S-735 Lever Action Grease Gun

Frequently Asked Questions: S-735 Dual Lever F-Type Cartridge Lever Action Grease Gun

What is a dual lever grease gun and how is it different from a single-lever model?

A dual lever grease gun has two handles that the operator grips and squeezes together to drive the pump, distributing the pumping effort across both hands rather than concentrating on a single lever wrist. The two-handed motion provides stability during high-pressure pumping, allows operators with smaller hands or less grip strength to use the gun comfortably, and works equally well for left-handed and right-handed operators without reconfiguration. Common in German and European industrial service for decades. On standard single-lever grease guns, the operator pumps with one hand while holding the coupler on the zerk with the other; the single-lever wrist does all the pumping work. On the dual-lever S-735, both hands share the pumping load, which reduces wrist fatigue on long service routes.

Why does the S-735 use a dual-handle design?

The dual-handle design is the German-style ergonomic preference for industrial lubrication tools, where two-handed stability during high-pressure pumping is valued alongside the operator's ability to maintain consistent pressure on the coupler throughout a service round. In German and European industrial lubrication culture, industrial-service tools are often designed for ambidextrous operation and symmetric effort distribution. The dual-handle S-735 is engineered to that convention. The practical benefit for operators: less wrist fatigue on extended service sessions, more stable body position during pumping (both feet planted, both hands on the gun, rather than one hand awkwardly holding a single lever), and easier use for operators with grip-strength or hand-size considerations.

What are F-type and LS-type threaded cartridges?

F-type and LS-type are threaded grease cartridge formats with specific thread profiles used primarily in German and European industrial lubrication supply chains. Both are vacuum-sealed cartridges that thread directly onto a grease gun's head port, eliminating the priming step that standard tube cartridges require. F-type is the more common of the two, with LS-type being a specific subset that uses a slightly different thread. Both formats are sourced from German and European grease manufacturers through industrial-supply distribution channels. They are not interchangeable with the worldwide 14 oz. (400 g) tube cartridge that dominates UK, North American, and most non-European markets. Cartridges are available in various grease grades (lithium, calcium, aluminium complex, polyurea) from the major German and European grease manufacturers.

Can I use standard 14 oz. (400 g) tube cartridges in the S-735?

No. The S-735 is engineered for F-type threaded cartridges (and F&LS-type on the /LS variant). The head's threaded port does not accept standard tube cartridges, which are a physically different format with a follower plate and no threaded interface. Attempting to use a standard tube cartridge in the S-735 is not possible: the cartridge cannot seat in the threaded port. For operators stocking standard 14 oz. tube cartridges, pick the standard-barrel STAR range (S-706 medium duty, S-707 heavy-duty flagship, or the full lever action grease gun category) which is engineered for that cartridge format.

What is the difference between S-735 and S-735/LS?

The standard S-735 accepts F-type threaded cartridges only; the S-735/LS accepts both F-type and LS-type cartridges in the same head, providing cartridge thread flexibility in mixed-format service operations. Mechanism, dual-lever handle, 7,500 PSI pressure rating, hose, and coupler are identical across both SKUs. Pick the S-735 if your operation stocks only F-type cartridges, which is the common case in most German and Austrian industrial supply chains; pick the S-735/LS if you service equipment from multiple OEMs that use different cartridge thread specifications, or if you're a distributor carrying both thread types and want one gun SKU to cover both without stocking separate guns.

How does vacuum technology on the S-735 eliminate priming?

The F-type (or F&LS-type) cartridge is manufactured with a vacuum-formed seal around the grease column inside the cartridge body, so there is no air gap between the cartridge and its own grease. When the cartridge threads onto the head's port, the vacuum seal engages the port and the grease column connects to the pump chamber with no air gap at the connection point either. Standard tube cartridges require priming after every reload because air enters the pump cavity when the head is opened to insert the cartridge; priming is how that air gets pumped back out. On the S-735, no atmospheric air enters the pump cavity during the cartridge change because the cartridge seal is already in place before the port is opened, so the priming step is mechanically unnecessary. First pump of the dual-lever handles after a fresh cartridge installation dispenses grease, not a dry stroke.

Does the S-735 support bulk loading, suction fill, or filler pump loading?

No. The S-735 is cartridge-only by design. The head's threaded spin-on port is specifically engineered for F-type (or F&LS-type) vacuum cartridges and is incompatible with bulk-grease inlets, suction-fill follower plates, or filler-pump pressure fittings. This is the deliberate trade-off: the dual-lever ergonomic advantage and the priming-free workflow come at the cost of the flexibility that 4-way loading would provide. For operators who need bulk fill or filler-pump loading alongside the dual-lever ergonomics, a different product line would be needed; the 4-way loading range (S-706 at 6,000 PSI, S-707 at 12,000 PSI) are standard-barrel tube-cartridge guns without the dual-lever handle.

Why is the S-735 rated at 7,500 PSI instead of 6,000 or 12,000?

7,500 PSI is matched to the German and European industrial service workload where F-type cartridges dominate: machinery arms, pivot joints, bushings, conveyor belt bearings, and machine-tool lubrication on well-maintained industrial equipment that may occasionally encounter modest crust buildup but rarely severe. 6,000 PSI medium-duty is adequate for clean light-industrial and workshop service, 12,000 PSI heavy-duty is for mining and outdoor construction service with severely crusted fittings. 7,500 PSI sits in the middle specifically to cover the German/European industrial service profile: above medium-duty for occasional crust clearing, below heavy-duty because that pressure tier would be over-specification (and cost more to manufacture) for the service use case that F-type cartridges are stocked to serve.

Is 7,500 PSI safe for bearing seals during service?

Yes. Bearing seals typically fail at internal grease-cavity pressures of 500 to 1,500 PSI, far below the 7,500 PSI maximum the S-735 can develop at a fully blocked fitting. Actual pressure reaching the bearing seal depends on the fitting's flow restriction: a clean zerk on a healthy bearing passes grease at low pressure. The 7,500 PSI specification is the maximum the pump can build when the coupler is blocked, not the steady-state pressure reaching the bearing. To prevent over-greasing, stop pumping the moment fresh grease appears at the bearing seal or the dual-lever resistance sharply increases. Damaged bearing seals leak oil and grease, allowing contamination ingress; controlled pumping avoids that.

Can the S-735 at 7,500 PSI cause a grease injection injury?

Yes. Grease injection injuries from 7,500 PSI grease guns are documented in emergency medicine and require immediate surgical treatment. A pinhole in the hose or unseated coupler can drive grease through intact skin at 7,500 PSI. The initial wound looks like a tiny puncture and often does not hurt much initially; grease then migrates along tissue planes and causes chemical damage that becomes visible as swelling, colour change, and infection over 24-72 hours. Go to an emergency department immediately for any suspected injection injury, brief the staff it is a high-pressure grease injection (not a simple puncture), and do not wait for pain to develop. Untreated grease injections can progress to tissue necrosis and amputation regardless of the pressure tier.

What PPE is required when using the S-735?

Mandatory: wraparound safety glasses (ANSI Z87.1+ impact-rated), nitrile chemical-resistant gloves, long sleeves, and closed-toe shoes at minimum. Safety rules: never point the coupler or flex hose at any body part, use both hands on the dual-lever handles during pumping rather than trying to one-hand the gun, inspect the hose and coupler before each use for visible damage, never test grease flow by pressing the coupler against skin or fabric. The dual-lever design intrinsically keeps both hands on the gun rather than one hand near the coupler, which provides a small additional safety margin over single-lever guns where operators sometimes hold the coupler with the non-lever hand.

How do I load an F-type threaded cartridge onto the S-735?

Take a fresh F-type vacuum-sealed cartridge, remove the protective cap, position the cartridge at the threaded port on the head, and thread it home until firmly seated against the head gasket. No barrel unscrewing is needed, no plunger retraction, no seal peeling, no priming. Once seated, grip one handle with each hand in the dual-lever position and squeeze: grease should flow on the first pump because the vacuum seal has kept the grease column in continuous contact with the pump chamber. If priming fails after 2-3 pumps, check that the cartridge is fully threaded home (not just finger-tight), and confirm the cartridge is within its shelf life (vacuum seals degrade in long-stored cartridges). Cartridge change typically takes under 20 seconds.

Is the S-735 suitable for automotive, tractor, and heavy industrial service?

Yes for automotive dealership service and light-to-medium industrial lubrication where F-type cartridges are stocked; marginal for heavy tractor and outdoor-exposed heavy equipment service where 12,000 PSI is sometimes needed to clear crusted zerks. For German and European automotive OEM service, factory maintenance, industrial conveyor service, machine-tool lubrication, preventive-maintenance programs on regularly-maintained equipment, and fast lube centre service, the 7,500 PSI pressure tier combined with the F-type cartridge supply makes the S-735 the correct pick. For mining haul trucks, broadacre farm tractors with crusted zerks, or outdoor construction equipment that sits between service cycles, step up to the heavy-duty standard-barrel range or wide-barrel range depending on the cartridge supply for the market. The S-735 is an industrial-service product, not a rough-yard heavy-equipment tool.

How should I store the S-735 between service cycles?

For storage under 30 days: leave an F-type cartridge threaded onto the head (the vacuum seal keeps grease fresh), cap the coupler, store horizontally in a clean dry area with the plunger disengaged. For storage over 30 days: unthread the cartridge and store separately, wipe the head's threaded port with a lint-free rag, cap the port with the supplied plastic cap, and store the gun horizontally in a clean dry shed. Cold-cycling the gun in utility-vehicle beds or outdoor locations accelerates oil separation from the grease and can compromise the vacuum seal on a threaded-on cartridge over time. Always store out of direct sunlight to prolong powder-coat and hose-rubber lifespan. The zinc-plated lever handles resist corrosion well but will still benefit from dry storage in humid climates.

Can the S-735 be rebuilt with standard STAR spare parts?

Partially. The head's F-type (or F&LS-type) cartridge port thread, the vacuum seal interface, and the dual-lever pivot assembly are specific to the S-735 architecture; the non-return valve, coupler, hose, and steel extension are common with other STAR lever guns. Rebuild kits for the S-735 are supplied from the STAR spare parts catalogue including the cartridge-port seal and the dual-lever pivot hardware. Typical wear-part lifespan at regular industrial service: cartridge port seal 3-5 years, non-return valve 5-8 years, hose and coupler 3-4 years, dual-lever pivot assembly 7-10 years. A full rebuild costs a fraction of a new gun and extends working life indefinitely; the minimal-wearing-parts design of the S-735 means rebuild intervals are typically longer than on 4-way loading guns of similar price.

Is the S-735 available for OEM and private-label orders to European and industrial distributors?

Yes. OEM and private-label manufacture is available on both the S-735 and S-735/LS for German, European, and wider industrial distributors including custom branding, packaging design for European industrial-supply format, BSPT/NPT/M10 thread variants, and kit configuration per agreement. MOQ depends on customisation level: product-level rebranding (logo and packaging only) has a lower MOQ than full thread or kit-spec customisation. Shipping is sea freight to Rotterdam, Hamburg, Antwerp, Bremerhaven, and other European hub ports for onward distribution. Mixed-container consolidation with other STAR products (specialty-cartridge S-733/S-734/S-739, standard-barrel lever guns, accessories) is possible to hit MOQ thresholds economically. Contact the STAR export team for European distributor pricing, lead times, and packaging specifications. Made in Ludhiana, Punjab, India, exported to 27+ countries since 1980.