Shearex HM-70SV front-mount mulcher

Where the HM-70SV sits in the range

The HM-70SV is the first head in the Shearex HM front-mount mulcher range that is really intended for a dedicated mulching carrier rather than a conventional skid steer. It keeps the 190 cm cutting width of the HM-70 but lifts the minimum carrier power to 125 hp, the target diameter to 25 cm and the flow window to 178 to 288 L/min. Above it, the HM-88LV widens the swath to 220 cm on the same flow window and a 140 hp minimum. The HM-70SV is the choice for a contractor whose carrier has the hydraulic power for heavy vegetation but who wants a compact head width for transmission easements, pipeline corridors and firebreaks where the strip is narrow and the material is heavier than a loader head should see.

What the published figures mean on site

The 190 cm cutting width matches the HM-70, so the difference between the two heads is not swath but appetite. The optimal target material diameter of 25 cm is the stem size the rotor keeps processing at a productive rate, and it covers most regrowth eucalypt, wattle and pine understorey on an easement. Larger stems are occasional work, and pricing on them is how tenders go wrong; see maximum diameter versus production diameter.

At 1,655 kg the head is beyond what a conventional skid steer should carry on the front, and it belongs on a purpose-built carrier or the largest compact track loaders with the manufacturer’s blessing. Continuous flow of 178 to 288 L/min and the 125 hp minimum carrier power are the real qualifying tests, and the top of that window is a dedicated-carrier number.

Carrier matching

Carrier horsepower is the first filter, but the high-flow circuit rating is the deciding one. Ask for the circuit’s continuous L/min and bar, whether a case drain is fitted, the return pressure it imposes, the motor displacement the head will be built with, and how the cooling pack copes after an hour of continuous work with the screens loading up with fines in summer heat. If a large CTL is proposed, check the head’s 1,655 kg against its rated operating capacity and attachment guidance and expect the machine to be at the limit of its front-end stability. See hydraulic matching, hydraulic cooling and heat and the skid steer and track loader class page.

The published 125 hp minimum deserves a moment’s arithmetic, because it is a floor rather than a working figure. As an illustration only, 178 L/min at an assumed 300 bar is 178 × 300 ÷ 600, about 89 kW or roughly 119 hp, so a 125 hp carrier is already close to fully committed at the bottom of the flow window; the same assumed pressure at 288 L/min gives about 144 kW, or roughly 193 hp. Run the carrier’s own measured figures through the hydraulic power calculator before accepting a pairing.

Typical work and production considerations

The head fits powerline and transmission easements, mining and pipeline corridors and firebreak work in bushfire fuel reduction programs. Easement tracks, pipeline spoil and cuttings carry rock and buried debris that favour carbide teeth; blades cut faster and cleaner in clean green material but suffer on ground contact. See blades versus carbide teeth.

Limitations and when to step up or down a size

A front-mount head is limited to ground the carrier can traverse, so batters, drains and steep or wet corridors are excavator territory; excavator mulcher versus skid steer mulcher compares the two, and the VM-50SR is the excavator head with the same 25 cm target. Step down to the HM-70 if the carrier is a conventional loader and stems are under 20 cm. Step up to the HM-88LV for more width on the same hydraulics, or to the HM-90SV when 40 cm material is regular.

Options and hydraulic circuits to settle at quotation

There is a single HM-70SV variant, so the decisions at quotation are tooling, motor build for the carrier’s flow and pressure, the case drain and return arrangement, and the electrical control for the door on the carrier’s harness. Confirm the quoted weight is for the head as ordered with its mounting plate.

Wear parts and support

Heavier material means faster tooling consumption, so budget tool cost per hectare rather than per set and get Australian stock and pricing from Machinery Specialist before signing. Fines and dust load

Confirm before ordering

• Carrier meets 125 hp minimum and its high-flow circuit sits within 178 to 288 L/min continuously at pressure
• Case drain, return pressure and motor build matched to the carrier
• Head weight of 1,655 kg against the carrier's capacity and attachment guidance
• Cooling pack capacity and cleaning access for continuous summer work
• Blade or carbide tooling for the corridor's rock exposure
• Australian stock and price of teeth, holders, belt and bearings
• Delivered price including mounting plate, hoses and electrical harness

Frequently asked questions