Lubrication Accessories & Spare Parts Manufacturer & Exporter - Accessories

Frequently Asked Questions: Lubrication Accessories

What accessories come with a grease gun?

Most STAR grease guns ship with a rigid steel extension and a 4-jaw coupler with ball check. Professional and heavy duty models also include a flexible hose. Additional accessories like locking couplers, extra hoses, extension pipes and filler plugs are available separately from our grease gun accessories range.

What is a grease coupler?

A grease coupler (also called a grease gun coupler) is the connector on the end of a grease gun hose or extension that attaches to a grease nipple (zerk fitting) on machinery. It creates a sealed connection so grease flows into the bearing or joint under pressure without leaking. Our range includes standard 4-jaw push-on couplers, locking couplers, quick release couplers and hydraulic couplers.

What is the difference between a standard coupler and a locking coupler?

A standard push-on coupler snaps onto a grease nipple and is held by spring-loaded jaws. It can pop off under high pressure or if the fitting is worn. A locking coupler has a threaded collar or lever mechanism that clamps onto the nipple, creating a secure connection that won't release until you manually unlock it. Locking couplers are recommended for high-pressure applications and hard-to-reach fittings where a pop-off would waste grease and time.

What is a grease nipple (zerk fitting)?

A grease nipple (also called a zerk fitting or grease fitting) is a small threaded fitting installed on machinery at lubrication points. It has a spring-loaded ball check valve that opens when a grease coupler is pressed onto it, allowing grease to flow in. When the coupler is removed, the ball check seals to prevent grease from leaking out. We manufacture grease nipples in straight, 45° angle, 90° angle, button head and flush type configurations.

What thread sizes do grease nipples come in?

The most common thread sizes are 1/4"-28 UNF (standard in North America), 1/8" BSPT (common in UK, Australia and Asia) and M6, M8, M10 metric threads (used in European and Asian equipment). We manufacture grease nipples in all these thread sizes. Always check your equipment's existing fittings before ordering replacements to ensure the correct thread match.

Why does my grease coupler keep popping off?

The most common causes are excess pressure buildup, a worn coupler jaw, or a damaged zerk fitting. First check the zerk. If the ball check is stuck or the fitting is clogged, pressure builds up and pushes the coupler off. Try cleaning or replacing the fitting. If the coupler itself is worn, replace it with a locking coupler which clamps onto the fitting and won't pop off under pressure.

How do I unclog a grease nipple?

Remove the grease nipple from the equipment using a wrench. Soak it in solvent or penetrating oil for 15 to 30 minutes to dissolve hardened grease. Use a thin wire or needle to clear the ball check valve. Blow compressed air through the fitting to confirm flow. If the nipple is still blocked, replace it. Clogged nipples are usually caused by dirt contamination or using incompatible grease types.

What types of grease gun hoses are available?

We offer flexible rubber hoses (spring-braided for high pressure resistance), rigid steel extensions (4" to 12" lengths) and combination kits. Flexible hoses are essential for reaching fittings in tight spaces. Rigid extensions provide direct, precise delivery. Most STAR lever action and pistol grip grease guns accept standard 1/8" BSPT or NPT threaded hoses and extensions.

How do I choose the right oil can spout?

Choose based on access requirements: rigid spouts (4" to 9") for direct, precise delivery; flexible spouts for reaching around corners; combination spouts for versatility. We also offer 30° bent rigid spouts for angled access. All spouts are available as replacements for our oil can range. Spout variants are designated /R (rigid), /F (flexible) and /RF (combination).

Are your accessories universally compatible?

Yes. Our couplers, hoses, extensions and nipples use standard thread sizes (1/8" BSPT, 1/8" NPT, M10x1) that are universally compatible with standard threading. The 4-jaw coupler design fits standard grease nipples regardless of equipment brand. If you need a specific thread or fitting type not in our standard range, contact us for custom manufacturing.

Do you offer OEM accessory manufacturing?

Yes. We provide full OEM and private label manufacturing for all accessories with custom branding, specifications and packaging. We supply distributors and industrial buyers in over 27 countries. Visit our OEM partnership page for details.