A digging bar is a long, straight metal bar used as a post hole digger, to break up or loosen hard or compacted materials such as soil, rock, concrete and ice or as a lever to move objects. Known by other names depending on locale, structural features and intended purpose such as a hop bar or crowbar in Britain, Australia and New Zealand and slate bar, shale bar, spud bar, pinch point bar or San Angelo bar in North America, or just a bar. Not to be confused with a crowbar, which is short, curved and designed to provide leverage rather than to dig.
Common uses of digging bars include breaking up clay, concrete, frozen ground, and other hard materials, moving or breaking up tree roots and obstacles, and making holes in the ground for fence posts. They are often used where space would not allow the use of a pickaxe.
Materials and construction
The ends of a digging bar are shaped for various purposes. Typically, each end has a different shape so as to provide two different tool functions in one tool. Common end shapes include:
- Blunt — a broad, blunt surface for tamping.
- Point — for breaking hard materials and prying.
- Wedge — an unsharpened blade for digging, breaking and prying. A San Angelo bar has a wedge at one end.
- Chisel — a sharpened blade for cutting roots, digging and prying. A pinch point bar has a chisel at one end.
Bars are typically 5 to 6 ft (1.5 to 1.8 m) long and weigh 15 to 23 lb (6.8 to 10.4 kg). They are usually made entirely of cylindrical or hexagonal forged steel with a diameter of approximately 1 in (2.5 cm). Chisel and wedge ends typically have a blade width measuring 1 to 3 in (3 to 8 cm). Blunt ends typically have a diameter of 2 to 3 in (5 to 8 cm).
Log-peeling spuds are used to remove the bark from logs. These spuds typically have a wooden or steel handle of length 18 in (0.5 m) to over 6 ft (1.8 m). This tool is also called a Bark spud or a barking iron.
Fishing through holes in ice is common in many parts of the world. One of the earliest methods of cutting these holes was to use a device variously known as an ice spud or ice chisel. Many chisel variations exist, including jagged teeth, skewed edges, and different grind angles and chisel widths. Early ice spuds (before about 1925) often had wooden handles and a steel chisel fixed with a tang and collar or socket, similar to a carpenter's chisel. Ice spuds are still carried by many ice fishermen as a means to test ice thickness and safety; a single forceful thrust of the ice spud will often penetrate unsafe ice.
A spud bar has a chisel at one end that is intended for removing material through a chipping or shaving action. In the British Isles these typically have a narrow, unsharpened chisel point at one end and a point at the other end, with diameters up to about1.5 in (4 cm). Some have plastic grips on the shaft and some have wider chisel ends, or "rakes", for specific jobs such as removing old shingles and tar paper.
- DeLaRonde, Joe. Blacksmithing basics for the homestead. Layton, Utah: Gibbs Smith, Publisher, 2008. Print. 104.
- Griffith, Nathan. Husbandry: the surest, cheapest way to leisure, plenty prosperity, and contentment, plainly illustrated. Trout Valley, W. Va.: Cobblemead Publications, 1998. 30. Print.
- Dunster, Julian A., and Katherine Jane Dunster. Dictionary of natural resource management. Vancouver, BC: UBC Press, 1996. Print.
- Annual Report of the Commissioner of Patents, Part 2; Part 4. US Patent office. 1858. p. 291.