View source for Engineering:Marking gauge

{{short description|Type of measuring tool for woodworking and metalworking}}
[[File:Marking gauges.jpg|right|thumb|300px|Stanley and Veritas marking gauges]]
[[File:Graminho Marking gauger.jpg|thumb]]
A '''marking gauge''', also known as a '''scratch gauge''',<ref>{{Citation | last = International Textbook Company | title = International library of technology | page = 11 | publisher = International Textbook Company | year = 1903 | volume = 31 | url = https://books.google.com/books?id=rU8JAAAAIAAJ&pg=PA11}}.</ref> is used in [[Engineering:Woodworking|woodworking]] and [[Chemistry:Metalworking|metalworking]] to [[Engineering:Marking out|mark out]] lines for cutting or other operations.<ref>{{Citation | last = Tolpin | first = Jim | title = Measure Twice, Cut Once | page = 64 | publisher = Popular Woodworking Books | year = 2007 | edition = 3rd | url = https://books.google.com/books?id=V8L8y1J8YcgC&lpg=PA64 | isbn = 978-1-55870-809-9}}.</ref> The purpose of the gauge is to scribe a line parallel to a reference edge or surface. It is used in [[Engineering:Joiner|joiner]]y and sheetmetal operations.

The gauge consists of a beam, a headstock, and a scribing or marking implement, typically a [[Engineering:Pin|pin]], [[Engineering:Knife|knife]], [[Engineering:Pen|pen]] or wheel. The headstock slides along the beam, and is locked in place by various means: a locking [[Engineering:Screw|screw]], [[Engineering:Cam (mechanism)|cam]] lever, or a wedge. The marking implement is fixed to one end of the beam.

==Types==
The marking implement is chosen depending upon the operation to be performed. Some marking gauges have the capability to allow a number of implements to be fitted, others do not; and a woodworker will often have a number of different types. A steel pin is used when scribing with the grain. A steel knife is used when scribing across the grain. The pen or pencil is used when the woodworker does not wish the surface to be marred. Generally speaking, the pin and knife yield more accurate marking than do the pen or pencil. It is also used to mark parallel lines to the face side and edge side.

===Variations===
The style of gauge which uses a knife instead of a pin is often described as a ''cutting gauge''. This tool is sometimes used to slightly "mark" the wood before a cut to prevent tearout later when doing the main cut with for example a circular saw.<ref>{{Citation|last=The Wood Whisperer|title=Avoid Tearout With This Simple Trick!|date=2015-10-30|url=https://www.youtube.com/watch?v=_gG9iCtNRjM |archive-url=https://ghostarchive.org/varchive/youtube/20211221/_gG9iCtNRjM |archive-date=2021-12-21 |url-status=live|access-date=2019-02-19}}{{cbignore}}</ref>
Other variations include a ''panel gauge'' which has a longer beam and larger headstock for scribing lines that are further from the reference edge. A [[Engineering:Mortise gauge|mortise gauge]] has two pins that can be adjusted relative to each other at the end of the beam. This gauge is used to scribe two lines simultaneously and is most commonly used to lay out [[Engineering:Mortise and tenon|mortise and tenon]] joinery.<gallery>
File:Setting up a marking gauge to 15mm.jpg|Setting a marking gauge to 15mm
File:Illustration showing how to use a marking gauge.png|Illustration showing a marking gauge in use
File:Gramil.jpg|A mortise gauge
File:Using a mortise gauge to strike a pair of lines (4).jpg|A mortise gauge being used
File:Illustration on using a marking gauge (side view).png|Illustration of a marking gauge in use
File:Panel gauge.jpg|A panel gauge, used for marking wide boards and sheet materials.
</gallery>

==References==
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{{Measuring and alignment tools}}

[[Category:Metalworking measuring instruments]]
[[Category:Woodworking measuring instruments]]

{{Sourceattribution|Marking gauge}}