A German carpenter (Zimmerer) hewing a log into a beam. Note the blue ch: lk line snapped on the log to which the hewer works. Image © Patrick-Emil Zörner via Wikimedia Commons

In woodworking, hewing is the process of converting a log from its rounded natural form into lumber (timber) with more or less flat surfaces using primarily an axe. It is an ancient method, and before the advent of the industrial-era type of sawmills, it was a standard way of squaring up wooden beams for timber framing. Today it is still used occasionally for that purpose by anyone who has logs, needs beams, and cannot or would prefer not to pay for finished lumber.

Hewing is the last step in the process and occurs after log selection and felling, scoring and joggling. Hewing is done on the logs sides with a broadaxe. Hewing occurs from the bottom of the stem upwards towards what was the top of the standing tree, reducing the tendency of the broken fibers to migrate inwards towards the eventual beam.

Some 19th-century timber buildings in the U.S. have hewn long timbers in the same framing with vertically sawn and the later technology of circular sawn timbers. The reason for this is the long timbers were easier to hew with an axe than to take to a sawmill due to poor transportation routes.

Source: https://en.m.wikipedia.org/wiki/Hewing