Pfaff-Silberblau JH Universal Hydraulic Jack

Model JH | Capacity 2 t – 50 t | Hydraulic Bottle Jack | Single-Stage Pump (Two-Stage on JH-50-2) | Pressure Relief Valve | Controlled Lowering | CE & UKCA Marked | Made in Germany

The Pfaff-Silberblau JH is the universal hydraulic bottle jack for workshop, plant and on-site lifting, with eight capacity grades from 2-tonne workshop work through to 50-tonne heavy machinery moves. All share the same robust format: vertical cylinder body, hand-lever-operated pump, pressure relief valve for overload protection, controlled descent via a release valve, and a grooved top saddle that grips the load against rotation. Models from 2 t to 20 t add a screw extension on the piston for fine-height adjustment without further pumping, and every jack ships with its operating lever ready for use.

Key Features

• Pressure relief valve: Integral overload protection prevents over-pressurisation of the hydraulic circuit and protects the operator if an attempt is made to exceed the rated capacity.
• Controlled lowering via release valve: Smooth, operator-controlled descent at any chosen rate by graduated release-valve opening — the load does not drop freely.
• Screw extension on models up to 20 t: Threaded piston extension on the JH-2 B through JH-20 B allows fine height adjustment without further pumping — useful for setting the saddle to the load before applying hydraulic force.
• Two-stage pump on the JH-50-2: The 50-tonne model uses a two-stage pump for faster lift speed during the low-load portion of the stroke, automatically dropping into single-stage high-pressure mode for the final lift.
• Grooved top saddle: Knurled saddle face grips the load against rotation during lifting, preventing slip on smooth load surfaces.
• Large base plate: Wide, flat base on every model gives stability on workshop floors, plant surfaces, and prepared site standings.
• Single-piece cast cylinder body: Robust construction designed for daily industrial duty cycles.
• Operating lever supplied: Each jack ships with its matched operating lever — no separate accessory required.

Technical Specifications

Maximum lift heights include the screw extension where fitted. The JH-50-2 is the only model with a two-stage pump, providing faster initial-stroke speed under light load before slowing for the high-pressure final lift. The JH-30 and JH-50-2 omit the screw extension to keep their physical dimensions compact at the higher capacities.

More About This Product

The Pfaff-Silberblau JH is the universal hydraulic bottle jack for workshop, plant, and on-site lifting where a compact, high-capacity vertical jack is required. Eight capacity grades cover everything from 2-tonne workshop work through to 50-tonne heavy machinery moves, all sharing the same robust bottle-jack format: a vertical cylinder body with hand-lever-operated single-stage pump (two-stage on the 50-tonne model), pressure relief valve for overload protection, controlled descent via a release valve, and a grooved top saddle that grips the load against rotation. Models from 2 t up to 20 t include an additional screw extension on the piston for fine-height adjustment without further pumping; the JH-30 and JH-50-2 omit the screw to keep the higher-capacity bodies compact. A large base plate on every model provides stability on workshop floors and prepared site surfaces, and each jack is supplied with its operating lever ready for use.

Suitable Applications

The Pfaff-Silberblau JH range is the standard workshop and site hydraulic jack across vehicle workshops, plant maintenance, structural steelwork erection, machinery installation and removal, heavy load shifting, and on-site engineering. Light JH-2 B and JH-4 B models suit vehicle and trailer lifting, light plant maintenance, and general workshop use. Mid-range JH-6 B through JH-20 B cover machinery installation, structural steel positioning, and heavy plant maintenance. The high-capacity JH-30 and JH-50-2 are specified for heavy industrial machinery moves, generator and transformer positioning, and bridge bearing replacements. For applications requiring engagement of loads at floor level via a toe / claw foot — for example heavy machinery moves where the saddle cannot get under the load — see the Pfaff-Silberblau MH machine lifting jack range.

How to Use the Pfaff-Silberblau JH Hydraulic Jack

1. Verify capacity: Confirm the load weight is within the rated capacity of the jack. Never attempt to lift a load that exceeds the rated capacity stamped on the cylinder body.
2. Prepare the standing surface: Position the jack on a level, hard, clean surface capable of supporting the load reaction force. Soft ground, gravel, and uneven concrete are not suitable.
3. Position under a designated lift point: Place the jack saddle under a structural lift point on the load — never against thin sheet metal, plastic panels, or non-load-bearing surfaces.
4. Set the screw extension if needed (models up to 20 t): If the load is above the jack saddle, rotate the screw extension up to take up the gap before pumping. This conserves hydraulic stroke for the actual lift.
5. Close the release valve: Turn the release valve clockwise to fully closed before pumping.
6. Pump the lever: Operate the lever in smooth, full strokes to raise the load. Avoid short jerky strokes.
7. Place supports before working under the load: Once raised, immediately place axle stands, blocks, or other approved supports under the load. Never work under a load supported by the jack alone — a hydraulic seal failure or release-valve drift can drop the load without warning.
8. Lower the load: Verify the area beneath is clear, then slowly rotate the release valve anti-clockwise to lower at a controlled rate. Faster opening gives faster descent.
9. Stow the jack: Fully retract the piston and screw extension before storage. Keep the jack vertical to retain hydraulic oil in the reservoir.

Warning:
Hydraulic jacks are lifting devices, not load-holding devices. Always transfer the load to dedicated supports (axle stands, cribbing, or rated blocks) before working underneath. Never exceed the rated capacity. Never use a jack with visible oil leaks, damaged saddle, or distorted base. The jack is for vertical lifting only — horizontal or inverted use is not permitted unless explicitly stated on the unit.

Safety Information

• Always position on a level, hard, clean surface capable of supporting the reaction force.
• Never exceed the rated capacity stamped on the cylinder body.
• Use only at the designated lift points on the load — never against thin panels or non-structural surfaces.
• Transfer the load to dedicated supports immediately after lifting. Never work under a load supported by the jack alone.
• Inspect for hydraulic oil leaks before every use — even small leaks indicate seal wear and require service before the jack is returned to duty.
• Use the jack vertically only. Horizontal or inverted operation is not permitted unless explicitly stated by the manufacturer.
• Operate the release valve smoothly — sudden full opening can cause the load to descend uncontrolled.
• Workplace operators must establish a Thorough Examination regime under LOLER 1998 / PUWER 1998 appropriate to the duty cycle, typically at intervals not exceeding 12 months.
• Top up only with the hydraulic oil grade specified in the OEM manual — incorrect oils cause seal failure.

Inspection and Maintenance

The JH is built for long service with minimal maintenance, but routine inspection is essential. Before each use, check for oil leaks at the cylinder seal, ram, and reservoir; verify the saddle is undamaged and the screw extension threads (where fitted) are clean and undamaged. Periodically top up the hydraulic oil to the level marked on the reservoir — use only the oil grade specified in the OEM manual. The release valve should rotate smoothly and seal cleanly when closed; stiffness or leak-by indicates internal wear. Air can enter the hydraulic circuit if the jack is laid on its side for extended periods; bleed any trapped air by operating the lever with the release valve open before returning to service. The JH-8B has a model-specific spare parts list available (see Downloads); for other models, consult the family datasheet or contact our service team. WOLFF Onsite provides hydraulic jack servicing, Thorough Examination, and spare parts for the full Pfaff-Silberblau range.

Optional Accessories

• Replacement operating levers: Direct-fit replacement levers for each model in the JH range.
• Hydraulic oil: Manufacturer-specified hydraulic oil for topping up or fluid replacement during service.
• Saddle adapters: Custom load-distribution adapters for use against soft or curved surfaces.
• JH-8B spare parts kit: Service kit referencing the JH-8B-specific spare parts list (see Downloads).

Downloads

• Pfaff-Silberblau JH Datasheet (EN, 2024) — full spec table and dimensional drawings for all 8 models (PDF)
• Pfaff-Silberblau JH-8B Spare Parts List (EN / DE) — model-specific spare parts reference for the 8-tonne jack (PDF)

Frequently Asked Questions