Class and capacity
Compare attachment weight and moment with the load chart and actual configuration, not just machine operating weight.
Carrier-to-tool decision instrument
Tonnage class only filters candidates. Final compatibility requires attachment weight and moment, carrier capacity, flow, pressure, return/case drain, one- or two-way circuit, pin/coupler geometry, controls and stability.

Do not buy a breaker, grapple or shear only because the listing says “for a 20-ton excavator.” Obtain the attachment sheet and exact machine configuration, place both in one matrix and close every interface. One hydraulic, mechanical or stability mismatch is enough to stop the purchase.
Compare attachment weight and moment with the load chart and actual configuration, not just machine operating weight.
Required range must fit the configured auxiliary supply. Too much creates heat/speed; too little reduces performance.
Relief setting and working pressure must protect both machines. A maximum figure is not the recommended setting.
Some motors and breakers need low-back-pressure return or a separate drain. Omitting it can damage seals and housings.
Breakers commonly use one-way flow; grapples, shears and tiltrotators normally require two-way and possibly extra functions.
Diameter, centres and ear width must match bucket/coupler. Adapters change geometry and can affect force or safety.
Confirm type, primary/secondary lock, indication and attachment compatibility; test retention to the manual.
Weight at reach changes side/front capacity. Compare radius, height, blade, shoes, gauge and counterweight.
Material, duty cycle, temperature and shift hours determine wear and cooling; fitting does not mean lasting.
| Attachment | Common error | Better decision |
|---|---|---|
| Breaker | Selecting only by carrier tonnage and tool diameter. | Confirm energy/frequency, flow, pressure, return, back pressure, lubrication and rock duty. |
| Grapple | Ignoring rotation and a second function. | Separate open/close, rotation, drain and hose protection; confirm controls. |
| Shear/pulveriser | Underestimating weight and moment at reach. | Use load chart, demolition configuration, valves, rotation and guarding/structure. |
| Tiltrotator | Treating it as a simple quick coupler. | Check added weight, build height, hydraulic/electrical control, locking and compatible buckets. |
| Compactor | Looking only at plate width. | Verify weight, frequency, flow, pressure, return and slope-working limits. |
| Bucket | Copying width from a different material density. | Compare SAE volume, density, teeth, tip radius, digging force and stability. |
Published attachment settings show why flow, pressure and piping must be matched to the exact carrier configuration.
Published attachment settings show why flow, pressure and piping must be matched to the exact carrier configuration.
Published attachment settings show why flow, pressure and piping must be matched to the exact carrier configuration.
No. It is an initial filter. Confirm capacity, weight/moment, hydraulics, geometry, controls, stability and exact application.
Not always. A grapple normally needs bidirectional flow and rotation may need another circuit or drain. Check the schematic and valves.
Some excavators store presets, but a menu does not confirm line size, return, relief or cooling capacity. Verify the physical system.
It is a low-pressure line returning internal leakage from certain motors/components. When required by the maker it cannot be plugged or merged into an unsuitable return.
A competently designed adapter can solve geometry, but it adds weight/build height and changes kinematics. Recalculate force, locking and stability.
Coupling/locking, every function, flow/pressure, temperature, leaks, hose routing through full movement and stability in the intended scenario.
Published and reviewed: 19 August 2026 · YUANJIAN MACHINERY INTERNATIONAL TRADING LIMITED