Choosing the right workshop press — 20, 30, 50 or 100 tonnes?

A workshop press is a frame, a table and a hydraulic cylinder pushing down towards the table. The pump builds pressure in the oil, the cylinder turns it into force. That is all. But it is force enough to press bearings, bushings, shafts and pins in and out, straighten bent parts, and bend tube — jobs otherwise done with a sledgehammer and ruined parts.

Tonnes is the largest force the cylinder can give. It is not the force you use daily; most jobs take a fraction. The number says how much margin you have.

Stroke is how far the cylinder can travel in one pumping. To push a long shaft out of a hub the stroke must be long enough — otherwise you stop, pack underneath, and pump again.

Working height is the distance from the table to the cylinder. The table moves in fixed steps (six on all our presses), so minimum and maximum height say what fits.

Table width says how large a part fits between the frame legs. A hub bearing is small. A rear axle is not.

Two-stage pump is on every Mammuth press: the first stage moves the cylinder quickly down to the part, the second gives small, controlled movements at full force. It is the difference between pumping twenty times to reach the part, and pumping twice.

Pressure gauge shows what the job actually needs. If the needle heads for the top on a job that should be easy, something is sitting crooked — stop and check, instead of pressing harder.

There is no table that says "wheel bearing = so many tonnes". The force depends on fit, size, corrosion and whether the part sits straight — and corrosion is the great unknown. A wheel bearing on a new car comes out with a few tonnes. The same bearing after fifteen salted winters can easily take 40–50 tonnes. Nobody sees the difference until the press is on it.

So the rule is simple: choose the press by the heaviest job you can imagine, with margin — not by the most common one. A press working at half force gives control and a long life. A press worked to its maximum gives neither, and a job it cannot do stays undone.

What separates our presses is therefore not first of all which vehicles they suit, but how much margin you buy, and how large a part fits:

20 tonnes (SP20XH, SP20XHM) — compact, hand pump, 540 mm table. For the workshop that uses the press now and then, and sends the heavy jobs elsewhere.

30 tonnes (SP30XHAM, SP30HAMB) — air-hydraulic with foot pedal. Same table width as the 20-tonner, or 750 mm on the HAMB model. For the workshop that uses the press every day and wants its hands free.

50 tonnes (SP50XHM) — hand pump, 750 mm table. The margin that takes the rusted bearing, heavy axles and straightening bent parts, which takes far more than pressing a bearing.

100 tonnes (SP100XHAM) — air-hydraulic with foot pedal, 850 mm table, 300 mm stroke. For large bearings, press fits in steel and straightening thick sections.

All the Mammuth presses have a hydraulic cylinder. The difference is what drives the pump.

Hand pump (SP20XH, SP20XHM, SP50XHM): you pump with a lever. Simple, no connection, works anywhere. The drawback is that one hand pumps while the other holds the part — and a heavy job takes many strokes. For the press used a few times a week, that is perfectly fine.

Air-hydraulic with foot pedal (SP30XHAM, SP30HAMB, SP100XHAM): compressed air from the compressor (8–12 bar) drives the pump, and you control it with your foot. Both hands are free to hold the part straight and feel when it seats. It is safer and faster, and that is why the busy workshops choose it. The hand pump is still there as a backup if the air is off.

Side-adjustable cylinder. On all our presses except the SP20XH the cylinder slides sideways along a scale. So you move the cylinder to the part, instead of balancing the part under the cylinder. On awkward parts it is the difference between hit and miss.

A table that is easy to move. A press table is heavy. The 50- and 100-tonners have a crank or hand wheel, the SP30HAMB a winch: you put the part on the lowest step and wind the table up to working height. Without it you lift the table yourself.

Interchangeable press head. All our presses have it. You mount press pins, drifts and accessories straight on the cylinder instead of stacking loose pieces in between.

Press blocks and V-block. Included. The V-block keeps round stock centred; the press blocks give a face to press against without damaging the table.

Fully welded frame. A bolted frame gives and twists under load. All the Mammuth presses are fully welded, and that is why they stand up to straightening work.

A press requires the part to come to the press. Much of it does not: a bearing in a machine bolted to the floor, a shaft in a frame, something that has to lift a few millimetres to get the shim under. Then you turn it around and bring the force to the part.

Mammuth’s flat cylinders are hydraulic cylinders low enough to get into tight spaces — from 47 mm tall on the 10-tonner to 100 mm on the 200-tonner. They are driven by a separate 700-bar pump through a hose, and the piston is chromed and retracts by itself when the pressure is released.

There are two kinds: single cylinders have a short stroke (11–18 mm) and the lowest height. They are for jobs where the part only has to move a little: lift, clamp, push a bushing out a few millimetres. Double cylinders (the D versions) have a longer stroke, 25–75 mm, and are almost as low when collapsed. Choose double when the part has to move more than a couple of centimetres.

The force is chosen as for the press: with margin. And because the cylinder often sits under something heavy, the same rule as for jacks applies: the cylinder lifts, it does not hold. Secure the load with a stand or block before anyone goes under.

To be honest: the pump that drives them is not in our catalogue today. If you need cylinder and pump together, ask us and we will put a set together.

The part must sit straight. The most common press accident is a part that sits crooked, builds up force, and lets go. Centre it under the cylinder, use the V-block on round stock, and watch the gauge: if it climbs fast on an easy job, something is wrong.

Safety glasses, always. Hardened steel that fails under press fails in pieces.

Not above maximum. If the part will not move, the press is not what needs pushing harder. Check the setup, use heat or a puller, or a larger press.

Do not leave the part under pressure. Release the pressure when you leave the press. A cylinder can creep, and a part under load is a part that can go.

Oil and air. The hand pumps use OKCH68 hydraulic oil; keep the level up. Air-hydraulic presses want dry, clean air at 8–12 bar — a water separator on the line saves the pump.

Headroom. The table goes up to 958 mm on the 20-tonner and the frame is tall. Measure before you order, especially under low ceilings.