Stainless steel link chain is the corrosion-resistant alternative to galvanised and alloy steel chain across three distinct application families: certified lifting under AS 4797 (Grade 50 / Grade 60 stainless), calibrated anchor and mooring chain for marine use, and general-purpose link chain for fastening, security, securing and architectural use. The three applications use the same physical product — welded stainless steel link chain in 304 or 316 — but with different certification, sizing convention and working load rating depending on what the chain has to do.
This guide separates the three. It covers grade selection (304 vs 316 vs 316L vs duplex), the strength derating from carbon steel (stainless lifting chain has roughly 50-70% of the WLL of equivalent alloy chain at the same diameter), the Australian and international standards (AS 4797, AS 3775, ISO 4565, DIN 766, ISO 3076), the calibrated chain conventions for marine windlasses, and the practical buying decisions — when stainless is worth the 3× cost premium over galvanised, and when it is not. For Australian workshops, AIMS Industrial stocks the link chain range at /collections/link-chains covering Austlift G304 stainless, Beaver brand and Inox World — galvanised, G70 and G80 alloy and stainless variants.
This article is for stainless LINK chain (welded link, non-drive). For stainless ROLLER chain (drive chain — power transmission on sprockets), see our Roller Chain Guide which now includes the dedicated stainless roller chain section. For pre-assembled chain SLINGS (lifting assemblies with master link and hooks — typically Grade 80 or 100 alloy steel), see our Chain Sling Guide.
Stainless link chain — the three application families
Welded stainless steel link chain serves three distinct industries with different requirements. Understanding which family applies is the first selection decision.
| Family | Use | Certification | Sizing convention | AU standard |
|---|---|---|---|---|
| Lifting chain | Overhead lifting, suspended loads, certified rigging — food, pharma, marine, chemical | WLL stamped, batch-certified to AS 4797 (Grade 50) or Cromox spec (Grade 60) | Diameter (mm) + grade | AS 4797 (G50), AS 3775 (slings) |
| Marine / anchor chain | Boat anchor rode, mooring, davits, dinghy lifting | Calibrated chain that fits windlass gypsies; some ISO 4565 / DIN 766 grade-rated | Diameter (mm) + chain length (m) + grade (G3, G40, G70 in carbon; equivalent stainless grades) | ISO 4565, DIN 766 (short link calibrated) |
| General-purpose link chain | Fastening, securing, gates, animal restraint, dog tie-out, security, decorative architectural | Uncertified (not for overhead lifting). Sometimes proof-tested but no WLL marking. | Diameter (mm) + form (short / regular / long link) | ISO 3076 (general short link), DIN 5685, BS 4942 |
The certification rule: if the chain will lift suspended loads above people or critical equipment, it MUST be certified lifting chain (AS 4797 Grade 50 stainless or AS 4344 Grade 80 alloy). Uncertified general-purpose stainless link chain is NOT rated for overhead lifting — even if the chain looks identical to certified lifting chain, the manufacture process and inspection regime are different. Using uncertified chain for lifting is a Work Health and Safety violation in every Australian state, and an insurance liability in the event of failure.
304 vs 316 vs 316L vs Duplex — stainless grade comparison
The grade decision determines corrosion resistance, cost and (occasionally) strength. For most industrial chain, 304 is the default. 316 is the marine and aggressive-chemical step-up. 316L and duplex are specialised.
| Grade | Composition | Best for | Avoid | Price vs galvanised |
|---|---|---|---|---|
| 304 (AISI 304 / 18-8) | 18-20% Cr, 8-10.5% Ni, no molybdenum | Food and beverage, pharmaceutical washdown, dairy, brewery, indoor industrial corrosive environments, dry chloride exposure (occasional splash) | Sustained salt water immersion, chloride mud anchoring, aggressive cleaning chemistries containing chlorides | ~3× galvanised |
| 316 (AISI 316) | 304 + 2-3% molybdenum | Marine atmospheric exposure, splash zone, coastal installations, swimming pool plant, aggressive cleaning chemistry, pharmaceutical sterilisation chemistry containing chlorides | Crevice corrosion under prolonged saturated mud anchoring (use duplex for this) — the molybdenum helps but does not eliminate the issue | ~4-5× galvanised (25-80% premium over 304) |
| 316L | 316 with reduced carbon (<0.03%) | Where chain is welded into custom assemblies (master links, attachment hardware) — the low carbon prevents sensitisation at weld zones | Standard stocked link chain typically isn't 316L unless specified — used in fabricated rigging | Similar to 316 |
| Duplex 2205 (318LN) | Roughly half ferrite / half austenite microstructure with higher chromium and lower nickel than 316 | Long-term saturated salt water immersion, sustained mud anchoring, premium marine anchor chain (Ketten Walder is the recognised premium German brand) | Cost premium of 30-50% over 316; specialty supply only — not standard stock | ~6-8× galvanised |
The magnet test for grade identification: 304 stainless is slightly magnetic (the nickel content allows some magnetic response), while 316 is significantly less magnetic. A strong rare-earth magnet picks up 304 chain noticeably; on 316 chain the pull is much weaker. This is a quick field check, not a definitive test — for guaranteed grade match, look for the manufacturer's marking on the chain link or master link, and request the material certificate from the supplier.
Crevice corrosion in 316 stainless anchor chain — the warm-water trap. Cruisers Forum field consensus: 316L stainless anchor chain in warm tropical or Mediterranean waters can develop crevice corrosion when the chain sits in saturated oxygen-poor mud for extended periods (multi-day anchorages). The chain looks fine externally but small pockets between links lose passivation and corrode rapidly. Duplex 2205 (such as Ketten Walder 318LN) is the recommended grade for permanent or long-term mooring in tropical / warm-saline mud. For day-anchoring in Australian temperate waters and active cruising patterns, 316 is fine — the chain spends time in oxygenated water and the passive layer regenerates between deployments.
Stainless lifting chain — Grade 50 (AS 4797) and Grade 60 (Cromox)
Stainless lifting chain is a different product specification from general-purpose stainless link chain. It is manufactured under the controlled conditions of AS 4797 (Grade 50) or equivalent international standard for Grade 60, every batch is heat-treated, proof-tested and individually marked, and the working load limit (WLL) is stamped on the chain at intervals along the length. The two stainless lifting grades stocked in Australia:
| Grade | Material | Standard | WLL vs alloy G80 | Typical AU brands | Use |
|---|---|---|---|---|---|
| Grade 50 stainless | 316 stainless steel, heat-treated | AS 4797 | Approximately 50% of equivalent G80 alloy WLL at same diameter | Beaver G50, Bridco, NEXO | Food and pharmaceutical lifting where alloy chain corrosion is unacceptable. Marine cargo handling. Chemical plant lifting where the chain washes down in chloride-containing chemistry. |
| Grade 60 stainless | Heat-treated stainless with optimised composition | Cromox proprietary (German), aligned with international Grade 60 conventions | Approximately 60% of equivalent G80 alloy WLL — closes the gap somewhat over G50 | Cromox (Bullivants, LiftQuip distribute in AU) | Higher-load stainless lifting — when standard G50 stainless is at the upper end of capacity. Premium cost over G50. |
WLL examples for Grade 50 stainless lifting chain (AS 4797, single leg, in-line straight pull):
| Chain diameter | WLL (single leg, kg) | Comparison: Grade 80 alloy WLL (kg) |
|---|---|---|
| 6 mm | 800 kg | 1,400 kg |
| 8 mm | 1,500 kg | 2,500 kg |
| 10 mm | 2,300 kg | 4,000 kg |
| 13 mm | 3,800 kg | 6,700 kg |
| 16 mm | 5,800 kg | 10,000 kg |
| 20 mm | 9,200 kg | 16,000 kg |
Reference values per AS 4797 (Grade 50 stainless) and AS 3775 (Grade 80 alloy), 4:1 safety factor applied to single-leg in-line pull. Multi-leg slings, choker hitches and bridle configurations apply de-rating factors to these values — see our Chain Sling Guide for full sling-configuration WLL adjustment, or refer to the manufacturer's tag on the chain or sling.
The stainless lifting chain identification system. AS 4797 Grade 50 stainless lifting chain is marked with raised lettering on the chain links: typically the manufacturer's identification, the grade designation (G50 or 50), and a batch traceability code. The chain or chain sling assembly carries an attached identification tag (typically stainless steel, laser-engraved or stamped) showing: WLL, chain diameter, grade, length, manufacturer, certification number, and inspection date. AS 3775.1 specifies the tag content — and the tag must be removable only by deliberate effort (not casually).
Stainless marine and anchor chain — calibrated for windlasses
Marine anchor chain has a unique requirement: it must run smoothly through the boat's anchor windlass without jumping or jamming. The windlass uses a chain wheel called a "gypsy" (or wildcat) that has pockets matching the chain's link dimensions exactly. Calibrated chain means the link dimensions are held to tighter tolerance than general-purpose chain so the chain meshes reliably with the gypsy.
Standard calibrated marine chain dimensions:
| Chain Ø (mm) | Inside link length (mm) | Outside link width (mm) | Standards | Typical WLL (G40, kg) |
|---|---|---|---|---|
| 6 mm | 18.5 | 20.0 | DIN 766, ISO 4565 | 1,150 kg |
| 8 mm | 24.0 | 27.0 | DIN 766, ISO 4565 | 2,000 kg |
| 10 mm | 28.0 | 35.0 | DIN 766, ISO 4565 | 3,200 kg |
| 12 mm | 36.0 | 43.0 | DIN 766, ISO 4565 | 4,500 kg |
| 13 mm | 36.0 | 46.0 | DIN 766 (G70 calibrated) | 6,700 kg |
| 16 mm | 49.0 | 56.0 | DIN 766, ISO 4565 | 8,000 kg |
Calibrated chain dimensions per DIN 766 short link standard. Tolerance on link dimensions is typically ±2% on inside length to ensure smooth windlass operation. WLL values shown are for Grade 40 carbon steel — stainless equivalents derate by approximately 30-40% (see grade comparison in lifting chain section).
Match the chain to the windlass. Before ordering anchor chain, identify the windlass make and model and confirm the chain size and standard the gypsy is cut for. A 10 mm DIN 766 chain will not run on a windlass cut for 10 mm BBB (American chain pattern with different link dimensions), even though both are 10 mm chain. Chain that doesn't match the gypsy jumps under load — exactly when reliability matters most. AU recreational and commercial vessels predominantly use DIN 766 / ISO 4565 calibrated chain; some older or US-imported boats use BBB or High Test patterns that need specialist supply.
Stainless anchor chain — the cost-benefit reality. Stainless anchor chain (typically 316 grade) costs roughly 3× galvanised carbon steel anchor chain. The benefit is corrosion resistance — galvanised chain loses its zinc coating over time and starts rusting, particularly in the splash zone and at the chain locker / windlass interface. A galvanised chain typically needs re-galvanising or replacement every 5-10 years on a working cruising boat; a 316 stainless chain in active cruising use can last 15-25 years before grade-related corrosion or wear ends its life. For a permanent moored boat, the maintenance saving partially justifies the upfront cost. For occasional weekend use, the economics rarely favour stainless. For long-distance cruising in tropical waters, duplex 2205 chain (premium) is the recommended choice.
General-purpose stainless link chain — short, regular and long link
General-purpose stainless link chain serves applications where corrosion resistance matters but lifting certification is not required: gate latches, dog tie-outs, animal restraint, security chain, decorative architectural use, swing chain on playgrounds, marine deck use, and countless light-duty fastening jobs. The chain is supplied in three link forms — short, regular and long — with the form chosen based on flexibility, weight per metre and aesthetic.
| Form | Inside link length | Use |
|---|---|---|
| Short link | Approximately 3× chain Ø | Calibrated chain (matches windlass gypsy), lifting chain. Shortest links per metre — denser, heavier, less flexible. Standard form for marine anchor chain and lifting chain. |
| Regular link | Approximately 4-5× chain Ø | The default general-purpose link chain. Balance of flexibility, weight and strength. Most common for fastening, security, decorative, and animal restraint applications. |
| Long link | Approximately 6-8× chain Ø | Lighter per metre. Higher flexibility. Used for light-duty marine, dog tie-outs, light security, and where the chain must drape or coil tightly. NOT calibrated — does not run on a windlass. |
Stainless link chain in 304 covers the bulk of general-purpose use; 316 is ordered when the chain is permanently exposed to sea air, splash, or salt mist. For decorative architectural applications (handrail balustrade infill, hanging signage, rope-rail style decoration), polished 316 is the typical specification because the chain remains visible and any corrosion staining is unacceptable.
Connecting and joining stainless chain — shackles, master links, quick links
Stainless chain is rarely used in isolation. It connects to other rigging hardware via stainless connecting links. The matching hardware must be in the same grade as the chain — connecting a stainless chain through a galvanised shackle defeats the corrosion-resistance purpose at the weakest point.
| Connector | Use | Grade match |
|---|---|---|
| Bow shackle (anchor shackle) | Connecting chain to anchor or to another piece of rigging — D-shape or bow-shape | 316 stainless for marine use, 304 for general industrial. See Bow Shackle Guide |
| D-shackle (chain shackle) | In-line chain connection where load is straight, not angled | 316 marine, 304 general |
| Master link | Connecting chain to a hook or load attachment point on a sling assembly | Must match chain grade — stainless lifting chain uses stainless master link rated to same WLL |
| Quick link (screw connector) | Threaded screw-closure link for general-purpose chain joining — NOT for lifting | 304 stainless for general; 316 for marine. Never use quick links in load-bearing lifting applications — the threaded closure cannot be certified for overhead lifting. |
| Coupling link / repair link | Permanently joining a broken chain or extending chain length — the link is closed by deformation and cannot be reopened without cutting | Match grade. Repair link is rated below the chain WLL — never use as primary connection in critical applications. |
| Swivel | Allowing chain rotation under load — typical between anchor and chain to prevent twist transferring to the anchor | 316 marine for anchor swivels; stainless lifting swivels rated to chain WLL for lifting use. |
The single weakest component in any chain assembly determines the total assembly working load. A G50 stainless lifting chain rated 1,500 kg (single leg, 8 mm) connected via a 1,000 kg master link is a 1,000 kg assembly. Always confirm every component rating before commissioning a lifting assembly.
Australian and international standards reference
| Standard | Coverage | Where it applies |
|---|---|---|
| AS 4797 | Grade 50 stainless steel lifting chain | The Australian standard for stainless lifting chain. Specifies material, manufacture, heat treatment, proof testing, marking, WLL ratings. |
| AS 3775.1 | Chain slings — short link, alloy steel and stainless | The Australian standard for chain sling assembly, including stainless variants. Specifies the master link, sling configuration, identification tag, inspection regime. |
| AS 3775.2 | Chain slings — fitting and use | Companion to AS 3775.1 covering field use, sling angle factors, choker hitches, basket hitches, multi-leg ratings. |
| AS 4344 | Grade 80 alloy steel lifting chain (non-stainless) | The standard for alloy lifting chain — referenced for context, not stainless. AS 4797 is the stainless equivalent. |
| ISO 4565 | Stainless steel anchor chains | The international standard for stainless anchor chain dimensions and proof loads. Common reference on premium imported anchor chain. |
| DIN 766 | Short link calibrated chain | The German standard widely used internationally for marine windlass-compatible calibrated chain. AU recreational and commercial vessels predominantly use DIN 766 chain. |
| ISO 3076 | General-purpose short link chain | International standard for non-lifting short link chain. Specifies dimensions and proof testing for general fastening, securing and decorative use. |
| DIN 5685 | Round steel link chain (general purpose) | Common European general-purpose chain standard — short, regular and long link dimensions. |
| BS 4942 | Short link chain for general use | British equivalent of ISO 3076. |
| NACM | National Association of Chain Manufacturers (USA) | American conventions — BBB chain, High Test, Proof Coil. Not common in AU but encountered on US-import boats. |
Sizing — how to specify stainless link chain
Stainless link chain is specified by four parameters: diameter, link form, grade and length.
- Diameter (mm) — measured across the round bar that forms the link. Common AU sizes: 4, 5, 6, 8, 10, 13, 16, 20 mm. Imperial sizing (1/4", 5/16", 3/8") encountered on US-imported equipment.
- Link form — short link (calibrated/lifting), regular link (general purpose), long link (light decorative or marine handling).
- Grade — 304 (general indoor industrial, food/pharma) or 316 (marine, aggressive chemistry). Lifting chain additionally specifies G50 or G60.
- Length — supplied by the metre or per box. Common lengths: 10 m, 30 m, 50 m, 100 m drums for general use; specific cut lengths for lifting chain assemblies.
A complete specification reads: "10 mm short link 316 stainless calibrated chain (DIN 766) — 30 m length, marine grade for anchor application." Or for lifting: "8 mm Grade 50 stainless lifting chain (AS 4797) — 4 m, with master link and grade 50 stainless lifting hook, certified single-leg sling."
How to identify stainless chain — grade and certification
| Check | What to look for |
|---|---|
| Magnet test | 304 picks up moderately on a strong rare-earth magnet. 316 has weak pull. Carbon steel chain pulls strongly. Useful first-pass identification but not definitive. |
| Surface appearance | 304 has a slightly warmer grey tone; 316 is typically a slightly cooler / brighter polished finish. Galvanised chain has a rough, mottled zinc coating. Hard to distinguish 304 vs 316 by eye alone. |
| Stamped marking on lifting chain | Lifting chain is marked at intervals (typically every fourth or sixth link) with the grade designation: G50, G60 or alloy grade equivalents. The manufacturer's logo and a batch traceability code are also visible. |
| Identification tag (lifting chain) | AS 3775.1 chain slings carry a stainless tag laser-engraved or stamped with WLL, grade, length, certification number, and inspection date. The tag is attached at the master link and removable only by deliberate effort. |
| Certificate of conformity | For purchased lifting chain, request the Certificate of Conformity from the supplier — a document showing batch number, material certificate (mill cert), proof load test record, and conformance to AS 4797 or equivalent. |
| Material chemistry test | For doubt cases, an XRF (X-ray fluorescence) handheld analyser identifies stainless grade in seconds and is the standard verification method in fabrication shops. |
Stainless vs galvanised vs alloy — when to step up to stainless
Stainless costs roughly 3× galvanised chain. The buying decision is whether the corrosion resistance justifies the premium. Use this matrix:
| Application | Recommended chain | Why |
|---|---|---|
| Indoor industrial lifting (factory, workshop) | Grade 80 alloy (galvanised or self-coloured) | Highest WLL per kg of chain; corrosion not significant indoors; lowest cost per lift |
| Outdoor lifting (yard, depot, occasional weather exposure) | Galvanised Grade 80 alloy | Zinc coating handles atmospheric exposure; reapply or replace at 5-10 years if rust starts |
| Coastal outdoor lifting (within 10 km of saltwater) | Grade 50 stainless (G316) | Salt air degrades galvanised faster; stainless eliminates the maintenance issue |
| Food and pharmaceutical lifting | Grade 50 stainless (G316) — non-negotiable | Zinc coating not food-safe; alloy steel rusts; only stainless meets cleaning chemistry compatibility and contamination risk standards |
| Marine recreational anchor chain (occasional use) | Galvanised G40 or G70 calibrated | Cost-effective; re-galvanise or replace at 5-10 years; stainless not justified |
| Marine cruising anchor chain (active long-distance use) | 316 stainless calibrated, or duplex for tropical / mud anchoring | Maintenance-free; the upfront cost amortises over 15-25 year service life |
| Permanent mooring chain | Galvanised G40 or G70 (replace annually-biennially) | The economics of permanent moorings rarely favour stainless — chain is checked and replaced regularly regardless |
| Decorative / architectural exterior | 316 polished stainless | Visible chain — appearance matters; 304 stains in coastal exposure |
| Animal restraint, dog tie-out | 304 stainless or galvanised long link | 304 is enough for most exposure; galvanised acceptable for short service life |
| Security chain (gate, vehicle, equipment) | Galvanised regular link, or 316 if exposed to weather | Cut resistance and pick resistance matter more than corrosion grade for security purpose |
AIMS Industrial stainless chain range
AIMS stocks the link chain range at /collections/link-chains covering galvanised, G70 transport, G80 alloy lifting, and stainless variants from established AU brands.
| Brand / product | Grade | Use |
|---|---|---|
| Austlift G304 Regular Link Chain Stainless Steel | 304 stainless | The general-purpose stainless link chain — marine and general fastening use. Stocked across common AU sizes 4-13 mm. |
| Beaver brand stainless lifting chain (G50) | Grade 50 stainless to AS 4797 | Certified stainless lifting chain. AIMS stocks Beaver brand across G70/G80 alloy lifting; G50 stainless variant available on request and through standard AU lifting chain supply chain. |
| Inox World stainless products | 304 and 316 | General industrial stainless — chain components and fixtures, including fasteners and connecting hardware. |
| Toho Chain Block Stainless Steel | Stainless lifting equipment | For stainless lifting setups — combines stainless chain block with stainless chain to create a fully corrosion-resistant lifting assembly. |
For specific application advice — particularly on lifting chain certification, marine anchor chain calibration matching to a specific windlass, or sourcing duplex grade for tropical marine use — call our team on (02) 9773 0122 or contact AIMS Industrial. We work with the standard AU lifting chain supply chain (Beaver, Bridco, Cromox via Bullivants and LiftQuip) and can source specialty stainless chain to AS 4797, ISO 4565 or DIN 766 specification.
Common stainless chain selection mistakes
- Using uncertified general-purpose stainless link chain for overhead lifting. The chain may look identical to certified Grade 50 stainless lifting chain, but the manufacture and inspection regime are different. Uncertified chain is not rated for lifting — using it is a WHS violation and an insurance liability.
- Over-specifying 316 where 304 would suffice. 316 costs 25-80% more than 304. For indoor food, pharma and dry industrial environments, 304 is the right grade — saving 30-50% on chain cost.
- Under-specifying 316 where chloride exposure is real. The opposite mistake — 304 in continuous salt spray, swimming pool plant, or sustained chloride mud anchoring will pit-corrode within months. 316 is the correct grade for these environments.
- Mismatching chain and gypsy on marine anchor chain. A 10 mm DIN 766 chain will not run on a windlass cut for 10 mm BBB pattern. Confirm windlass gypsy specification before ordering.
- Connecting stainless chain to galvanised hardware. The corrosion-resistance benefit is lost at the galvanised connector. Match grade through every component of the assembly.
- Treating stainless as same WLL as alloy at the same diameter. Grade 50 stainless lifting chain is approximately 50% of Grade 80 alloy WLL at the same diameter. Calculate from the stainless tables, not the alloy tables.
- Skipping the master link / hardware match for stainless lifting. Every component in a lifting assembly must be rated to or above the chain WLL — and in stainless if the chain is stainless. Stainless lifting hooks and master links cost more than alloy equivalents.
- Using stainless chain in tropical mud anchoring without considering crevice corrosion. 316L can develop crevice corrosion under extended saturated mud anchoring. Duplex 2205 (Ketten Walder 318LN) is the recommended grade for permanent or long-term tropical mooring.
Stainless chain selection checklist
- Application family — lifting (certified, AS 4797), marine/anchor (calibrated, ISO 4565 / DIN 766), or general purpose (uncertified, ISO 3076).
- Grade — 304 for indoor food/pharma/dry industrial; 316 for marine atmospheric and aggressive chemistry; duplex for tropical mud anchoring.
- Form — short link (calibrated, lifting); regular link (default general purpose); long link (light marine, decorative, dog tie-out).
- Diameter — match to required WLL (for lifting) or to windlass gypsy (for anchor) or to application bulk (for general).
- Length — supplied by the metre, in fixed lengths (10/30/50/100 m drums for general use), or as cut lengths for lifting assemblies.
- Connecting hardware — shackles, master links, swivels in matching grade. Match the assembly's weakest link to the required WLL.
- Certification — for lifting, request Certificate of Conformity. For marine, confirm ISO 4565 or DIN 766 calibration. For general, no certification required but proof-tested chain provides assurance.
- Inspection regime — AS 3775.2 specifies the inspection schedule for chain slings; lifting chain in service must be inspected at intervals and recorded.
For complete coverage of related rigging and lifting hardware, see our Chain Sling Guide, Bow Shackle Guide, SWL vs WLL Guide, and Load Binder Guide. For non-stainless transport chain, see our Load Binder Guide covering Grade 70 transport chain. For stainless drive chain (roller chain on sprockets), see our Roller Chain Guide.
Frequently Asked Questions
Quick reference answers to the most common questions on stainless link chain selection, grade comparison, lifting certification, marine anchor chain and Australian standards.
What is stainless steel link chain used for?
Stainless steel link chain is the corrosion-resistant chain used across three application families: certified lifting under AS 4797 (Grade 50 stainless) for food, pharmaceutical and marine load handling; calibrated marine anchor chain (ISO 4565 or DIN 766) for boat anchoring and mooring; and general-purpose link chain for fastening, security, animal restraint, decorative architectural use and any application where corrosion resistance is needed but lifting certification is not. The grades are 304 (general industrial / food / pharma) or 316 (marine and aggressive chemistry).
What is the difference between 304 and 316 stainless chain?
304 stainless steel contains 18-20% chromium and 8-10.5% nickel, with no molybdenum. It provides excellent corrosion resistance for water, mild chemicals, food, pharmaceutical washdown and dry chloride exposure. 316 stainless adds 2-3% molybdenum to the 304 composition, which significantly improves resistance to pitting corrosion in saline, marine and aggressive chloride environments. 316 typically costs 25-80% more than 304. For most industrial chain applications, 304 is sufficient. 316 is selected for marine atmospheric, coastal, swimming pool and aggressive cleaning chemistry environments. A field test for grade identification: 304 is more magnetic than 316 — a strong magnet picks up 304 noticeably while 316 has a weak pull.
Is stainless steel chain stronger than galvanised chain?
No — typically stainless chain is weaker. Stainless cannot be quenched and tempered to the same hardness as carbon steel without losing its corrosion resistance, so the working load is lower at the same diameter. Grade 50 stainless lifting chain has approximately 50% of the WLL of Grade 80 alloy chain at the same diameter. Grade 60 stainless closes the gap to about 60%. Galvanised carbon steel chain (Grade 70 transport, Grade 80 alloy) is stronger than stainless at the same diameter because it has higher base material strength. The trade-off: stainless eliminates corrosion failure modes, galvanised eventually loses its zinc coating and starts rusting. Choose grade based on whether load capacity or corrosion resistance is the priority.
What is Grade 50 stainless chain?
Grade 50 stainless is the certified stainless steel lifting chain rating in Australia, manufactured to AS 4797. It is made from 316 stainless steel, heat-treated, proof-tested and individually marked with the grade designation. Grade 50 means the working load limit at the chain's maximum-rated condition (typically a 4:1 safety factor over the breaking load) is at the 50 grade level — approximately 50% of the WLL of equivalent Grade 80 alloy steel lifting chain at the same diameter. It is the standard stainless lifting chain used in food processing, pharmaceutical, marine and chemical lifting applications where alloy chain corrosion is unacceptable.
What is the Australian standard for stainless lifting chain?
AS 4797 is the Australian Standard for Grade 50 stainless steel lifting chain. It specifies the material (316 stainless steel), manufacture, heat treatment, proof testing, marking, and working load limit ratings. The companion standard AS 3775.1 covers chain slings (including stainless variants) — the master link, sling configuration, identification tag and inspection regime. AS 3775.2 covers field use, sling angle factors and multi-leg sling rating de-rating. Grade 60 stainless chain (Cromox specification, German origin) is also used in Australia under proprietary manufacturer specifications aligned with international Grade 60 conventions.
Can stainless chain rust?
Stainless chain can corrode under specific conditions but does not rust in the same way carbon steel does. The two corrosion failure modes for stainless chain are: (1) pitting corrosion — small localised pits develop in chloride-rich environments (saltwater, swimming pool chemistry); 304 is vulnerable, 316 resists pitting through its molybdenum content. (2) Crevice corrosion — corrosion in oxygen-poor crevices between links during sustained saturated mud anchoring (tropical mooring); even 316L can develop crevice corrosion in these conditions, while duplex 2205 grade is the recommended specification. In normal service — water exposure, atmospheric splash, food contact — both 304 and 316 stainless chain remain visibly bright and corrosion-free for decades.
How do I tell if a chain is 304 or 316 stainless?
Three methods. Field test: a strong rare-earth magnet picks up 304 stainless noticeably; on 316 the pull is significantly weaker. Both are much weaker than carbon steel chain. The magnet test is quick but not definitive — variations in cold working can affect magnetism. Marking: lifting chain is stamped with the grade designation at intervals along the chain. The chain or sling identification tag also shows the grade. Material test: for definitive grade verification, a handheld XRF (X-ray fluorescence) analyser identifies stainless grade in seconds and is the standard verification method in fabrication shops. For purchased chain, the supplier's Certificate of Conformity and material certificate (mill cert) confirm the grade for the batch.
What chain is best for marine anchor applications?
For active recreational boats with moderate use, galvanised G40 or G70 calibrated chain (DIN 766 / ISO 4565) is cost-effective and replaceable every 5-10 years. For active long-distance cruising boats where maintenance is a burden, 316 stainless calibrated chain offers 15-25 year service life at roughly 3× the upfront cost. For permanent moored boats with regular inspection, galvanised remains the standard — the chain is checked and replaced regularly regardless of grade. For tropical and warm-saline mud anchoring (Mediterranean, North Australian, Caribbean cruising), duplex 2205 stainless (Ketten Walder 318LN) is the premium choice — 316 can develop crevice corrosion in extended saturated mud, while duplex is immune. Critical: the chain must match the windlass gypsy specification — DIN 766, BBB or High Test patterns are NOT interchangeable even at the same nominal diameter.
Does AIMS sell stainless lifting chain?
Yes — AIMS Industrial stocks the link chain range at /collections/link-chains covering galvanised, G70 transport, G80 alloy and stainless variants. The standard stocked items include Austlift G304 stainless steel link chain (general purpose), Beaver brand chain (across G50 stainless lifting + G70/G80 alloy), Inox World stainless products, and Toho stainless chain blocks for fully corrosion-resistant lifting assemblies. For specific lifting chain certification (AS 4797 Grade 50 stainless slings with master link and rated hooks), call our team or send a specification — we work with the standard AU lifting chain supply chain to source certified assemblies to AS 3775.1.
What grade of stainless chain for food processing?
Grade 304 stainless chain is sufficient for most food processing applications — it handles water, food acids, dairy washdown chemistry, brewery and beverage environments without corrosion. Step up to Grade 316 if the cleaning chemistry contains chlorides (some industrial sanitisers), if the chain is exposed to salt or marine ingredients (seafood processing, salt-cured products), or if the food has aggressive natural acids (citrus, vinegar production). For lifting in food plants, use Grade 50 stainless lifting chain (which is itself manufactured from 316 stainless) to AS 4797 certification. Carbon steel chain (galvanised or alloy) is generally not appropriate for food contact processing — even galvanised can shed zinc particles during corrosion.
Is stainless chain magnetic?
All stainless steel is slightly magnetic to varying degrees, but stainless chain is significantly less magnetic than carbon steel chain. The order of magnetism: carbon steel chain (strongly magnetic) > 304 stainless (moderate magnetic pull) > 316 stainless (weak magnetic pull) > duplex 2205 (intermediate, depending on ferrite/austenite balance). The magnetic difference between 304 and 316 is the basis for the field magnet test for grade identification — a strong rare-earth magnet picks up 304 noticeably while the pull on 316 is much weaker. Cold working during chain manufacture (the bending and welding of links) can affect magnetism slightly, so the magnet test is indicative not definitive. For guaranteed grade verification, use the manufacturer's marking, identification tag, or XRF analysis.
What is the working load limit of stainless lifting chain compared to alloy steel?
Grade 50 stainless lifting chain (AS 4797) has approximately 50% of the working load limit of Grade 80 alloy steel lifting chain (AS 4344) at the same chain diameter. For example: 8 mm Grade 50 stainless single-leg WLL is approximately 1,500 kg, compared to 8 mm Grade 80 alloy at 2,500 kg. Grade 60 stainless (Cromox) closes the gap somewhat — approximately 60% of Grade 80 alloy WLL, so roughly 1,800 kg at 8 mm diameter. The lower stainless WLL is because stainless cannot be heat-treated to the same hardness as alloy steel without losing its corrosion resistance. To achieve the same lifting capacity in stainless, step up the chain diameter — typically one size larger than the equivalent alloy chain calculation indicates.
What is duplex stainless chain?
Duplex stainless steel has a microstructure that is roughly half ferrite and half austenite — different from standard 304 and 316 (which are fully austenitic). The most common duplex grade is 2205 (also designated 318LN by chain manufacturers like Ketten Walder). Duplex stainless has higher mechanical strength than 316 and exceptional resistance to pitting and crevice corrosion in chloride environments — making it the premium choice for sustained saturated mud anchoring, tropical mooring, and the most aggressive marine and chemical environments. Duplex chain costs approximately 30-50% more than equivalent 316 stainless and is available primarily through specialist marine and chemical industry suppliers — it is not standard stocked anchor chain. For a tropical cruising yacht with permanent or extended mud anchoring, duplex is the recognised premium specification.
Can I use stainless chain for overhead lifting?
Only if the chain is certified Grade 50 stainless lifting chain (AS 4797) or Grade 60 (Cromox specification). General-purpose stainless link chain — even when made from the same 304 or 316 stainless steel as lifting chain — is NOT certified for overhead lifting. The manufacturing process and inspection regime are different: lifting chain is heat-treated, proof-tested at 1.5× WLL, batch-traceable, and individually marked with the grade designation. Using uncertified stainless chain for overhead lifting is a Work Health and Safety violation in every Australian state and an insurance liability if the chain fails. Always confirm the chain is rated for lifting and request the Certificate of Conformity for purchased lifting chain.
How much does stainless chain cost compared to galvanised?
Stainless chain typically costs 3× galvanised carbon steel chain for the same size and length. 304 stainless link chain runs approximately 3× galvanised. 316 stainless adds 25-80% premium over 304, so roughly 4-5× galvanised. Duplex 2205 stainless is approximately 30-50% over 316 — roughly 6-8× galvanised. The cost difference reflects raw material prices (stainless steel is several times the cost of carbon steel), manufacturing complexity (stainless requires controlled atmosphere welding to maintain corrosion resistance), and the smaller production volumes for stainless chain. The buying decision: stainless is justified when the corrosion-resistance benefit (15-25 year maintenance-free service life vs 5-10 year galvanised replacement cycle) amortises the upfront cost. For occasional or short-service-life applications, galvanised remains the economical choice.