SMP Logga

Testing of protection against saw chain shot

We conduct testing according to ISO 11837 (Protection against saw chain shot) and ISO 21876 (Protective screens against saw chain shot) using a specially designed test rig at our testing laboratory in Umeå. These types of tests have been performed by us since 2002. We also offer customized testing services in the same field.


When a high-speed saw chain shot, such as one used in a harvesting unit, breaks, chain components can become detached and be propelled in what is known as a saw chain shot, reaching speeds of up to 500 m/s. These can pose a significant risk to safety if they penetrate protective screens or cabin walls.

As early as 2002, the test rig for saw chain shot was designed and manufactured to generate and study the occurrence of saw chain shot in a controlled manner. This test rig is internationally unique and served as the basis for the development of the ISO 11837 standard (Protection against saw chain shot). During the testing process, we have the capability to evaluate the protective capacity of protective screens against saw chain shot (ISO 21876) and assess the protective functions of the saw units.

Our testing is conducted impartially as we are not affiliated with any manufacturing interests.

The test reports can be effectively used as a basis for CE marking. They provide valuable information for the CE marking process, demonstrating that the product meets the safety requirements established by applicable standards and directives. The test reports offer insights into the protective capacity and can be highly beneficial for manufacturers during the CE marking of their products.

At SMP, we strive to conduct tests that promote safety and contribute to the overall improvement of chainsaw equipment.


The tests are conducted in the test rig according to ISO 11837. During the testing process, the recommended combinations of chainsaw chains and guide bars provided by the manufacturer are used. Chain speeds equivalent to normal operating conditions are generated. A chain break is initiated in the test rig to record the direction and speed of any potential saw chain shot. The results document whether the saw chain shot is prevented by the protective function of the saw unit (ISO 11837) or if penetration of the protective screen occurs (ISO 21876). In addition to the standard tests, customized testing beyond what is described in the standards can also be performed to meet specific customer requirements.


The report includes detailed information about each test, including comprehensive images, and provides an assessment of the results.

Stefan Frisk

Senior certifier

Anders Larsson

Certifier and testing engineer


Cannot find what you are looking for or are you curious about how we can help?


For more information or to place an order, please contact the person at the bottom of the page.



Testing of protective screens against chain shot and protection against chain ejection can be performed.


Testing, risk and safety

Delivery level



ISO 11837:2011, ISO 21876:2020


Price on tender

Delivery time

The delivery time depends on the scope of the test, but the test results can typically be reported within three weeks after the completion of the test.


Agreement on testing standards and testing procedures to be included is important. In the preparation process, the necessary documents and equipment should be available at least two weeks prior to the commencement of testing.