Q06 — TECHNICAL ANSWER
Acetal or Nylon for Industrial Gears?
Acetal holds tooth dimensions with low friction; nylon adds toughness and quiet mesh against steel partners. Neither is the better material in the abstract — acetal suits drives that must keep their mesh and run without lubricant, nylon suits drives that start under load or take shock.
Why acetal keeps its mesh
A gear is only as good as the tooth form it keeps under load and over time. A polymer that creeps or takes up moisture loses the form it was cut or moulded to, and a drive that has lost its mesh gets noisy well before it gets loose.
Acetal (POM) holds tooth dimensions with low friction, and that is the property being bought. Low friction matters for the same reason it matters on a bearing: a drive running without a lubricant film has to get low friction from the material itself. On food and grain lines, where lubricant near product is the thing being designed out, that is often the whole reason acetal is on the drawing.
It is also dimensionally steadier in damp conditions than nylon, which is why it tends to win in washdown positions where both would otherwise serve.
Why nylon survives the shock
Nylon adds toughness and quiet mesh against steel partners. Toughness is the deciding property on drives that start under load, reverse, or take an occasional jam — situations where acetal, being stiffer, is more likely to chip a tooth than to absorb the event.
Quiet running matters more than it sounds. Conveyor drives often run near people for entire shifts, and a nylon gear meshing against a steel partner is measurably quieter than the metal pairing it replaced.
The trade is moisture. Nylon absorbs more than acetal and its dimensions move with it, so a nylon gear in a permanently wet position needs that accounted for on the drawing rather than discovered in service.
What we treat as critical either way
The keyed bore must fit your shaft and the tooth form must mesh with the existing drive, so both are treated as critical features and verified against the drawing or the sample being replaced. A gear that meshes correctly but will not seat on the shaft is as unusable as one that does neither.
Nylon and acetal gears, sprockets and star wheels drive conveyors and transmit power where metal gearing would be noisy, need lubrication, or corrode — food processing and material handling being the classic cases.
We machine and mould these depending on the part and the quantity. A single replacement sprocket is usually faster machined; a repeat batch of the same form is better moulded, because the form is then reproduced identically each cycle.
Acetal and nylon gears — related questions
- Which is stronger, acetal or nylon?
- Nylon is tougher and better at absorbing shock; acetal is stiffer and holds its dimensions better. Which one is "stronger" depends entirely on whether the drive shocks or simply runs.
- Do polymer gears need lubrication?
- No, and that is usually why they are specified. Removing the lubricant from a drive near product is often the whole reason a polymer gear replaces a metal one.
- Can you match an existing gear without a drawing?
- Usually yes. Send the worn gear with photographs and the shaft size — the keyed bore and the tooth form are what we confirm before producing anything.
- Are your gears machined or moulded?
- Both, depending on the part and the quantity. A single replacement is usually faster machined; a repeat batch of the same form is better moulded.
Send your drawing or the worn gear with the shaft size, the drive it runs in and the quantity. We confirm the material, the keyed bore and the tooth form before producing anything. An NDA can be arranged before any detailed technical exchange.