Stainless Steel Circular Conveyor

What is Stainless Steel Circular Conveyor?

Author: ShanGong, Director of Engineering Department | Published: September 23, 2026 | Category: Circular Conveyor Systems

A stainless steel circular conveyor from TallMan Robotics is an oval or rectangular closed-loop line in which the parts that meet the product, the operator’s hands or the washdown hose are made from stainless steel, while the parts that carry load inside the machine are chosen for strength and wear. We build every line to the process it serves, so stainless is specified component by component rather than applied to the whole machine by default.

This page explains where stainless steel goes on a circular conveyor, what a hygienic conveyor needs beyond the material itself, and how one recent line was configured: a six-carriage oval, chain-driven, with 304 stainless steel working platforms.

Figure 1. The reference line: a horizontal oval loop with six carriages, 612 mm arcs and 660 mm straight sections.

Where Stainless Steel Goes on a Circular Conveyor

A circular conveyor has four groups of parts: the carriers that hold the product, the guideway they run on, the drive that moves them, and the frame that holds everything level. Each group sits in a different environment, so each has its own material decision.

The carriers are the first place to use stainless steel, because they are the surfaces the product touches and the surfaces an operator cleans. On the reference line all six working platforms were machined from 304 stainless steel.

The guideway is the second decision. Where the line will be washed down or run in a humid process, we can supply a 316 stainless steel guideway. Stainless guideway steel cannot be heat-hardened the way bearing steel can, so load and service-life figures for a 316 guideway are confirmed for each project rather than read from the standard tables.

The chain, sprockets and tensioning parts sit under the track and carry the drive load. On the reference line they are carbon steel, which suits a dry assembly environment. If they will be exposed to washdown, tell us at the enquiry stage so the drive materials and covers can be specified together.

Figure 2. Plan view. The carriages sit on the outer edge of the loop; the drive and chain run inside and below it.

304 or 316: What the Grade Changes

Both grades are austenitic stainless steels and both clean well, so the choice is decided by what touches the surface rather than by the product itself. 304 handles water, mild detergents and general food contact, and it is the usual grade for carriers and platework. 316 adds molybdenum, which is what makes the difference where chlorides are present — salt in the process, chlorinated cleaning agents, seawater-derived ingredients, or a washdown routine that uses disinfectant rather than plain water.

On a circular conveyor the parts at risk are the ones that stay wet longest: the guideway, where water collects between the rail and the roller path, and any crevice under a bracket. That is why the guideway is the component we offer in 316 while the carriers are usually 304 — the carriers are wiped and dry off, the rail does not.

One limitation has to be stated plainly. Stainless guideway steel cannot be through-hardened the way bearing steel can, so a 316 rail runs at a lower load rating and a shorter calculated life than the standard rail at the same size. We confirm both figures per project instead of publishing a single derating factor, because the answer depends on the carriage load, the index rate and the cleaning regime together.

Designing a Hygienic Conveyor: More Than Material

Stainless steel is necessary for a hygienic conveyor, but it is not sufficient. A line that must be cleaned regularly also needs three things decided early.

• Separation of zones. Keep the drive, chain and lubrication points below or outside the product zone, so the carriers pass over them rather than beside them. On an oval line with the drive under the track this comes naturally.
• A bellows cover protects the guideway and drive from water, oil, dust and spilled liquid. It was offered on the reference line as an option and is the usual choice where a line is hosed down.
• The guideway and rollers need lubrication, and in a food or pharmaceutical process the lubricant must be acceptable in that setting. Agree the lubricant with us before the line is built; a food-grade option is specified per project.

For wet or corrosive environments beyond occasional cleaning, see our IP65 circular conveyor system, which is built around sealing and drainage rather than material alone. If your process also needs the carriages to stop at fixed stations, our precision indexing circular conveyor page covers the station pitch and positioning side of the design.

Figure 3. Side elevation, 280 mm overall height. Everything that needs lubrication sits below the carriage plane.

Keep the Wet Zone and the Drive Zone Apart

On the reference line every driven part sits below the carriage plane: the chain runs in polymer guides under the track, the sprockets and tensioner sit inside the loop, and the gearbox and servo hang beneath the base plate. Nothing that needs lubrication sits above the product.

That layout is worth preserving when you plan the cell around the line. Water and cleaning solution run downward, so the drive zone needs a path for it to leave — a drip edge, a gap, or a tray — rather than a flat surface where it pools against a bearing seat. Where a line is hosed rather than wiped, the bellows cover keeps the water off the rail in the first place and turns the guideway into a sealed volume instead of an open channel.

Fixings deserve the same thought. Open tapped holes on an upward-facing surface hold water and cleaning residue; blind holes, sealed washers and screws that finish flush all reduce the number of places a residue can sit. Tell us where the line will be cleaned from, and we will orient the bracketry accordingly.

Reference Line: TMX01-V30-S612R180-Y460-6LK6-L660-C20

The line below was confirmed with the buyer on a signed technical specification form in February 2026 and built as a horizontal oval with six carriages and six positioning stations.

How the model code reads

TMX01 is the series. V30 is the 30 mm guideway. S612R180 describes the arcs: 612 mm diameter, 180° each. Y460 is the carriage centre distance. 6LK6 gives six carriages and six positioning stations. L660 is the straight length, and C20 is the chain drive.

Why the Loop Closes: Chain Pitch, Sprocket and Carriage Spacing

On a chain-driven circular conveyor the carriages are fixed to the chain, so the carriage spacing, the chain pitch and the sprocket have to agree exactly. This line uses C20 chain, a 20 mm pitch, and the 460 mm carriage spacing is 23 pitches. Six carriages give a loop of 6 × 460 = 2,760 mm, or 138 pitches.

The 72-tooth drive sprocket has a pitch circumference of 72 × 20 = 1,440 mm, so its pitch diameter is about 458.4 mm. The chain path is then the two straights plus one full turn at that diameter: 2 × 660 + π × 458.4 ≈ 2,760 mm. The arithmetic closes, which is why the carriages return to the same six stations lap after lap. Change the carriage count or the straight length and the loop has to be re-derived, because a loop that is not a whole number of pitches cannot be built.

Each index advances the chain one carriage spacing, which is 23 of the sprocket’s 72 teeth, or 0.319 of a sprocket revolution. Through the 30:1 gearbox that is about 9.6 motor revolutions per station.

Drive and Indexing in Stainless Steel Circular Conveyor

The line indexes on a 1.2 s cycle, and that figure covers the whole step: the move from one station to the next plus the dwell while the carriage is locked and worked on. Acceleration and deceleration must each be set to at least 0.2 s for smooth starting and stopping, so the move itself cannot be shorter than 0.4 s and the dwell available to the process is whatever remains of the 1.2 s after the move and the positioning stroke. When you specify a cycle, tell us how long each station needs, and we will size the move around it.

The drive runs from a 1.5 kW Delta servo through a 30:1 helical planetary gearbox to a 72-tooth sprocket on a C20 chain, with the carriages fixed to the chain at 460 mm centres. Each index turns the sprocket through 23 of its 72 teeth, which the 30:1 gearbox converts into about 9.6 motor revolutions per step.

Positioning Stations in this Stainless Steel Circular Conveyor

Each of the six stations locks the carriage with a pneumatic positioning unit: a compact cylinder drives a swing arm on a long shaft, and a CF8 follower engages the carriage’s positioning accessory. The positioning accuracy of a chain-driven line depends on this mechanism, not on the chain, because the chain always carries some slack and elongation. Our engineering guide on circular conveyor positioning accuracy on circular-motion.com explains how chain and belt lines compare.

Figure 4. Opposite isometric view, showing the drive side of the loop.

Cleaning, Lubrication and the Conflict Between Them

A hygienic conveyor has to be clean and lubricated at the same time, and the two requirements pull in opposite directions. Washing removes the film that protects the rail and the rollers, so a line that is cleaned daily needs lubricating more often than the standard interval assumes, not less. Plan the two tasks as one routine: clean, dry, then re-lubricate.

Two choices reduce the friction between them. A felt lubrication device carried on the carriage meters oil onto the rail continuously, so a wash cycle costs one recharge rather than a full re-application. And where the process allows it, a solid grease gives a long-interval film that survives wiping better than a spray.

The lubricant itself has to suit the process. We do not publish a food-grade option as standard, so if the line sits in a food, beverage or pharmaceutical process, agree the lubricant with us at the enquiry stage and we will specify the guideway, the device and the lubricant together.

Maintenance and Wear Parts for this Stainless Steel Circular Conveyor

A stainless steel circular conveyor still needs regular care. Before each shift, wipe the track and check that nothing obstructs the carriages. Tighten fasteners regularly if the machine sits near a vibration source, and stop the line to investigate any unusual noise. Do not adjust line components at random, because doing so can cost accuracy.

Lubricate the guideway and rollers with one of three approved lubricants: a spray-type penetrating lubricant (WD-40 class) every 3–5 days, a liquid guideway oil (ISO VG 46 class, such as Great Wall No. 46) every 2 weeks, or a solid lubricating grease for long-interval, effectively maintenance-free running. The intervals apply whether the lubricant goes directly onto the rail or into a fitted felt lubrication device. In a hygienic conveyor, agree the lubricant with us first so it suits your process.

Wear parts are customised to the line, so we recommend ordering a set with the conveyor.

What to Tell Us When You Enquire about a Stainless Steel Circular Conveyor

Material questions are answered faster with process answers than with a grade name. Six points settle a stainless steel circular conveyor specification.

• How the line is cleaned: wiped, sprayed or hosed, and how often.
• What is used to clean it: water, detergent, or a chlorinated or caustic agent.
• Whether the product touches the carrier, or sits in a tray or fixture.
• Whether the process is wet in normal running, or only during cleaning.
• Payload per carriage, index rate and dwell, so a 316 guideway can be rated properly.
• Any certification or documentation your auditor expects, so we can tell you at the outset what we can and cannot supply.

That last point matters. We supply material certificates and the components described above; we do not claim third-party hygienic design certification for this line, and the page you are reading states what was actually built rather than a specification aspiration.

Figure 5. Arc end detail: guideway, chain path and the carriage mounting interface.

Installation Checks

The reference line measures 1,456 × 796 × 280 mm and ships as one assembly in a plywood export crate. Check the doorways and lift sizes on the route to the installation point before delivery. The mounting frame should be flat to within ±0.15 mm over any 3 m, so the carriages run without binding at the arc-to-straight joints.

FAQ about Stainless Steel Circular Conveyor

Is the whole conveyor made of stainless steel?

Not by default. The product-contact carriers are stainless, the guideway can be 316 stainless, and the drive, frame and base plates are specified to suit the environment. We confirm each component’s material on the technical specification form before the line is built.

Can a stainless steel circular conveyor be washed down?

It can be designed for it. A washdown line needs a 316 guideway, protected drive components, bellows covers and an agreed lubricant. Tell us how the line will be cleaned, and we will specify the materials and covers together.

What payload can each carriage take?

The reference line carries 10 kg per carriage. Payload depends on guideway size, carriage design and, for 316 guideways, a derating that we confirm per project.

Which drive should I choose for a hygienic conveyor?

Chain drive gives a rigid, repeatable pitch between carriages and suits index-and-dwell processes like the reference line. Belt drive is quieter and runs without chain lubrication. The choice depends on your cycle, accuracy requirement and cleaning regime, so we recommend discussing it at the enquiry stage.

Does a 316 guideway carry the same load as a standard rail?

No. Stainless guideway steel cannot be hardened like bearing steel, so both the load rating and the calculated life are lower. We confirm the derated figures for your carriage load and index rate during quotation.

Can the drive chain be stainless?

Chain and sprocket materials are confirmed per project. The reference line uses carbon steel under the track, which suits a dry assembly process; a washdown line needs the drive materials, the covers and the lubricant specified together rather than one at a time.

Is this line certified for food contact?

We supply material certificates for the stainless components on request. We do not hold third-party hygienic design certification for the line as a machine, so if your auditor requires it, tell us before the design is fixed.

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