A chain plate conveyor is a simple idea: two chains, a series of plates, and a frame strong enough to carry the load. In practice, the details that decide whether it lasts five years or eighteen months are thermal expansion, slat support and chain tension.
Key takeaways
- Slat material and thickness are set by temperature and impact, not by the average load.
- Thermal expansion must be allowed for at both ends of the conveyor.
- Chain tension should be adjustable and monitored; a tight chain wears faster than a loose one.
- Curves increase chain load and need a larger drive and heavier chain.
When a chain plate conveyor is the right choice
Use one when the product is hot, oily, sharp, heavy or needs to drain. Typical applications include stamping and forging lines, washing and drying tunnels, paint and coating lines, and assembly of heavy castings. The open plate surface lets oil and water fall away, and the chain can be specified for temperatures that would destroy a belt.
Do not use one for light, clean products where a belt or roller conveyor is cheaper and quieter. The chain and plates add mass, noise and wear points that are unnecessary for a 2 kg carton.
Slat design: thickness, material and surface
Standard slats are 2–4 mm mild steel, stainless steel or aluminium. For hot parts, stainless steel is common because it resists scaling and retains strength at temperature. For abrasive parts, a thicker slat or a replaceable wear strip is better than a thicker chain.
The slat surface should be flat enough that the product does not rock. A slat that is bent or uneven will concentrate load on one chain and cause premature wear. On heavy-duty conveyors, slats are often supported by a longitudinal wear bar in the centre, which reduces the bending load on the slat and the chain.
| Service | Slat material | Typical thickness | Chain |
|---|---|---|---|
| Light assembly, room temperature | Mild steel, powder coated | 2 mm | Roller chain, 1/2 in |
| Oily parts, washing | Stainless 304 | 2.5–3 mm | Stainless roller chain |
| Hot parts up to 400 °C | Stainless 310 or heat-resistant steel | 3–4 mm | Heat-treated chain, large pitch |
| Heavy castings | Mild steel with wear bars | 4–6 mm | Heavy roller chain, 1 in |
Thermal expansion
Steel expands by about 12 µm per metre per degree Celsius. A 20-metre stainless conveyor that rises from 20 °C to 300 °C grows by 20 × 280 × 0.000012 = 0.067 m, or 67 mm. If the frame and the chain are both restrained, that expansion becomes a buckling load or a broken chain.
Design the frame with slotted anchor points and a fixed end, so the conveyor can grow in one direction. Leave clearance at the take-up and at any fixed guards. For very long ovens, split the conveyor into sections with separate drives rather than trying to absorb the expansion in one frame.
Chain tension and take-up
The chain should be tight enough to stay on the sprockets and loose enough to allow thermal growth. A sag of 1–2% of the centre distance on the return run is a reasonable starting point. Use a screw take-up at the tail end with at least 100 mm of travel, and mark the initial position.
Check tension after the first week, then monthly. A chain that needs frequent re-tensioning is either stretching beyond its service life or is being overloaded. Replace it before it breaks; a broken chain on a loaded conveyor can damage the frame and the product.
Drive sizing for heavy loads
The drive must overcome friction, the weight of the chain and slats, the weight of the product, and any incline. For a horizontal conveyor, the chain friction coefficient is typically 0.1–0.15 with proper lubrication. Add a starting factor of 1.5–2.0 for a fully loaded conveyor.
On a curve, the chain friction increases because the chain is pulled against the guide. A 90° curve can add 20–40% to the chain tension depending on the radius. If the conveyor has multiple curves, calculate the tension at each section rather than applying a single factor to the whole length.
Curves and transfers
Curves are made with a curved track and a chain that can articulate. The slats must be narrow enough to follow the curve without binding, or the curve must use a separate slat design. A common mistake is to use straight slats on a tight curve; the slats overlap on the inside and gap on the outside, and the product tips.
At a transfer, the gap between conveyors should be small enough that the product cannot fall through, and the two conveyors should be at the same height. For heavy products, a transfer plate or a powered transfer is better than relying on momentum.
Frequently asked questions
Can a chain plate conveyor run through an oven?
Yes, with heat-resistant chain, slats and bearings, and with expansion designed into the frame. The drive motor should be outside the hot zone, or rated for the temperature.
How often should the chain be lubricated?
In a clean, room-temperature environment, every 200–300 hours. In a hot or dusty environment, use a high-temperature lubricant and inspect weekly; some oven conveyors run dry with a specially coated chain.
What is the maximum incline for a chain plate conveyor?
It depends on the product and the slat surface. For loose parts, keep the incline below 15°. For products in fixtures, 30° is possible with cleats. Above that, a different conveyor type is usually better.
Send the part weight, temperature and layout to our engineers via the contact page, and we will specify the chain, slat and drive together. See the chain plate conveyor page for standard configurations.
