Powerhand EX28 grapple saw

The model where the saw specification is actually chosen

The EX28 sits in the middle of Powerhand’s rigid grapple saw range, between the EX25 for 8 to 12 tonne carriers and the EX36 for 16 to 25 tonne machines. Its 12 to 25 tonne band covers the excavators most civil and vegetation contractors already own, which is why it is the model most often specified as a first grapple saw.

It is also the first head in the range where the saw itself is a set of decisions rather than a fixed package. The EX25 comes with one chain pitch and one sensible motor. The EX28 offers multiple saw motor displacements and a choice of 0.404 inch or 3/4 inch chain, and those two selections do more to set what the head costs to run than the carrier choice does. The grapple saw buying guide sets out the rigid, tiltrotator and tree-care architectures, and the EX25 vs EX28 vs EX36 vs EX40 comparison lines the sizes up.

For handling without cutting, the EX28 forestry grapple carries the same 0.28 m² capacity and 1,632 mm opening at 617 kg with rotator, against 986 kg here.

Choosing the saw motor displacement

A hydraulic saw motor converts flow into chain speed and pressure into cutting torque, and displacement is the exchange rate between them. A large-displacement motor gives more torque per unit of pressure but needs more litres per minute to reach a given chain speed; a small one spins up on modest flow but has less to give when the chain bogs in dense timber.

The mistake to avoid is ordering the largest motor on the list. Fitted to a carrier that cannot supply its flow, a big motor turns a slow chain, and a slow chain in hardwood cuts by rubbing rather than by clearing chip. That produces long cut times, heat in the oil and premature chain and bar wear, all of which look like a chain problem and are not. The opposite error is subtler: a small motor over-sped by generous flow reaches its speed limit, and the surplus energy goes into heat and into wearing the motor’s own bearings.

So measure before choosing. Get the carrier’s actual auxiliary flow and relief pressure at working engine speed, not the brochure figures, and have the supplier nominate a displacement against those measurements. Check the return line and cooling too, because a saw circuit run continuously on a hot Australian afternoon adds heat the carrier’s cooler was not sized for. The hydraulic matching guide covers flow and pressure, and hydraulic cooling and heat covers where that heat goes.

Choosing between 0.404 inch and 3/4 inch chain

Pitch is the distance between the chain’s drive links, and it sets how much steel is in the cutting system. The 0.404 inch chain is the lighter of the two: less mass to accelerate, faster to change, cheaper per loop, and entirely adequate for the council, corridor and storm work the EX28 spends most of its life doing. The 3/4 inch chain carries heavier cutters and links, resists the shock loading of large-diameter cuts and dirty bark better, and stays sharper longer under sustained load.

The trade is cost and inertia. A 3/4 inch system needs its own bar, its own drive sprocket and its own chains, it is dearer per loop, and it demands more of the motor to reach cutting speed. The decision rule is about consistency, not maximum size. If large-diameter hardwood is what the head does most days, 3/4 inch is the cheaper system over a year despite the higher unit cost. If the big cuts are occasional, 0.404 inch is the better buy and the occasional heavy cut is simply slower.

Price both systems before committing, because the pitch decision is difficult to reverse: changing it later means a new bar and sprocket as well as new chain. Ask for chain, bar and sprocket pricing in each pitch, and for the Australian stock position on both.

What 986 kg leaves for the timber

Cutting capacity and lifting capacity are unrelated figures, and the treatment of that point in full is on the EX25 page. The consequence specific to the EX28 is the spread inside its band. At 986 kg the head is roughly half as heavy again as the EX25, and on a 13 tonne carrier that deduction leaves little for the severed section at reach, while on a 22 tonne carrier the same head barely registers. The 12 to 25 tonne band is therefore a shortlist, not a recommendation: check the chart for the specific machine with the lift capacity calculator and the lift chart and attachment mass guide, and remember that Australian hardwood is at the dense end of what any chart assumes.

Typical work

The EX28 is at home in road corridor clearing and rail corridor vegetation, where possession windows and traffic control mean the machine must fell, section and stack in one cycle with nobody under the load. It suits subdivision and civil clearing where the carrier is already mobilised for earthworks, storm damage and dangerous trees, and biomass and chipper operations where it cross-cuts over-length material and then feeds it.

Size pieces to the chipper infeed and the stack layout rather than to the rated cut. The largest section is rarely the fastest, because placement time and carrier stability dominate the cycle far more than chain speed does.

Up a size, down a size, or a different tool

If the work sits consistently at 600 mm and above in hardwood and the carrier is 20 tonnes or more, the EX36 brings a 1,000 mm bar, a 650 mm cut and a 1,928 mm opening for another 190 kg. If the carrier is 12 or 13 tonnes and the timber is urban and modest, the EX25 preserves 335 kg of lift for very little lost capability. Where felling is repetitive small-stem work, a tree shear cycles faster with almost no consumables.

The architecture is a separate question again: the same EX28 head is built on a tiltrotator and in a tree-care worm-drive form, both of which differ in weight, hydraulic demand and control integration, so the architecture must appear in writing on every quotation.

Running costs

Chains, bars, drive sprockets, saw motor service and chain oil are the recurring spend on any grapple saw, and on the EX28 all of them move with the pitch chosen, which is why both systems should be priced before the choice is made rather than after. Track chains per day and bars per month from the first month so the tender rate reflects the real consumable burn; the wear parts guide gives a pricing checklist and building a tender rate shows where the figures go.

Confirm before ordering

• Measured auxiliary flow and relief pressure at working engine speed, not brochure figures
• Saw motor displacement nominated by the supplier against those measurements, in writing
• Return line size and cooling capacity checked for continuous sawing in summer heat
• Chain pitch chosen from how often large hardwood is actually cut, not from the largest job imagined
• Chain, bar and drive sprocket priced in both 0.404 inch and 3/4 inch before deciding
• 986 kg deducted from the chart of the specific carrier, not the 12 to 25 tonne band
• Architecture written on the quotation: rigid, tiltrotator or tree-care
• Automatic chain tensioning, lubrication reservoir and Australian parts stock confirmed

Frequently asked questions