BIZOMAT MAKEOS · Hydraulics
Hydraulic Hand Jack Check (Handle Leverage, Pump Pressure, Lifting Force, Strokes to Lift)
For a hand-pumped hydraulic jack or press, what pressure does the handle effort make, can it lift the load, and how many pump strokes does the lift take?
Check of a hand-operated hydraulic jack or press: the force on the pump plunger from the handle effort and lever arms (as the lever force tool), the pressure from the plunger area, the lifting force of the ram with an efficiency, the effort needed for the rated load, and the number of pump strokes to raise the ram by the lift height from the ratio of displaced volumes, against the load, the system pressure rating and a limit on strokes.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Handle effort | N | Force the operator applies at the end of the handle. |
| Handle length (pivot to hand) | mm | Distance from the handle pivot to the hand position. |
| Pivot to plunger | mm | Distance from the handle pivot to the plunger pin. |
| Pump plunger diameter | mm | Diameter of the pump plunger. |
| Ram diameter | mm | Diameter of the lifting ram. |
| Overall efficiency | % | Overall efficiency of the pump and ram (seal friction and leakage). |
| Duty | ||
| Load to lift | N | Load the jack must lift. |
| Pressure rating of the jack | MPa | Highest pressure the jack is rated for (relief valve setting). |
| Lift height | mm | Height the ram must rise. |
| Plunger stroke | mm | Stroke of the pump plunger per handle stroke. |
| Most strokes accepted | strokes | Most handle strokes acceptable for the lift. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Handle effort
- What it is
- The force the operator applies at the hand position on the end of the pump handle, at right angles to the handle.
- Units and format
- Enter a number in N: newtons. The form accepts 0.000001 N to 1000000 N. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 300 N as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Plunger force, pressure and lifting force rise in proportion to it.
- Get it right
- Base it on what an operator can apply in that posture from your manual handling guidance.
What this means: Handle length (pivot to hand)
- What it is
- The distance along the handle from its pivot to where the operator’s hand pushes, the long arm of the handle lever.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 500 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A longer handle raises the plunger force in proportion.
- Get it right
- Measure from the pivot pin centre to the middle of the grip, not to the end of the handle.
What this means: Pivot to plunger
- What it is
- The distance from the handle pivot to the pin that drives the pump plunger, the short arm of the handle lever.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 40 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A shorter distance raises the plunger force in proportion.
- Get it right
- Measure between pin centres; it must be shorter than the handle length.
What this means: Pump plunger diameter
- What it is
- The diameter of the small pump plunger that the handle drives to pressurise the oil.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 1000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 12 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A smaller plunger raises the pressure for the same handle force but needs more strokes.
- Get it right
- Measure the plunger itself, not its bore or seal groove.
What this means: Ram diameter
- What it is
- The diameter of the lifting ram that the oil pressure pushes up.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 10000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 40 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Lifting force rises with the square of the ram diameter, and so do the strokes needed.
- Get it right
- Use the ram diameter that the pressure acts on, not the outside of the cylinder.
What this means: Overall efficiency
- What it is
- The overall efficiency of the pump and ram: the share of the ideal hydraulic force that reaches the load after seal friction and leakage.
- Units and format
- Enter a number in %: percent: the number is read as a percentage, so type 8 for 8 %. The form accepts 10% to 100%. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 90% as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Lifting force rises in proportion to it.
- Get it right
- Type the percentage itself, not a fraction; take it from the jack maker or a test.
Duty
What this means: Load to lift
- What it is
- The load the jack must lift, compared with the lifting force and used to work out the pressure and handle effort it needs.
- Units and format
- Enter a number in N: newtons. The form accepts 0.000001 N or more. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 30000 N as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Enter it in newtons: multiply a mass in kg by 9.81.
What this means: Pressure rating of the jack
- What it is
- The highest pressure the jack is rated for, usually its relief valve setting, compared with the pressure needed to lift the load.
- Units and format
- Enter a number in MPa: megapascals (1 MPa = 1 N/mm²). The form accepts 0.000001 MPa to 1000 MPa. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 40 MPa as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Take it from the jack’s rating plate or manual; 1 bar = 0.1 MPa.
What this means: Lift height
- What it is
- The height the ram must rise to lift the load as far as needed.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 150 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Strokes needed rise in proportion to it.
- Get it right
- Measure ram travel, not the overall height of the jack.
What this means: Plunger stroke
- What it is
- The distance the pump plunger moves in one full handle stroke.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 10000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 20 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A longer plunger stroke lowers the number of strokes in proportion.
- Get it right
- Measure the plunger travel, not the movement at the end of the handle.
What this means: Most strokes accepted
- What it is
- The largest number of handle strokes you accept to raise the ram through the lift height.
- Units and format
- Enter a number in strokes: strokes. The form accepts 1 strokes to 1000000 strokes. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 100 strokes as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Get it right
- Set it from the task and how long the operator can pump; the tool does not suggest one.
Method and formulas
- Plunger force = effort × handle length ÷ pivot distance (as the lever force tool).
- Pressure p = plunger force ÷ (π d_p² ÷ 4); lifting force = p × π D_r² ÷ 4 × efficiency.
- Pressure for the load = W ÷ (π D_r² ÷ 4 × η); strokes = D_r² h ÷ (d_p² s_p), rounded up.
- Example: 33.157 MPa lifts 37.5 kN; 84 strokes raise it 150 mm.
Limitations
- Static balance; seal friction varies with pressure and is taken in the efficiency.
- Leakage past the check valves adds strokes.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Check a bottle jack or workshop press
- Choose plunger and ram sizes for a hand pump
- Find the handle effort for a given load
Who it is for
- Design engineers
- Maintenance fitters
- Engineering students
What you get
- Plunger force and pressure
- Lifting force and effort for the load
- Pressure and strokes for the lift
Interpreting the result
- The force multiplication is the lever ratio times the area ratio; the strokes needed grow with the same area ratio.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 167–168, 3024–3027. Topic reference; no source tables or recommended settings are reproduced.
BIZOMAT tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.