BS ISO 10726:2020 Portable chain-saws – Chain catcher- Dimensions and mechanical strength.
This document specifies the mechanical strength and dimension requirements, and the corresponding
test method for the chain catcher of chain-saws.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
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The chain catcher shall be positioned as far to the front of the saw body as practicable and shall extend at least 5 mm from the centre-plane of the guide bar. See Figure 1.
The chain catcher itself, its mounting and the saw body shall not have any tears or cracks when tested in accordance with Clause 6. The catcher shall also meet the dimensional requirement in Clause 4.
NOTE The catcher can bend during the test.
It is recognized that a chain catcher may seriously damage the saw chain upon contact. It is recommended
that the chain catcher should be made of a material that will not needlessly damage the chain.
6 Test procedure
The test temperature shall be —25 °C ± 3 °C, unless the chain catcher, its fastenings and the saw body are of metal, in which case the test may be conducted at room temperature.
The chain catcher shall be attached to the saw in a normal way. During the test, the chain-saw shall be fixed upside down (see Figure 2) by its handles.
The chain catcher shall be struck once with a pendulum hammer. This pendulum shall have a steel head with a flat strike face, with a width of 7 mm ± 0,2 mm, and an arm with a length giving 700 mm ± 5 mm distance between the swivel point and the centre of the head (see Figure 2). The arm shall be as light as possible. The pendulum system shall cause an impact force of 7,5 J ± 0,3 J from a drop height of 300 mm. The direction and the contact of the blow shall be along the guide bar centre-plane.BS ISO 10726 pdf download.