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Stainless Steel

Corrosion-proof.
Medical-grade.
Autoclavable.

304, 316L, 17-4 PH and specialty grades. From food-service hardware to implant prototypes to aerospace structural components. Full passivation and electropolishing in-house.

01 · Grades & variants

Common stainless grades.

Five grades cover the vast majority of stainless steel applications. The right choice comes down to corrosion environment, strength, and whether you need to heat-treat.

304 / 304L

Food · general · most common

General-purpose austenitic. Excellent corrosion resistance for most environments. Non-magnetic in annealed state. Non-heat-treatable. 304L has lower carbon for better weldability.

316L

Marine · medical · chemical

Adds molybdenum (2–3%) for superior chloride resistance. Standard for marine, medical implants, pharmaceutical, and chemical processing. Low carbon version for welded assemblies.

17-4 PH

Aerospace · precipitation hardened

Martensitic precipitation-hardening. Heat-treatable to 1,100 MPa yield. Aerospace shafts, valve bodies, flight hardware. H900, H1025 and H1150 tempers.

303

Free-machining

Adds sulfur and selenium for improved machinability — turns 2–3× faster than 304. Used for high-volume turned parts: shafts, bushings. Slightly less corrosion resistant than 304.

15-5 PH

Aerospace · high strength

Similar to 17-4 PH with better transverse toughness. Aerospace structural applications requiring precipitation hardening.

Duplex 2205

Oil & gas · offshore

Two-phase austenitic-ferritic. Exceptional stress-corrosion cracking resistance. Offshore, chemical processing, pulp and paper. NACE MR0175 capable.

02 · Why this material

What makes stainless stainless.

The defining property is the chromium oxide passive layer that self-heals on exposure to oxygen. This single feature drives every design choice with stainless.

Corrosion resistance

Self-healing Cr2O3 passive layer resists attack from water, most chemicals, and biological fluids. Enhanced in 316L with molybdenum.

Biocompatibility

316L certified for short-term implant contact. Standard alloy for surgical instruments, bone plates, medical fixtures.

High temperature

Maintains strength to 500 °C (304) or 800 °C (316). Oxidation resistance to 900 °C and beyond.

Hygienic surface

Electropolished or passivated surfaces are FDA/USDA compliant for food, dairy, pharmaceutical and medical.

03 · Applications

Where stainless is the answer.

Medical instruments

316L surgical tools, bone screws, retractors — passivated, electropolished

Pharmaceutical hardware

316L tanks, piping, valve bodies — cGMP finish Ra 0.4 µm

Marine hardware

316L cleats, pulpits, rigging — chloride-resistant

Aerospace

17-4 PH valves, shafts, actuators — H1025 or H900 temper

Food & dairy

304 tanks, fittings, conveyor parts — 3-A sanitary

Chemical processing

316L, duplex 2205 reactor bodies, heat exchangers

Oil & gas

Duplex, 316L downhole tools — NACE MR0175 sour-service

Architectural

304 #4 brushed railings, facades, kitchen appliances

Firearms & sport

17-4 PH, 440C cutlery and firearm components

04 · Finishing

Finishing options for stainless.

Passivation

ASTM A967 citric or nitric — removes free iron, enhances Cr oxide layer. Required for medical.

Electropolishing

Electrochemical polish removes surface irregularities. Reduces bacteria adhesion. Used for pharma.

Bead blasting

Uniform matte cosmetic finish. Hides small surface defects. Common for medical instruments.

#4 brushed

Unidirectional polish pattern. Architectural appliance finish. Non-directional ("#7") on request.

Mirror polish

Up to Ra 0.05 µm (SPI-A1 grade) achievable. For optical and show-surface applications.

Laser etching

Permanent mark for serial numbers, logos, regulatory markings. No paint, no wear-off.

Titanium coloring

Heat or electrochemical coloring produces surface oxide in gold, blue, purple. Surgical tool coding.

Chrome plating

Hard chrome for wear surfaces. Decorative chrome for cosmetic. Thickness 5–25 µm.

FAQ

Stainless Steel questions.

316L contains 2–3% molybdenum that 304 does not. Molybdenum dramatically improves resistance to chloride-induced pitting corrosion — the mechanism that attacks stainless in salt water, chlorinated pools, and bodily fluids. 316L is standard for marine, medical and food processing. 304 is fine for most indoor applications.
Yes. 304, 304L, 316, 316L, and duplex grades weld well via TIG or MIG. "L" grades (low carbon) avoid carbide precipitation at weld HAZ. 17-4 PH welds but requires post-weld heat treatment. We follow AWS D1.6 weld procedures with qualified welders.
Yes. Passivation per ASTM A967 with copper sulfate test (or equivalent verification) is documented on the certificate of conformance. For medical and pharmaceutical customers we provide the full test method, lot number, and results.
17-4 PH is precipitation-hardenable, achieving yield strengths 5× that of 304 (1,100 MPa vs 205 MPa). Raw material cost is higher (roughly 1.5× 304), and heat treatment adds processing steps. Specify 17-4 PH only when strength is the driving requirement.
It depends on the grade and condition. Austenitic grades (304, 316L) are non-magnetic in the annealed state but can become weakly magnetic after cold working or welding. Ferritic (430) and martensitic (17-4 PH in some tempers) are magnetic. For MRI-safe parts, specify annealed 316L.
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