Custom Stainless Steel 304 - Spring Energized Seal Springs

Q: Is 304 magnetic after cold working?

Annealed 304 is essentially non-magnetic, but cold working increases magnetic permeability (a normal effect when forming springs).

Get Instant Precision Quote →

event2025-10-9
person handaseal
textsms Read: 8

Type 304 (UNS S30400) is the classic “18-8” austenitic stainless steel widely used for springs, strip and wire when good formability, weldability and corrosion resistance are required. It can be supplied annealed for forming or cold-worked to high strengths for spring applications. For related materials and guidance see our Materials index and the Stainless steel category.

Contents

Introduction & quick summary
Core characteristics
Typical applications
Forming into springs & spring types
Alternatives & comparison
Selection guidance
FAQ
References

Introduction & quick summary

Stainless Steel 304 is an austenitic chromium-nickel stainless steel (commonly ~18% Cr, ~8% Ni) that balances corrosion resistance, formability and strength. It is commonly used where springs must be stainless and can be cold-worked to high strength (strip/wire) while retaining ductility. For higher corrosion resistance (chloride environments) or sour service consider 316L / 316 or nickel alloys such as Inconel 625. For high-fatigue or SSC-critical energizers see Elgiloy and MP35N.

Need 304 spring wire/strip or technical support? Request a quote — include desired temper (e.g., 1/4, 1/2, full-hard), operating temperature range and environment.

Core characteristics

Typical chemical composition (wt%) — representative

Note: shown ranges are typical for commercial 304; Fe (iron) is the balance. Always confirm exact lot values on the supplier mill certificate.

Element	Typical (wt%)
Iron (Fe)	Balance (≈ 70–75%)
Chromium (Cr)	17.5 – 20.0
Nickel (Ni)	8.0 – 11.0
Carbon (C)	≤ 0.08
Manganese (Mn)	≤ 2.0
Silicon (Si)	≤ 1.0
Phosphorus (P)	≤ 0.045
Sulfur (S)	≤ 0.03
Nitrogen (N)	≤ 0.10 (varies)

Key physical data (typical)

Typical physical & mechanical data for 304 (flat-rolled/wire forms). `` values use SI units (density kg/m³, moduli & strengths Pa, temperatures K). Always verify with your supplier for the exact temper & diameter used in springs.

Property	Stainless Steel 304 (typical)
Density	8.00 g/cm³ — (8000 kg/m³)
Elastic modulus (E)	≈ 193×10⁹ Pa — (≈ 193 GPa)
Shear modulus (G)	≈ 77×10⁹ Pa — (≈ 77 GPa)
Tensile strength (UTS) — typical range	≈ 520–720 MPa (range) — (representative midpoint shown: 620 ×10⁶ Pa). Actual UTS depends on temper and product form.
Yield strength (0.2% offset) — typical	≈ 210 MPa — (210×10⁶ Pa typical for wrought/annealed sheet).
Min service temperature	≈ −196 °C (≈ −320.8 °F) — suitable for many cryogenic uses (verify product form).
Short-term / intermittent max (oxidation resistance)	≈ 870 °C (≈ 1600 °F) intermittent; continuous oxidation resistance is commonly given to ≈ 925 °C (≈ 1700 °F) depending on atmosphere.
Recommended long-term continuous (conservative for springs)	≈ 260 °C (≈ 500 °F) — above this range cold-work benefits/strength and corrosion resistance may degrade; for high-temperature springs consult supplier data.
Form availability	Wire, strip, sheet, plate, bar — commonly available in annealed and multiple cold-work tempers (1/4, 1/2, 3/4, full-hard). For springs, order spring-tempered wire/strip from specialty suppliers and request temper charts.

Typical applications

Spring-energized seals and canted coil springs where stainless corrosion resistance and high cold-work strength are needed. See our Canted Coil Spring and Helical Spring product pages for examples.
Compression and tension springs, strip springs, fasteners and architectural/consumer goods.
Food processing, beverage, and general chemical exposure at ambient to moderate temperatures where 304’s corrosion resistance is sufficient.
Oil & gas auxiliary components in non-sour service — see our Oil & Gas Springs page for typical use-cases and qualifications.

Forming into springs & spring types

Summary: 304 achieves strength primarily through cold working (rolling, drawing, coiling). Typical spring forms include canted coil, helical, cantilever (V/U) and full-contact springs. For design guidance and examples see our product pages: Full Contact Springs, Cantilever V Springs and Cantilever U Springs.

Forming & finishing notes

Strength is developed by cold work — select temper consistent with required UTS and fatigue life (confirm with supplier temper charts).
Cold work can increase magnetic permeability (annealed 304 ~ non-magnetic; cold worked → slightly magnetic).
Electropolish/passivation improves corrosion fatigue life and reduces initiation sites in aggressive media.
For critical spring energizers always request supplier stress-relaxation curves at the intended operating temperature and representative corrosion/fatigue data in the actual fluid. If sour or H₂S-containing service is possible, consult our materials index and relevant CRA pages (Nickel alloys and Cobalt-Nickel alloys).

Alternatives & comparison

Comparison to help shortlist alternatives. Values are indicative engineering guidance — verify with supplier datasheets and mill certificates for the selected temper/diameter.

Material	Best when	Typical strength (UTS)	Service temp guidance
Stainless 304 (UNS S30400)	General-purpose stainless springs: excellent formability & cold-work hardenability	≈ 520–720 MPa (depends on temper)	Long-term ≤ ≈ 260 °C (≈ 500 °F); intermittent up to ≈ 870 °C (≈ 1600 °F)
Stainless 316 / 316L	When chloride resistance (pitting/crevice) is more critical	Comparable UTS ranges	Similar temp guidance; better chloride resistance than 304
17-7 PH	When high spring strength + heat-treatable preload retention are required	Very high (precipitation hardened)	Limited by precipitate stability; consult supplier — see 17-7 PH page for details
Inconel 625 / Elgiloy / MP35N	When SCC/SSC, very high temperature or extreme fatigue resistance is dominant	High — alloy/temper dependent	Often better high-T and SCC resistance than 304; choose based on chemistry & temperature — see Inconel 625 and Elgiloy pages.

Selection guidance

Direct selection pointers for spring energizer design:

Choose 304 when you need good general corrosion resistance, easy formability and the ability to cold-work to high strengths at ambient/moderate temperatures.
Choose 316/316L when chloride pitting/crevice corrosion is a concern.
Choose 17-7 PH / Elgiloy / MP35N when highest fatigue, SSC resistance or elevated-temperature preload retention is required.

Quick validation checklist

Confirm required temper & corresponding UTS / yield from supplier temper charts.
Request stress-relaxation data at the intended operating temperature for the selected diameter/temper.
Run representative corrosion + fatigue tests in the actual process fluid & temperature if service is critical.

FAQ

Q1: Is 304 suitable for spring energizers in chloride environments?

A1: 304 provides good general corrosion resistance but is more susceptible to chloride pitting than 316/316L. For chloride-rich or sour environments consider 316/316L or nickel alloys (Inconel/Elgiloy/MP35N) depending on SSC risk.

Q2: Which tempers of 304 are typical for springs?

A2: Spring tempers are achieved by cold-work (1/4, 1/2, 3/4, full-hard). Choose temper to meet required UTS and fatigue life and verify with supplier temper charts.

Q3: What continuous temperature is safe for 304 springs?

A3: Conservatively, long-term spring mechanical performance is expected ≤ ≈ 260 °C (≈ 500 °F); above this, strength and corrosion resistance can degrade — request supplier stress-relaxation curves.

Q4: Is 304 magnetic after cold working?

A4: Yes — annealed 304 is essentially non-magnetic, but cold working increases magnetic permeability (a normal effect when forming springs).

304