Mechanical vs Hydraulic Press: Force Curve, Speed and Control

Home / Blog / Mechanical vs Hydraulic Press

The Short Answer

A mechanical press delivers its full rated force only near the bottom of its stroke; a hydraulic press works to a set cylinder pressure through its stroke, under the fixed-stroke and fixed-pressure processes its tables publish. Their speeds are also published in different units — strokes per minute on the crank side, mm/s on the hydraulic side. The sections below compare the two on force, speed, control, energy and maintenance. This comparison uses the published data of one manufacturer's two ranges so the numbers are real: crank presses from 15 to 1,600 tons with SPM from 10 (the M1N-800 figure — a presumed restoration of a cell the manufacturer's table prints as a date) to 200, against hydraulic presses from 200 to 16,000 kN with descent speeds of 300 mm/s and working speeds of 15-80 mm/s on the pillar and C-frame tables.

Force: Where in the Stroke Can You Use It?

A crank press's force rises as the slide approaches bottom dead centre; the datasheet states a rated tonnage point — 3.2 mm above BDC on a C1N-45 V variant, 12-13 mm on an S2N-1600 (the model's two published configurations) — and full force exists only from that point down. A hydraulic press is not bound to that curve: its force comes from cylinder pressure, and its published processes are fixed stroke and fixed pressure. Drawing, forming and pressing work is documented among the hydraulic range's own applications — the Y1P page lists stretching, bending, flanging, cold extrusion, blanking, correction, pressing and powder compaction. Servo presses sit between: the EM2 page documents full working energy even at slow speeds, with a programmable profile — while still publishing a nominal pressure stroke (4-8 mm) for full nominal force.

Speed and Cycle Shape

Mechanical: 12 SPM on the largest eccentric press (likewise a presumed restoration of a date-printed cell in the S2N table), 20-200 SPM across the C-frame crank range, and high-speed derivatives to 2,000 SPM on the GT-15H. The working zone is crossed at whatever speed the crank geometry gives. Hydraulic: descent (fast approach) at 300 mm/s, work at 15-80 mm/s on the Y1P/Y1C tables (220-260 mm/s on the Y1H), return at 220 mm/s on the Y1P/Y1C. The two speed systems are stated in different units and are not interchangeable: a blanking rate in SPM belongs to the crank side of the comparison, and a hydraulic selection is made on its mm/s working speeds and its published nominal force. At the other extreme, a very deep draw — say 600 mm — needs force sustained through a long working zone, which a standard crank press's curve cannot give; note the judgement is about the force curve, energy and forming steps, not depth alone: this manufacturer's own S2N eccentric series is documented for deep-formed parts on transfer systems, so a long-stroke eccentric or a servo profile can be the right answer where a standard crank is not. Most real choices live between those cliffs, which is where the next factors come in.

Control: Stroke, Pressure, Dwell

• Mechanical — stroke is fixed by the crank (adjustable only by changing the machine setup or model variant); force is whatever the curve gives. The stroke repeats identically every cycle; the precision grade published for each series is stated in its own table.
• Hydraulic — stroke and pressure are both settable; this range offers fixed-stroke and fixed-pressure processes switched on the panel, with PLC control; the pillar and H-frame series document a pressure holding delay function.
• Servo (the third option) — the slide motion profile is programmable; the motion is set in software, not by the crank geometry.

Energy and Running Cost

A crank press spins its flywheel continuously and draws peak power in pulses. The servo comparison is documented on the EC1 page: energy saving of 50% or more claimed against a conventional press. Where the servo profile earns its place is mixed work with profile-sensitive parts, whose forming curve the programmable motion can follow.

Maintenance and Failure Modes

Mechanical wear concentrates in the clutch/brake, crank bearings and gibs — visible, schedulable, and protected here by forced lubrication with monitoring and hydraulic overload protection that stops the press before an overload damages the die. Hydraulic wear concentrates in seals, valves and oil condition; the Y1P/Y1C/Y1H range uses a cartridge-valve integrated hydraulic design, and there is no clutch to wear. Neither is maintenance-free; they simply fail differently, and a buyer's existing maintenance skills are a legitimate selection factor.

Both ranges are quoted the same way — send the part and the process. The sections above compare the two on force curve, control, energy and maintenance; the tables on the mechanical and hydraulic pages let you pre-check all four against your part before the enquiry.

Frequently Asked Questions

Which is cheaper, mechanical or hydraulic?

The published data supports no general price ranking between the two types: each machine is quoted on its own specification. The honest comparison is the one run on your own figures — cost per good part at your volume, including die life.

Can a hydraulic press do blanking?

It can punch and blank, and C-frame hydraulics are sold for it; the pillar and C-frame series publish working speeds of 15-80 mm/s, stated in mm/s rather than parts per minute. Whether a hydraulic press fits a given blanking job is read from its published working speed against the rate the job needs.

What about accuracy and repeatability?

Mechanical presses repeat by kinematics — the same stroke every cycle — and the C1N, C1S, D1N and M1N tables in this range state GB (JIS) Class 1 precision. Hydraulic presses repeat by control: fixed-stroke or fixed-pressure processes with PLC control. For shut-height-critical work, state the tolerance in the enquiry.

Where are servo presses documented to fit?

The EC1 and EM2 pages list suitability for high-tensile strength steel products, and document programmable motion profiles, set in software rather than by the crank geometry. Which drive fits a given part is read from those published profiles against the part's forming requirements. The EC1/EM2 tables are on the servo page.