Why do my loppers crush branches instead of making a clean cut?

Start by considering three possibilities: the branch may exceed the loppers’ stated capacity, the tool’s design may not suit the cut, or the cutting parts may need attention. A blunt or misused pruning blade can make cutting difficult and damage pruning cuts. Some damage may be too severe for home correction, in which case a tool workshop can assess or sharpen the tool. [S1]

A crushed cut alone does not tell you which explanation applies. Check the instructions for your specific lopper model before trying again.

Find the model’s stated cutting capacity in its instructions or markings, then compare it with the branch at the intended cut. If you cannot find or confirm the capacity, do not guess: consult the maker’s instructions or ask the maker for guidance. The supplied sharpening advice also cautions that suitability and capacity should be checked for the specific lopper and branch. [S1]

If the branch is beyond the stated capacity, choose a tool whose instructions cover the job. If it is within capacity but the cut still crushes, consider the tool’s design and condition rather than assuming capacity is the only issue.

It could be. Compare the lopper’s design and the cut you are attempting with the maker’s description of the tool’s intended use. Do not assume that an apparently sharp blade makes a lopper suitable for every branch or cut. The supplied guidance is general pruning-tool advice, not a specification for a particular lopper model. [S1]

For example, suppose the instructions for your loppers state a capacity, and you measure the branch at the place you plan to cut. If your measurement is greater than that stated capacity, the branch is outside the model’s listed limit. If it is not greater, continue checking whether the design and condition are appropriate; the comparison alone does not prove the tool is in good condition.

Look for visible damage and check the maker’s care instructions for your model. A blade may need sharpening or other attention, but do not assume that every problem can be corrected at home. RHS guidance says some damage may be too severe for home correction and may need assessment or sharpening by a tool workshop. [S1]

The guidance discusses pruning blades generally and specifically cautions readers to check the lopper maker’s instructions. Use those instructions to decide what inspection or care is appropriate for your tool. If the loppers appear damaged or continue to crush a branch that is within their stated capacity, seek the maker’s guidance or a workshop assessment.

Use this suitability check:

1. Identify the lopper model and find its stated capacity and care instructions.
2. Measure the branch where you intend to cut and compare it with that capacity.
3. Check the maker’s description of the tool’s intended use against the cut you are attempting.
4. Look for visible damage and consult the model’s care instructions.
5. If the cause remains unclear, or damage may need attention, ask the maker or a tool workshop for guidance. [S1]

Worked example: Your loppers’ instructions list a capacity, and you measure the branch at the intended cut. If the measurement is greater than the listed capacity, choose a tool whose instructions cover that branch. If it is within the listed capacity but the cut still crushes, check the intended use and condition of the loppers; do not treat the capacity comparison as a diagnosis. If you suspect damage, a workshop can assess whether sharpening or further attention is needed. [S1]