Post hole diggers are simple in both design and construction. Their design consists of two long handles with blades attached to the ends. The two blades are fixed to each other by a bolt at the pivot point. The blades can be closed by moving the handles apart and opened by moving them back together, or vice versa, depending on the way the blades are joined.
Blades
The digger’s blades are rounded, in a similar way to the shape of roof guttering, which gives them a scoop-like appearance.
They are used to pierce the ground and lift up the earth. The ends of the blades are sharpened so that they easily pierce the ground and create a clean hole.
The blades are rounded in order to create a neat, circular hole when digging. Along with this, the rounded edges also minimise the chance of dirt falling out when removing soil from a hole.
Some models of post hole diggers have blades that are attached to the handles by bolts. This allows them to be removed and replaced by new ones when they are worn or damaged.
Pivot point
The position of the pivot point can either be between the blades or between the lower end of the handles, depending on the type of digger.
It consists of a bolt which holds the two sides of the digger together, and is the part which hinges the blades, allowing them to be opened and closed when hole digging.
Some diggers are designed with an additional pivot point, which is usually positioned half way down the handles. This extra pivot can alter the direction that the blades move when the handles are opened.
The digger’s handles are the part held by the user. There are two handles: one to be held in each hand.
The length of the handles determines how deep and narrow a hole can be dug. The longer the handles, the wider they must be pulled apart in order to fully close the blades and clamp the soil.
This is a disadvantage of some models, as the longer handles mean if a user wishes to dig a very deep hole, the top of the hole will have to be widened to accommodate the digger.
Other models avoid this problem by having offset handles, which allow the digger to go deeper down a hole before the handles start to cause an obstruction.
Not all models of post hole digger are equipped with hand grips. However, most modern versions have hand grips on the end of the handles for added protection and comfort when using the tool.
Hand grips ease the task of digging: they give the user a better grip on the handles and reduce the risk of slippage and hand blistering.