Both lengths use the same 87 x 38mm section. Choose 3.6m where the extra working length can reduce joints or produce several planned cuts, and 2.4m where a shorter repair or section would otherwise leave unnecessary waste.
Choose between the two lengths from the actual cut plan rather than treating the 3.6m rail as automatically better.
Both versions use the same 87 x 38mm rectangular timber section. The difference is the amount of continuous timber supplied: our 2.4m MOT Rail provides 2.4m, while the 3.6m MOT Rail provides another 1.2m of working length.
The 3.6m version is useful where one longer continuous piece avoids an inconvenient joint, or where several shorter pieces can be marked and cut efficiently from one rail. Planning those cuts before sawing can reduce the number of unusable short offcuts left at the end of a job.
For a smaller repair, the 2.4m length can be the more practical option if the additional 1.2m would simply become surplus material. It also retains exactly the same 87 x 38mm cross-section, so choosing the shorter stock length does not mean changing to a smaller rail profile.
Stock length should not be confused with unsupported span. The 3.6m measurement describes the timber supplied, not a claim that the rail should span 3.6m between supports. Measure the required pieces and support positions first, then choose the length that uses the material most efficiently from our square rails range.