A post hole clam-shell digger, also called post hole pincer or simply post hole digger, is a tool consisting of two articulated shovel-like blades, forming an incomplete hollow cylinder about a foot long and a few inches wide, with two long handles that can put the blades in an "open" (parallel) position or a "closed" (convergent) position.
The tool is used to dig holes in the ground, typically from a few inches to a about a foot in diameter, for general purposes such as setting fence and sign posts or planting saplings. In operation, the tool is jabbed into the ground with the blades in the open position. The handles are then operated to close the blades, thus grabbing the portion of soil between them. The tool is then pulled out and the soil is deposited by the side. The process is repeated until the hole is deep enough. Sometimes dry or sandier soils will not stay secured in the clams.