Application · CNC
A CNC machine leans on hydraulics to hold the work: the chuck grips the part, the tailstock supports it, and fixture clamps locate it — and every one of those has to stay put while the machine cuts. A CNC power pack has to actuate those circuits and then hold their pressure steady, from a compact, continuous-duty unit that runs reliably all shift and keeps its oil clean. This page sets out what CNC chuck, tailstock and clamping duty asks of a hydraulic power pack, the typical requirements, and the right Suyog unit for the job.
On a CNC lathe or turning centre the hydraulics typically drive three things: the chuck that grips the rotating part, the tailstock quill that supports long work, and any fixture or workholding clamps on the machine. Some machines add a tool-turret clamp or a steady-rest. Each of these is an actuation-and-hold job — the circuit strokes briefly to grip or clamp, then must hold that force without loss while the spindle runs and the tool cuts.
The holding is what makes CNC workholding demanding. The chuck grips a part turning at speed; if clamp pressure drifts, grip force falls and the part can slip — scrapping the job and creating a real safety hazard. So while flow demand is modest (the strokes are short) and the pump does not run continuously under load, the pack must deliver a steady, drift-free holding pressure, be compact enough to sit by the machine, and run reliably shift after shift.
The figures below are typical, illustrative ranges for CNC chuck, tailstock and fixture actuation — a starting point, not a specification. Your actual pressure follows from the gripping or clamping force each circuit needs and the bore that produces it (see the selection method).
| Parameter | Typical / illustrative range | Why |
|---|---|---|
| Working pressure | 40–160 bar (typical) | Set by grip/clamp force ÷ bore; many chucks & fixtures run ~100–150 bar. |
| Flow | Modest — a few L/min (typical) | Chuck, tailstock and clamp strokes are short; flow only sets actuation speed. |
| Reservoir | Compact tank (typical) | Low flow and intermittent load keep the tank — and footprint — small. |
| Control | Solenoid (DCV) per circuit | Chuck / tailstock / clamp switched from the CNC control; closed-centre to hold. |
| Relief / safety | Working pressure + ~15–20% | Protects chuck, fixture and pack; caps peak pressure. |
| Duty | Continuous-rated, intermittent load | Runs all shift; pump loads only to grip/clamp, then holds. |
Ranges are typical and illustrative only. Final values come from your gripping force, bore, number of circuits and duty cycle.
These Suyog units suit CNC chuck, tailstock and fixture clamping duty. General sizing guidance is separate — the guides below cover the engineering; these are the products we build for the job.
Compact clamping unit built around steady holding pressure — suits CNC fixture and chuck circuits too.
View product →Multi-circuit power units for CNC chuck, tailstock and clamping actuation.
View product →Proven standard HPUs where a catalogue unit fits the actuation duty.
View product →Built to your chuck, tailstock, pressure, control and space envelope when the standard range doesn’t fit.
View product →These are general engineering references — use them to work out your own numbers before matching them to a Suyog unit.
The full step-by-step method from application to specified unit.
Read guide →Why pressure sets grip force and flow sets actuation speed — independently.
Read guide →Turning working pressure and flow into the right motor kW.
Read guide →Run pressure, flow and motor-power numbers for your CNC circuits.
Open calculators →CNC chuck, tailstock and fixture actuation typically works in a roughly 40 to 160 bar range, with many hydraulic chucks and clamping fixtures specified around 100 to 150 bar (typical, illustrative figures). The exact pressure follows from the gripping or clamping force required and the chuck cylinder or clamp bore that delivers it — pressure equals force divided by piston area. Set the working pressure at the required figure plus about 20% margin and round up to a standard rating shared by the pump, valves and gauge.
Yes. Give us the gripping or clamping force, the working pressure your chuck cylinder, tailstock or fixture is rated for, how many circuits act and in what sequence, and the control interface. We size the pump, motor, reservoir and manifold to those figures and match port sizes, voltage and mounting so the unit fits your machine. Keep the general sizing method separate — that is engineering guidance; matching a built unit to your machine is what we do.
On a turning centre the chuck grips the rotating part throughout the cut, so any loss of clamp pressure lets grip force fall — risking the part slipping at speed, which scraps the job and is a safety hazard. A closed-centre directional valve and a load-holding or pilot-operated check circuit keep grip pressure constant with no drift while the pump idles or unloads. Steady, drift-free holding pressure is the defining requirement for CNC workholding hydraulics.
Often yes. A single compact unit can supply several circuits — chuck, tailstock and a fixture clamp — each with its own solenoid directional valve, provided they share a working-pressure range and the combined flow stays modest, as it usually does for actuation. Where circuits need different pressures or must sequence, we add the appropriate valving. Tell us the circuits, their pressures and how they interact and we will lay out a single manifold to suit.
Machining on a VMC rather than turning? See Hydraulic Power Packs for VMC Machines, focused on fixture and workholding clamping for vertical machining centres.
Tell us about your CNC
Use the configurator for a full recommended configuration, or send your requirement and our engineers will match a unit to your chuck, tailstock and fixture.
