OMEF · Stump shear

OMEF ST90

Name: OMEF ST90
Brand: OMEF

Mid-size stump shear for 12-20 t carriers — 900 mm opening, up to 70 t cylinder force.

4 published specificationsAustralian representation: Randalls

Positioning

Where this machine sits

The ST90 is a mid-size stump shear for 12-20 tonne carriers: 1,600 kg, a 900 mm opening and up to 70 tonnes of cylinder force. Shearing is a different approach to stumps from grinding — it splits and lifts the stump rather than reducing it to chips, which suits site preparation and stump recovery rather than finishing a lawn.

The carrier class is the decisive specification. At 1,600 kg the attachment has to be held at working reach on ground that is frequently uneven, and the lift chart with the shear fitted is what determines whether a carrier in the stated class can actually use it.

Published figures

Specifications

Indicative published manufacturer and distributor information. Confirm every figure, lift chart and hydraulic requirement with the manufacturer or authorised dealer before purchase.

Carrier class	12-20 t
Weight	1,600 kg
Opening	900 mm
Cylinder force	up to 70 t

Interpretation

What the published figures actually constrain

A specification table tells you what the machine is. This is what each of those numbers means for the work you would put it to.

Published figure	What it means commercially
12-20 t carrier class	A published guide, not a guarantee. Verify the specific carrier's lift chart with the 1,600 kg attachment fitted at the reach and angles the work uses.
900 mm opening	The stump size the shear can engage. Stump diameter at ground level rather than at breast height is the measurement that matters here.
Up to 70 t cylinder force	What splits the stump. Force determines how the shear performs in dense or well-rooted material, which is where shearing is hardest.
1,600 kg attachment weight	Mass that must be supported at reach, and that reduces the carrier's lift capability everywhere. It is the figure the lift-chart check starts from.

Before it fits

The four checks that decide whether your carrier can run this

Each of these can fail independently, and passing one says nothing about the others. Weight class alone is the weakest of the four and the one most often relied on.

Check	For this attachment
Mass the carrier must control at reach	1,600 kg plus rotator and coupler, on a 12-20 t carrier. At the lower end of that class the chart runs out before the shear does.
Continuous hydraulic flow	Confirm the carrier's auxiliary circuit sustains the shear's requirement through repeated cycles, not just once.
Working pressure	Up to 70 t of cylinder force depends on the carrier delivering the specified pressure in service.
Cooling under sustained load	Shearing is intermittent rather than continuous duty, so cooling is less critical here than on a mulcher — but confirm it for sustained production days.

Commercial fit

Where this machine earns its cost

Right machine when

Plantation conversion and re-establishment where root mass must come out
Sites with a biomass destination for extracted stump material
Carriers genuinely in the 12-20 t class with the counterweight to work at reach

Wrong machine when

Urban finish work — stump shears are poor where excavation must be minimised
Stump populations above the 900 mm opening, where the ST140 is the correct size

Before you sign

Verify these for this specific model

Beyond the standard buying criteria for the class, these are the questions this machine in particular raises.

Stump diameter distribution including root collar, against the 900 mm opening
Soil type — heavy clay and rock change the extraction force required
Site rehabilitation cost after root removal, which belongs in the quote

Running cost

What drives the cost of owning this machine

Shearing suits stump recovery and site preparation, where the objective is removing stumps across an area rather than finishing individual ones. Where the material has a biomass outlet, recovery can offset part of the cost — but stumps carry soil, which affects both wear and specification compliance.

Carrier utilisation is the commercial advantage of an attachment-based approach. The 12-20 tonne carrier earns in other work when stump removal is not running, which spreads its fixed cost far wider than a dedicated machine achieves.

Wear on shear blades and pivots scales with material and with soil contact. Rocky or gravelly ground is hard on the attachment in ways that a clean demonstration does not reveal.

In practice

Ownership considerations in Australian conditions

Run the lift chart before trusting the carrier class

A published carrier class is a guide. The real check is the chart with 1,600 kg fitted at the reach and slew the work requires, on the ground conditions you will meet.

Match the opening to ground-level diameter

Stumps flare at the base. Measuring at breast height or from the standing tree understates what the shear has to engage.

Confirm hydraulic requirements with the carrier

Flow and pressure have to be met by the carrier's auxiliary circuit continuously. This is a separate check from the lift chart, and both have to pass.

Questions

Common questions about this machine

Stump shear or stump grinder?

They solve different problems. A shear splits and lifts the stump, which suits site preparation and stump recovery across an area; a grinder reduces it to chips in place, which suits finishing individual stumps where the ground has to be usable afterwards. Neither substitutes for the other, and the stump systems chapter sets out where each is the honest choice.

Can a 12 tonne excavator really run this attachment?

The published class says it is within range; the lift chart says whether it is within range for your work. A 1,600 kg attachment reduces lifting capability everywhere and has to be controlled at reach on uneven ground. Run the chart with the shear fitted at the reach and slew angles the job needs before accepting the class figure.

Does stump material have any resale value?

Sometimes, as biomass — but stumps carry soil, which accelerates wear in any processor and can push a load outside a buyer's contamination specification. Recovery generally makes sense where a grinder is already in the fleet, the buyer tolerates the material, and the stumps had to be removed anyway. It rarely justifies the removal on its own.

Same class

Alternatives to compare against

Other stump shears covered in this guide.

OMEF

ST140

Heavy stump shear for 20-35 t carriers — 1,400 mm opening, up to 90 t cylinder force.

In service

Fleet packages that use this class

Package D

Commercial land clearing

A deliberately flexible attachment-based system. Instead of owning six specialised purpose-built forestry machines, the same base excavator generates revenue across civil earthworks, demolition, vegetation clearing, log handling, tree removal, stump removal, road construction and drainage.

Package G

Plantation re-establishment

A sequence rather than a machine: stump treatment, then slash treatment, then tillage, scarification or mounding, then planting. Measured in hectares and planting spots, not cubic metres.