AVB is correct that they are usually used as a tie down strap

However, Alroh cylinder mowers used to tension the engine to cylinder belt by tilting the engine by means of a lever on the handle bar, attached to a steel rod that bolted to the front left head bolt

This one is not a good example, but this gives you the general idea

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alroh1.JPG (36.66 KB, 23 downloads)
alroh 2.JPG (36.92 KB, 24 downloads)