What is Hammer?
{{About|the tool|the part of a [[piano]]|Hammer (piano)}} [[File:Hammer2.jpg|right|thumb|A claw hammer]] A '''hammer''' is a [[tool]] for putting [[nail]]s into objects such as [[wood]]. It has a long handle, and a tip with a flat end for hitting nails. The most common type of hammer (sometimes called a ''claw hammer'') has a curved end (on the other side of the hitting end) for pulling nails out. A '''sledgehammer''' is a hammer that has a longer shaft, and a more massive head. The user can swing it with two hands and apply more force. == History == Hammers were used around 3.3 million years ago.<ref>{{Cite web|last=Wong|first=Kate|title=Archaeologists Take Wrong Turn, Find World's Oldest Stone Tools [Update]|url=https://blogs.scientificamerican.com/observations/archaeologists-take-wrong-turn-find-world-s-oldest-stone-tools-update/|access-date=2020-10-21|website=Scientific American Blog Network|language=en}}</ref><ref>{{Cite journal|last=Hovers|first=Erella|date=2015|title=Tools go back in time|url=http://www.nature.com/articles/521294a|journal=Nature|language=en|volume=521|issue=7552|pages=294–295|doi=10.1038/521294a|pmid=25993954|s2cid=205085058|issn=0028-0836|via=}}</ref> The first hammers were made without handles. Stones attached to sticks with strips of leather or animal sinew were being used. Hammers with handles were made in 30,000 BCE during the middle of the [[Palaeolithic|Paleolithic]] [[Stone Age]]. The hammer was used for building, food and protection.<ref>{{Cite web|title=The history of the hammer from its prehistoric beginnings. {{!}} Tool Blogger UK|url=https://langs.co.uk/blog/2017/06/30/the-history-of-the-hammer-from-its-prehistoric-beginnings/|access-date=2020-10-21|website=langs.co.uk|archive-date=2020-10-26|archive-url=https://web.archive.org/web/20201026093058/https://langs.co.uk/blog/2017/06/30/the-history-of-the-hammer-from-its-prehistoric-beginnings/|url-status=dead}}</ref> == Classification of hammers == Hammers can be classified into two. They are: === Hand-powered hammers === [[Fi