A crowbar, also called a wrecking bar, pry bar or prybar, pinch-bar, or occasionally a prise bar or prisebar, colloquially gooseneck, or pig bar, or in Australia a jemmy,[1] is a lever consisting of a metal bar with a single curved end and flattened points, used to force two objects apart or gain mechanical advantage in lifting; often the curved end has a notch for removing nails.

A crowbar with a curved chisel end to provide a fulcrum for leverage and a goose neck to pull nails

The design can be used as any of the three lever classes. The curved end is usually used as a first-class lever, and the flat end as a second-class lever.

Designs made from thick flat steel bar are often referred to as utility bars.

Materials and construction

edit

A common hand tool, the crow bar is typically made of medium-carbon steel, possibly hardened on its ends.

Commonly crowbars are forged from long steel stock, either hexagonal or sometimes cylindrical. Alternative designs may be forged with a rounded I-shaped cross-section shaft. Versions using relatively wide flat steel bar are often referred to as "utility" or "flat bars".

Etymology and usage

edit

The accepted etymology[2][3] identifies the first component of the word crowbar with the bird-name "crow", perhaps due to the crowbar's resemblance to the feet or beak of a crow. The first use of the term is dated back to c. 1400.[4] It was also called simply a crow, or iron crow; William Shakespeare used the latter,[5] as in Romeo and Juliet, Act 5, Scene 2: "Get me an iron crow and bring it straight unto my cell."

In Daniel Defoe's 1719 novel Robinson Crusoe, the protagonist lacks a pickaxe so uses a crowbar instead: "As for the pickaxe, I made use of the iron crows, which were proper enough, though heavy."

Types

edit

Types of crowbar include:[6]

  • Alignment pry bar, also referred to as Sleeve bar
  • Cat’s claw pry bar, more simply known as a cat's paw
  • Digging pry bar
  • Flat pry bar
  • Gooseneck pry bar
  • Heavy-duty pry bar
  • Molding pry bar
  • Rolling head pry bar

See also

edit

References

edit
  1. ^ Oxford English Dictionary. Oxford University Press. 1989. pp. jimmy 1, n. 6. ISBN 978-0-19-861186-8.
  2. ^ OED: crow-bar; crow, sense 5a
  3. ^ AHD: crow Archived 2008-03-12 at the Wayback Machine
  4. ^ Snopes: crowbar
  5. ^ "No Fear Shakespeare: Romeo and Juliet: Act 5 Scene 2". www.sparknotes.com.
  6. ^ "What is a Pry Bar and What Are They Used For?".