Engineering:Ball-peen hammer
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A ball-peen (also ball-pein) or machinist's hammer[1] is a type of peening hammer used in metalworking. It has two heads, one flat and the other, called the peen, rounded.
Etymology
In the word "ball-peen", peen,[2][3][4] probably comes from a North Germanic source; compare dialectal Norwegian penn ("peen"), Danish pind ("peg"), German Pinne ("the peen of a hammer"), Old Swedish pæna ("to pound iron with a hammer").[5]
Uses
Besides peening (surface-hardening by impact), the ball-peen hammer is useful for many tasks, such as striking punches and chisels (usually performed with the flat face of the hammer). The peening face or ball face is useful for rounding off edges of metal pins and fasteners, such as rivets. It can also be used to make gaskets for mating surfaces: a suitable gasket material is held over the surface that needs a gasket, and the operator lightly taps around the edges of the mating surface to perforate the gasket material.[6]
Crime
The ball peen hammer has been described as “the favourite weapon” of the Hells Angels.[7] It was also the weapon used by Peter Sutcliffe, dubbed the Yorkshire Ripper, an allusion to the Victorian serial killer Jack the Ripper, to murder at least 13 women and attack a further possible nine.
A ball peen hammer, along with a splitting maul, were the weapons used by 20-year old Richard Samuel McCroskey to murder 4 people in Farmville, Virginia.[8]
Variants
Variants include the straight-peen, diagonal-peen, and cross-peen hammer. Instead of a ball-shaped head, these hammers have a wedge-shaped head. The straight-peen hammer has a wedge oriented parallel to the hammer's handle. The cross-peen hammer's wedge is oriented perpendicular to the handle.[4] The head of a diagonal-peen hammer, as the name implies, has a wedge set at a 45° angle from the handle; it can be a left angle or a right angle, and some peen hammers have a double diagonal wedge[3] for ergonomic reasons.[9] They are commonly used by blacksmiths during the forging process to deliver blows for forging or to strike other forging tools.
Head materials
Ball-peen hammer heads are typically made of heat treated forged high-carbon steel[10] or alloy steel; it is harder than the face of a claw hammer.[11] Softer brass heads are sometimes used.
References
- ↑ Audel, Theodore (1962). Audel's new mechanical dictionary for technical trades. Theodore Audel. p. 54. https://books.google.com/books?id=L2LVAAAAMAAJ&pg=PA54.
- ↑ Don and Peg Doman (Jan 2021). "Ball Peen Hammers or Ball Pein Hammers All Look the Same to Me". https://thesubtimes.com/2021/01/14/ball-peen-hammers-or-ball-pein-hammers-all-look-the-same-to-me/..
- ↑ 3.0 3.1 "Double diagonal pein hammers". https://www.iforgeiron.com/topic/22642-double-diagonal-pein-hammers/.
- ↑ 4.0 4.1 Ryan, V. (2019). "Hammers - Ball pein, cross pein and straight pein". https://technologystudent.com/equip_flsh/hammers1.html..
- ↑ "Peen" in wikdictionary.
- ↑ Iniguez, Ramon C.. "Lesson Planner: How to make a gasket using a ball-peen hammer". CTE Online. California Department of Education. https://www.cteonline.org/curriculum/lessonplan/how-to-make-a-gasket-using-a-ball-peen-hammer-updated-by-ramon-c-iniguez/d2jo59..
- ↑ Sher & Marsden 2006, pp. 411–412.
- ↑ Williams, Reed (2009-11-03). "Richard McCroskey indicted in Farmville murders". WSLS News. Richmond Times-Dispatch. http://www2.wsls.com/news/2009/nov/03/richard_mccroskey_indicted_in_farmville_murders-ar-369714/.
- ↑ Black Bear Forge (2019). "Forging the double diagonal peen hammer part 1". https://www.youtube.com/watch?v=liuBBCn6-RE.. See also "Forging the double diagonal peen hammer part 2".
- ↑ Cavette, Chris, How a hammer is made, http://www.madehow.com/Volume-4/Hammer.html, retrieved Dec 19, 2024.
- ↑ Benford 2006, p. 36.
Bibliography
- Benford, Tom (2006). Garage and Workshop Gear Guide. MotorBooks/MBI. ISBN 0-7603-2312-7. https://archive.org/details/garageworkshopge0000benf.
- Sher, Julian; Marsden, William (2006). Angels of Death: Inside the Bikers' Empire of Crime. Toronto: Alfred Knopf Canada. ISBN 9780307370327.
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