Wiper seals: the first line of defence for a hydraulic cylinder
A wiper costs little but protects the whole cylinder: it keeps dust, mud and water from entering with the rod. Here is how to choose the right one.
Of all the seals in a hydraulic cylinder, the wiper is often the cheapest and the most neglected. Yet it works on the front line: it is fitted at the end of the cylinder head and, every time the rod retracts, it cleans the chromed surface of dust, mud, sand, water and chips. If the wiper does not do its job, dirt gets into the cylinder, damages the rod seal, scratches the chrome and contaminates the oil of the entire system.
Why contamination is so dangerous
Solid particles entering the circuit act as an abrasive. They wear seals, guides and sliding surfaces, and can also damage pumps, valves and control blocks. In agricultural, construction and quarry machines, where cylinders work outdoors and often in dust or mud, an effective wiper makes the difference between a cylinder that lasts for years and one that leaks after a few months.
The main types of wiper
Snap-in wipers
They fit into a groove in the cylinder head without any fastening elements. They are easy to install and very common in standard cylinders and mobile machinery.
Press-fit wipers (with metal casing)
They have an outer metal ring that is pressed into the housing. The fit in the head is very stable, so they suit harsh environments and applications with strong vibration.
Double lip wipers
In addition to the outer lip that cleans the rod, they have a second lip facing inwards which holds back the thin film of oil that passes the main seal. They improve overall sealing and are useful when you want the rod as dry as possible.
PTFE wipers or wipers with special elements
Designed for low-friction applications or particular conditions, for example when the rod works with ice, compacted mud or sticky residues.
Materials
Wipers are mainly made of polyurethane, highly resistant to abrasion and tearing, and NBR. For higher temperatures or special fluids, compounds such as FKM are used. On each profile's page on our website you will find the material and temperature indications.
How to choose a wiper
- Housing dimensions: rod diameter, outer housing diameter and height (plus any steps or chamfers).
- Mounting type: snap-in or press-fit, depending on the shape of the head.
- Working environment: dry dust, mud, water, ice, metal chips.
- Compatibility with the rod seal: some sealing systems work better with a double lip wiper.
Maintenance tips
- Always replace the wiper together with the rod seal: fitting a new seal behind a worn wiper shortens its life.
- Periodically check that the lip is not cut, hardened or deformed.
- Clean the rod before retracting it if it is covered with dried mud or concrete.
- Check the condition of the chrome: a wiper cannot protect a rod that is already scored.
In our catalogue you will find several families of wipers, with many sizes in stock. If you are not sure about the profile, send us the dimensions and a photo of the cylinder head: we will help you identify the correct wiper.
Frequently asked questions
Does the wiper also retain oil?
A standard wiper is mainly there to keep dirt out. Double lip versions also help retain the oil film, but they do not replace the rod seal.
Can I fit a press-fit wiper instead of a snap-in one?
Only if the housing in the head is suitable: the two types need different housing shapes. Always measure diameter, height and any steps before changing type.
Does a wiper deteriorate even if the cylinder is idle?
Yes: over time the elastomer ages, especially when exposed to sun, ozone and weather. On machines that stand idle for long periods, check the lip before resuming work.
What if the rod is always covered with dried mud?
Clean the rod before retracting it and consider a more robust or metal-cased wiper: hardened mud is one of the main enemies of seals.
