Transcript (en)

In Liaoning, China, these workers are splitting huge blocks of granite with little more than steel wedges and heavy hammers. They first make a row of holes along the planned fracture line. Steel wedges are placed inside, then struck one after another instead of hammering a single point. Each blow drives the wedges deeper and creates lateral pressure inside the stone. This produces tensile stress between the holes. Granite is strong under compression, but cracks can propagate when enough tensile stress builds along a controlled line. Eventually the small fractures connect and the entire block separates. The workers can then repeat the process, reducing the large slab into smaller rectangular pieces for further cutting or shaping. It looks simple, but spacing the holes and applying the force evenly matter. The hammer provides the energy, while the wedges determine where tons of stone finally give way. give way.