OMEF · Tree shear

OMEF Big Inch BI500

Name: OMEF Big Inch BI500
Brand: OMEF

1,810 kg shear for 23-30 t excavators with 600 mm published maximum cut.

4 published specificationsAustralian representation: Randalls

Positioning

Where this machine sits

The BI500 moves to 1,810 kg on 23-30 tonne excavators with a 600 mm published maximum cut. That is a substantial step: the attachment weighs more than four times the BI300 and requires a carrier roughly three times the size, which makes it a different commercial proposition rather than a larger version of the same one.

At this scale the lift-chart question becomes the whole decision. A 1,810 kg attachment reduces the carrier's lifting capability everywhere, and the material the shear can cut is heavy enough that the boom, not the blade, is almost always the binding constraint.

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	23-30 t
Weight	1,810 kg
Maximum published cut	600 mm
Australian distributor	Randalls

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
23-30 t carrier class, 1,810 kg attachment	A serious mass to control at reach. The published class is a starting point; the chart with the attachment fitted is the check that matters.
600 mm published maximum cut	Severing capacity. A long 600 mm green hardwood stem is a significant weight at reach, and holding it safely is a different question from cutting it.
Step up from the BI300	Four times the attachment mass and roughly three times the carrier. The whole combination's capital and transport cost change, not just the attachment's.
Randalls Australian distribution	Local support for blades, pivots and service. At this duty level wear parts are a recurring cost worth confirming availability for.

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	1,810 kg plus rotator and coupler, on a 23-30 t excavator — over four times the BI300's attachment mass.
Continuous hydraulic flow	Confirm the carrier's continuous auxiliary rating covers repeated cutting cycles at working speed.
Working pressure	Verify the pressure held at that flow, since cutting force depends on both.
What usually binds first	The lift chart. A long 600 mm green hardwood stem at reach is a significant weight, and holding it is a separate question from severing it.

Commercial fit

Where this machine earns its cost

Right machine when

Commercial land clearing on a 25-30 t carrier that also runs a grapple, mulcher and stump shear
Larger regrowth and farm clearing where 300 mm-class shears are at their limit

Wrong machine when

The dominant stem class is well under 300 mm — the extra 1,390 kg over a BI300 costs boom payload for nothing
The carrier cannot hold the stem safely at full reach with 1,810 kg fitted

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.

Hardwood versus softwood figures — confirm which the 600 mm applies to
Continuous hydraulic flow and pressure available at the attachment
Lift chart at working radius with attachment, rotator and coupler fitted

Running cost

What drives the cost of owning this machine

The carrier requirement is the dominant cost. A 23-30 tonne excavator is a larger capital, transport and operating commitment than a 10 tonne machine, and that comparison belongs alongside the attachment rather than after it.

Larger carriers retain the cross-industry earning advantage of the attachment-based approach — civil, demolition and log handling all use machines in this class — so utilisation remains the commercial argument.

Blade, pivot and cylinder wear scale with material size and density. Larger material works the attachment harder, and maintenance rather than production is where that shows up.

In practice

Ownership considerations in Australian conditions

The lift chart is the specification

Deduct attachment, rotator and coupler weight and run the chart at the reach and slew the work requires. This is the calculation that prevents the failure mode attachment-based clearing most needs to avoid.

Confirm the auxiliary circuit sustains the demand

Flow and pressure must be met continuously. Verify the carrier's continuous ratings rather than peak figures.

Compare the whole combination, not the attachment

Stepping up the shear steps up the carrier. Compare total capital, transport and operating cost against the smaller combination before deciding.

Questions

Common questions about this machine

Why does a bigger shear need such a much bigger carrier?

Two reasons compound. The attachment itself is four times the mass of the small shear, which reduces lifting capability throughout the chart before any material is picked up. And the material it can cut is far heavier, so the carrier must hold substantially more at reach. Both effects push the carrier requirement up faster than the cutting capacity rises.

How do I know whether my excavator can run this?

Run the lift chart with attachment, rotator and coupler weight deducted, at the reach and slew angle your work actually uses, and compare it against the weight of green material at the sizes you will handle. Then separately confirm the auxiliary circuit's continuous flow and pressure. Operating weight class alone is the weakest of these checks and the one most often relied on.

Is it worth stepping up from the smaller shear?

Only if the material regularly exceeds the smaller shear's capability, and the carrier you would need is one you can keep busy. Because the step changes the carrier as well as the attachment, the honest comparison is between two complete combinations — and the smaller one usually wins on utilisation unless large material is a routine part of the work.

Same class

Alternatives to compare against

Other tree shears covered in this guide.

OMEF

Big Inch BI300

420 kg shear for 8-14 t excavators, 300 mm published maximum cut — the regrowth and fence-line workhorse.

OMEF

Big Inch BI600

2,400 kg shear for 30 t+ carriers needing ~250-300 L/min — a different category from compact shears.

TMK

TMK 300

310 kg shear for 6-20 t excavators — 250 mm hardwood, 300 mm softwood, and the difference matters.

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.