, 304L, 316LN | Outgassing, particles, magnetic permeability | Electropolish, precision cleaning, cleanroom packing |
| Chemical process | 316L, 2205, 904L | Acid and chloride service, weld zones | Mill certificate, low carbon grades for welded parts |
| Architectural | 304 indoor, 316 exterior and coastal | Appearance, tea staining near the coast | Finish sample, matched grain direction |
Valves and fluid handling
Valve bodies, stems and seats meet pressure, flow and repeated motion. 316L covers most wetted parts. 17-4 PH is the usual stem when strength is needed, and stainless on stainless sliding faces gall, which is why seats and stems are often a galling resistant grade such as Nitronic 60. Oil and gas sour service adds hardness limits under NACE MR0175 / ISO 15156, so name it on the RFQ.
Typical parts
- Ball, gate and needle valve bodies
- Stems, seats and trim
- Manifolds and instrument blocks
- Pump housings and impellers
- Compression and hydraulic fittings
- Sample and sensor ports
Pharma and biotech
Product contact parts in 316L, usually electropolished, with surface roughness reported against the ASME BPE designations the buyer names. Cleanability drives the geometry: no dead legs, no sharp internal corners, no crevices. Plan the finishing chain and its records with the drawing, not after it.
Typical parts
- Manifolds and valve blocks
- Sanitary fittings and ferrules
- Mixer and agitator parts
- Filling nozzles
- Bioreactor ports and probes
- Sampling valve parts
Marine and offshore
Chloride decides the grade. 316L serves above the waterline and in splash zones with regular washing. Fully immersed in warm sea water it pits and suffers crevice corrosion, which is where duplex 2205 or super duplex comes in. A PREN of about 40 or more is the commonly cited level for crevice resistance in sea water. 303 is off the table. Check PREN with the PREN calculator.
Typical parts
- Propeller and pump shafts
- Deck and rigging hardware
- Sea water pump and valve parts
- Subsea housings and connectors
- Fasteners and shackles
- Heat exchanger parts
Semiconductor and vacuum
What matters is what the part releases: gas, particles and residue. 316L and 304L are standard, 316LN where low magnetic permeability must survive machining and cold work. 303 stays out because its sulphur is a contaminant. Expect electropolishing, precision cleaning, a vacuum bake where specified and double bagging in a cleanroom. Gas system components are often specified to SEMI F20 for 316L material.
Typical parts
- Vacuum chamber ports and flanges
- Gas line fittings and weldment parts
- Wafer handling and chamber hardware
- Feedthrough and sensor bodies
- Showerhead and diffuser parts
- Valve and regulator components
Chemical process
316L is the baseline, 2205 when chloride stress corrosion cracking is a risk, 904L for sulphuric acid and similar service. Most of these parts are welded, so low carbon L grades keep the weld zone from sensitising. Describe the medium, concentration and temperature rather than naming a grade from habit.
Typical parts
- Valve and pump components
- Flanges and nozzles
- Heat exchanger tubesheet parts
- Mixer shafts and couplings
- Instrument housings
- Sample and dosing fittings
Architectural
Visible hardware in 304 indoors and 316 outdoors, especially within reach of sea spray, where 304 shows brown tea staining. The finish is the specification: brushed, satin, bead blasted or polished, agreed on a sample with the grain direction marked. Free iron from machining and handling causes rust spots, so passivation is cheap insurance on exterior parts.
Typical parts
- Glass spider and point fittings
- Balustrade and handrail fittings
- Cable and rod end fittings
- Door and gate hardware
- Bespoke brackets and anchors
- Signage standoffs
Keep reading
How these parts are made, and what each process does to a stainless part, is on the machining processes page.
- Materials
Machining 2205 duplex
Chloride resistance and strength, and what it costs to cut.
- Materials
Nitronic 60 for galling resistance
What galling actually is and when a grade change is the fix.
- Process
Passivation against electropolishing
What each one does and when a part needs both.
- Materials
316 against 316L against 316Ti
The low carbon L suffix and why it matters after welding.
Questions about industries
Something else? Email .
Is there a single stainless grade that suits every industry?
No. 316L is the most common answer for wetted and food, pharma or medical parts, but it is slow to machine. 303 cuts fastest and corrodes first. Duplex resists sea water and costs more to cut. The service environment picks the grade, and the grade sets much of the machining cost.
Do you match only medical and food work?
No. Medical and food have their own pages because they bring the most specific paperwork. We quote any machined stainless part: valves, pharma, marine, semiconductor, chemical process and architectural work included.
How do I tell you what my industry needs?
Write the environment and the documents on the RFQ: what the part touches, the temperature, the finish and the certificates you need back. We only place the work with shops that already work that way, and the certificates you ask for come back with the parts.
Send the drawing with the environment on it
We own no machines. Say what the part touches and which documents you need, and we send one itemised quote and place the work with a partner shop that already works that way. Reply within 24 business hours.