The trimmer should be able to withstand a drop of 4' onto a concrete floor without parts misaligning, buckling, or fracturing. It should sustain only surface damage such as scratches and small dents.
The trimmer should be able to withstand impact by stones, dog bones and other garden debris without any detrimental effect on its performance.
The material should not be liable to attack by fungi, or it should be treated to prevent such an attack.
The materials used should be able to withstand:
- prolonged exposure to damp or wet conditions, without swelling, warping, or losing strength to an extent that results in either a loss of performance or a shortening of the productís life
- prolonged contact with soil, grass saps, weed-killers, moss-killers, fertilisers, fungicides and pesticides, without corrosion, loss of performance, or a shortening of the product's life
- attack by sea air, or the atmospheric pollution in industrial areas.
The materials used should not discolour or crack in reaction to sunlight.
The trimmer should be able to be hung vertically for months at a time in a temperature range of 20C to 50C without undergoing enough creep to affect performance or product life.
The trimmer's design and materials must be such that differential expansion is not a problem. Correct distances between parts must be maintained, with no fouling, in the temperature range encountered in use, ie 10C to 50C. The trimmer should also withstand dropping at this temperature.
Guide