LX Gas Spring Resource
Compare SS304 and SS316 stainless steel gas springs for marine, food, pharmaceutical and washdown equipment. Selection table, hardware tips and RFQ checklist.
Stainless steel gas springs are specified when a standard painted gas spring would rust: on boats, on food and pharmaceutical machinery that is washed down every shift, on outdoor equipment, and on medical devices that are wiped with disinfectants. The two grades buyers ask about most are SS304 and SS316. They look the same, but they do not behave the same once chlorides are involved.
Short answer: choose SS316 for saltwater, salt spray, de-icing salt, and chlorinated cleaning agents. SS304 can be enough for indoor, humid, or food-handling areas where chlorides are not present. If you are unsure, SS316 is the safer default for marine and washdown use.
Both are austenitic stainless steels with roughly 18% chromium and 8–10% nickel. The key difference is that SS316 contains about 2–3% molybdenum. Molybdenum strengthens the passive oxide layer against chloride ions, which cause pitting and crevice corrosion.
| Property | SS304 | SS316 |
|---|---|---|
| Chromium / nickel | ~18% / ~8% | ~17% / ~10% |
| Molybdenum | None | ~2–3% |
| Chloride (salt) resistance | Moderate | High |
| Typical pitting resistance (PREN) | ~18–20 | ~23–25 |
| Good fit | Indoor, humid, food areas without salt | Marine, salt spray, chlorinated washdown, chemical exposure |
| Relative cost | Lower | Higher |
PREN (Pitting Resistance Equivalent Number) is a standard way to compare how well a stainless steel resists pitting. A higher number means better resistance in chloride environments.
SS304 can be reviewed for indoor equipment in humid rooms, dry food-handling areas, and cleanroom furniture where there is no salt and no chlorinated cleaner. It costs less than SS316, but it can pit if chlorides are introduced later, for example when the cleaning chemical changes or the equipment is moved outdoors.
Standard LX gas springs use a painted carbon steel tube, a QPQ-treated piston rod, and a double-seal system. That construction suits most indoor furniture, cabinets, vehicles, and machinery covers. Stainless steel is worth the extra cost when:
A stainless gas spring mounted on plated steel brackets with zinc-plated fasteners will still corrode at the weakest point. Review the whole mounting system:
The LX Gas Spring laboratory in Changzhou has its own salt spray chamber for comparing coatings and stainless parts, together with force testers and multi-station endurance testers. LX gas springs have passed a TÜV fatigue test of 180,000 cycles, and all LX gas springs are covered by a 3-year warranty. For stainless projects, the salt spray duration and acceptance criteria are agreed with the buyer before samples are approved.
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Request a stainless steel gas spring quote or browse the full SS316 stainless steel gas spring range.
For marine, salt spray, and chlorinated washdown environments, yes. SS316 contains about 2–3% molybdenum, which gives it much better resistance to chloride pitting. For dry indoor use without chlorides, SS304 can perform well at a lower cost.
Annealed SS304 and SS316 are essentially non-magnetic. Cold working during tube and rod forming can make parts slightly magnetic, so a magnet test is not a reliable way to tell the grades apart.
Yes. Force depends on the gas charge and rod diameter, not the tube material. Stainless gas springs can be built to the force, stroke, and length the application needs.
Usually yes. A stainless gas spring with plated steel fittings will corrode at the fittings first. Specify the same grade for ball sockets, eyelets, clevises, ball studs, brackets, and fasteners.
Yes. LX Gas Spring (Changzhou Longxiang Gas Spring Co., Ltd.) manufactures SS316 stainless steel gas springs and gas struts for marine, food, pharmaceutical, chemical, and outdoor equipment, with custom force, length, stroke, end fittings, and lockable versions.