Choosing Between Aluminum, Mild Steel, and Stainless Conveyor Frames

The materials used to build a frame play a major role in a conveyor’s longevity, often before issues like belt speed or drive type even arise. Different materials are used depending on the situation, and choosing the wrong one can lead to rust, weld cracks, or a failed food safety audit within a year or two. Conveyor manufacturers must consider weight, corrosion resistance, and budget when selecting a frame material. Frame material is one of several decisions covered in our guide to choosing a conveyor manufacturer, alongside conveyor type, sanitary design, and line integration.

People Also Ask

Is aluminum strong enough for a conveyor frame? 

For light-duty, low-load conveyor applications, yes. Aluminum can’t carry structural load like steel and is best used on short conveying runs with lighter product.

Does mild steel rust in a food plant? 

Without the additional protection of powder coating, mild steel will rust quickly in a food manufacturing environment due to frequent washdowns. Any imperfections in the powder coating can let moisture reach the base metal, leading to new rust formations.

Why does stainless steel cost more than other conveyor frame materials? 

Chromium content and the harder fabrication process raise material and fabrication costs compared with other frame materials. However, stainless steel’s resistance to corrosion and cleaning chemicals far exceeds the alternatives.

Aluminum Conveyor Frames: Strengths And Limits

An aluminum conveyor frame will weigh a third of its steel equivalent at the same dimensions, which saves on shipping costs and makes for quicker on-site handling during installation. The metal resists surface corrosion naturally and keeps its good looks year after year without paint.

The catch is strength. Aluminum doesn’t carry as much structural load as steel, and repeated flexing over time will develop hairline cracks. It also fails to meet food-grade conveyor frame requirements when regular caustic washdown comes into play, as it will not hold up to the chemicals long term.

Strengths And Limits of Mild Steel Conveyor Frames 

Mild steel has the lowest upfront cost of the three and greater strength than aluminum at a similar frame size, making it a popular choice for dry, low corrosion applications like general assembly and packaging.

Mild steel will rust very quickly when left untreated, so most manufacturers will finish it as a powder-coated conveyor frame to provide a protective barrier.

The protective barrier only works while intact. A chip, scratch, or weld touch-up exposes bare steel underneath, and rust will spread from that exposure outward, even if the coating looks fine elsewhere.

Stainless Steel Conveyor Frames: Strengths And Limits

A stainless steel conveyor is more expensive than aluminum or mild steel of equivalent size and is the most expensive type to fabricate, but it resists corrosion over a broad pH range and has proven resistance to repeated caustic conveyor frame materials.

Frames constructed from stainless steel have been proven to withstand corrosion from repeated caustic conveyor frame materials and acid-wash-downs. The stainless steel frame maintains its look for years in service, with no need for a coating.

Stainless is the only of the three that reliably meets food-grade conveyor frame requirements in regulated environments, which is why CONOVEY ships Span Tech frames in either full 304 stainless steel or powder-coat-painted carbon steel, depending on the application requirements.

Comparing Conveyor Frame Materials At A Glance

Factor	Aluminum	Mild Steel	Stainless Steel
Relative weight	Lightest	Heavy	Heavy
Upfront cost	Moderate	Lowest	Highest
Corrosion resistance	Good, untreated	Poor, untreated	Excellent
Washdown chemical resistance	Weak	Weak, even coated	Strong
Food grade suitability	Generally no	No	Yes

Which Frame Material Fits A Washdown Conveyor Frame

Washdown frequency and intensity matter more than any other factor. A line occasionally hosed down with mild detergent can tolerate a well-maintained, powder-coated conveyor frame. A line that is subjected to day-to-day caustic foam or acid washes, normal in meat, dairy and ready meal production, needs stainless. Aluminum rarely has a place in a washdown conveyor frame once chemical exposure becomes normal, no matter how light or corrosion-resistant it appears on paper.

How Conveyor Manufacturers Match Material To The Application

An experienced conveyor manufacturer starts with the wash regime and load, not a standard material. Dry, low corrosion service rarely justifies the extra cost of stainless. Regulated food production rarely accepts anything less. 

Mixed environments and dry rooms adjacent to wet processing areas sometimes dictate stainless in the wet zone, but mild steel elsewhere on the same line, balancing frame cost to actual risk rather than over-specifying the whole line.

Matching Frame Material To Real Operating Conditions

The right frame material comes down to what the conveyor faces daily, not what costs least upfront. Aluminum suits light, dry, low load lines. Mild steel works for dry production where budget outweighs corrosion risk. Stainless Steel earns its higher cost anywhere washdown, food contact, or regulatory compliance is part of the job. To get the right price the first time, check what to include in a conveyor quote request, from wash regime to throughput.

Not sure which frame material fits your line? Contact the CONOVEY team at sales@conovey.com or 1 (844) 876 8889 to talk through your application.