Wiper and Scraper Seals for Cylinder Rods

The rod seal retains oil, but it is the wiper that protects it. A rod that comes out wet with mud or covered in dust drags that contamination into the gland unless the wiper removes it. Failure of the wiper is one of the most common reasons for early rod seal damage and scored rods. In harsh settings, the wiper often wears first and should be replaced as a routine item.

Wipers are different from heavy-duty scrapers, which are made of metal or hard plastic and are used to cut through dried mud, ice or concrete. Many cylinders use a combination of a metal scraper outside and a polyurethane wiper behind it. Wipers work with the rod seal (see Rod Seals) and wear ring (see Wear Rings and Guide Rings) as part of the gland. The family overview is on Hydraulic Seals, and air-cylinder wipers are covered in Pneumatic Seals.

Single-acting wipers

Remove contamination from the rod on retraction only. The lip allows lubricating oil to pass out on extension. The most common type.

Double-acting wipers

A second lip retains oil film on the inside of the lip, giving some sealing in both directions. Useful where a thin oil film should be retained or a very clean environment is needed.

Snap-in wipers

Pressed into an open groove, usually with a small step to retain them. Quick to fit, with no separate retainer.

Press-in, metal-cased wipers

A metal case provides firm retention in a bored housing. Used on heavy equipment where the wiper takes impact.

Flanged wipers

A flange holds the wiper against a face and is retained by a cover plate or gland nut. Common on large cylinders.

Metal scrapers

Steel or brass scraper rings for ice, dried mud, concrete or hard deposits. Often used with a polyurethane wiper behind.

Wipers with integrated rod seal

Combined parts, mostly in compact cylinders.

These notes are typical and general. Always confirm limits against the manufacturer's data for your application.

• Polyurethane: excellent wear and tear resistance, widely used for wipers in mineral-oil cylinders. Some grades are sensitive to hot water and certain chemicals.
• NBR: economical and flexible, but less abrasion-resistant than polyurethane.
• FKM: higher temperatures and chemical exposure, such as in hot or aggressive environments.
• PTFE-based: low friction and chemical resistance, used in demanding or lubricant-free applications.
• Metal cases and scraper rings: steel or brass for retention and for cutting action. Corrosion protection may be needed.

1. Measure the rod diameter, and the groove diameter, width and depth. Our hydraulic seal measuring guide covers the method.
2. Identify the retention method: snap-in, press-in, flanged or retained by a cover.
3. Assess the environment: dust, mud, ice, washdown, chemicals or welding spatter.
4. Check the stroke speed and temperature, since fast, hot cylinders can overheat a lip.
5. Choose single or double-acting based on whether you need oil film retention.
6. Replace the wiper with the rod seal during a reseal. A new rod seal behind a worn wiper will fail early.

• Rod diameter and groove diameter, width and depth
• Existing wiper part number or markings
• Cylinder make and model
• Retention method, and whether the groove is open or closed
• Environment: dust, mud, ice, chemicals, washdown
• Temperature range and stroke speed
• Photos of the wiper and gland, and quantity

Genuine wipers are supplied by the cylinder or seal manufacturer. Compatible wipers follow the same profile and groove dimensions, and many common wipers are produced to widely-used profile standards by multiple makers. The difference is often in the lip geometry and polyurethane grade, which affect wear and life. For severe duty, check the material data for abrasion and hydrolysis resistance.

You can enquire about genuine or compatible wipers for equipment from manufacturers such as Hallite, Trelleborg and Freudenberg/Simrit.

Wipers are inexpensive compared with the damage they prevent, and are usually replaced in sets.

• Buy online: where a product is listed in the online shop with a confirmed price, you can order directly. Products are being added to the shop progressively, so not every item will be listed yet.
• Request a quote: for custom, bulk, unpriced or repeat-order requirements, send us a quote request with your details.
• Technical review: if you cannot identify the part, or the application is demanding, use Find My Seal or upload a drawing and our team will review it with you.

You can also call head office in Johannesburg on 011 079 6033, or WhatsApp 079 508 0989, or email info@globseals.com.

These guides support identification and troubleshooting.

• How to measure a hydraulic seal: measure the rod, groove and lip profile
• Common causes of seal failure: scored rods and contamination damage
• NBR, EPDM, FKM and silicone comparison: NBR, FKM and polyurethane compared for wipers