A marking gauge, also known as a scratch gauge, is used in

woodworking Woodworking is the skill of making items from wood, and includes cabinetry, furniture making, wood carving, joinery, carpentry, and woodturning. History Along with stone, clay and animal parts, wood was one of the first materials worked b ...

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metalworking Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on e ...

to mark out lines for cutting or other operations. The purpose of the gauge is to scribe a line parallel to a reference edge or surface. It is used in

joiner Joinery is a part of woodworking that involves joining pieces of wood, engineered lumber, or synthetic substitutes (such as laminate), to produce more complex items. Some woodworking joints employ mechanical fasteners, bindings, or adhesives, ...

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sheetmetal Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate, ...

operations. The gauge consists of a beam, a headstock, and a scribing or marking implement, typically a

pin A pin is a device, typically pointed, used for fastening objects or fabrics together. Pins can have the following sorts of body: *a shaft of a rigid inflexible material meant to be inserted in a slot, groove, or hole (as with pivots, hinges, an ...

knife A knife (: knives; from Old Norse 'knife, dirk') is a tool or weapon with a cutting edge or blade, usually attached to a handle or hilt. One of the earliest tools used by humanity, knives appeared at least Stone Age, 2.5 million years ago, as e ...

pen PEN may refer to: * (National Ecological Party), former name of the Brazilian political party Patriota (PATRI) * PEN International, a worldwide association of writers ** English PEN, the founding centre of PEN International ** PEN America, located ...

wheel A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ...

. The headstock slides along the beam, and is locked in place by various means: a locking

screw A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the screw head, head. The most common uses of screws are to hold objects together and there are many forms for a variety ...

cam Cam or CAM may refer to: Science and technology * Cam (mechanism), a mechanical linkage which translates motion * Camshaft, a shaft with a cam * Camera or webcam, a device that records images or video In computing * Computer-aided manufacturin ...

lever, or a

wedge A wedge is a triangle, triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by conver ...

. 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 for a number of implements to be fitted, others do not; a woodworker will often have a number of different types. A steel pin is used when scribing with the grain, a steel knife when scribing across the grain. The pen or pencil is used when the woodworker does not wish the surface to be permanently marked. 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. 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 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

mortise and tenon A mortise and tenon (occasionally mortice and tenon) is a Woodworking joints, joint that connects two pieces of wood or other material. Woodworking, Woodworkers around the world have used it for thousands of years to join pieces of wood, mainly ...

joinery. 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.

References

{{Woodworking Metalworking measuring instruments Woodworking measuring instruments