Scriber
Encyclopedia
A scriber is a hand tool
used in metalworking
to mark lines on workpieces, prior to machining
. The process of using a scriber is called scribing and is just part of the process of marking out
. It is used instead of pencil
s or ink
lines, because the marks are hard to see, easily erased, and inaccurate due to their wide mark; scribe lines are thin and semi-permanent. On non-coated workpieces marking blue
is commonly used to increase the contrast of the mark lines.
They are a rod with a tip made of cast steel
that has been hardened
and tempered
. The point is sharpened to an angle of 30 or 40 degrees. Some scribers have a point at both ends. It is used by drawing the point over the surface of the workpiece to leave a shallow scratch on its surface.
A scriber block is used to layout lines at a set height from the base, thus its second name surface height gauge or just "surface gauge".
The work piece is held against an angle plate
so that it is perpendicular to the surface plate
, the scriber block is then adjusted to the required height and used to scribe a line parallel with the table, by sliding the block along the table's surface.
The scriber block has pins that can be pushed to protrude through the base, these can then be used as limit pins to allow the block to press against the edge of the table, controlling its movement in that plane. The upright post can be adjusted to tilt back or forward, effectively moving the scriber point up or down in a controlled fashion, coarse adjustments are made by sliding the scriber along its clamping block.
The scriber block may also be used in place of a dial indicator
to detect run out (a variation in concentric
ity) of a workpiece mounted in a four-jaw chuck. The scriber point acts as a visual reference against which any variation in the work piece can be judged.
Hand tool
A hand tool is a device for performing work on a material or a physical system using only hands. The hand tools can be manually used employing force, or electrically powered, using electrical current...
used in metalworking
Metalworking
Metalworking is the process of working with metals to create individual parts, assemblies, or large scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. It therefore includes a correspondingly wide range of skills,...
to mark lines on workpieces, prior to machining
Machining
Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...
. The process of using a scriber is called scribing and is just part of the process of marking out
Marking out
Marking out or layout is the process of transferring a design or pattern to a workpiece, as the first step in the manufacturing process...
. It is used instead of pencil
Pencil
A pencil is a writing implement or art medium usually constructed of a narrow, solid pigment core inside a protective casing. The case prevents the core from breaking, and also from marking the user’s hand during use....
s or ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...
lines, because the marks are hard to see, easily erased, and inaccurate due to their wide mark; scribe lines are thin and semi-permanent. On non-coated workpieces marking blue
Marking blue
Marking blue, layout stain or Prussian blue is a dye used in metalworking to aid in marking out rough parts for further machining. It is sometimes called Dykem...
is commonly used to increase the contrast of the mark lines.
They are a rod with a tip made of cast steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
that has been hardened
Hardening (metallurgy)
Hardening is a metallurgical and metalworking process used to increase the hardness of a metal. The hardness of a metal is directly proportional to the uniaxial yield stress at the location of the imposed strain...
and tempered
Tempering
Tempering is a heat treatment technique for metals, alloys and glass. In steels, tempering is done to "toughen" the metal by transforming brittle martensite or bainite into a combination of ferrite and cementite or sometimes Tempered martensite...
. The point is sharpened to an angle of 30 or 40 degrees. Some scribers have a point at both ends. It is used by drawing the point over the surface of the workpiece to leave a shallow scratch on its surface.
Scriber block
The work piece is held against an angle plate
Angle plate
An angle plate is a work holding device used as a fixture in metalworking.The angle plate is made from high quality material that has been stabilized to prevent further movement or distortion...
so that it is perpendicular to the surface plate
Surface plate
A surface plate is a solid, flat plate used as the main horizontal reference plane for precision inspection, marking out , and tooling setup. The surface plate is often used as the baseline for all measurements to the workpiece, therefore one primary surface is finished extremely flat with...
, the scriber block is then adjusted to the required height and used to scribe a line parallel with the table, by sliding the block along the table's surface.
The scriber block has pins that can be pushed to protrude through the base, these can then be used as limit pins to allow the block to press against the edge of the table, controlling its movement in that plane. The upright post can be adjusted to tilt back or forward, effectively moving the scriber point up or down in a controlled fashion, coarse adjustments are made by sliding the scriber along its clamping block.
The scriber block may also be used in place of a dial indicator
Dial indicator
Dial indicators, also known as dial gauges and probe indicators, are instruments used to accurately measure small linear distances, and are frequently used in industrial and mechanical processes...
to detect run out (a variation in concentric
Concentric
Concentric objects share the same center, axis or origin with one inside the other. Circles, tubes, cylindrical shafts, disks, and spheres may be concentric to one another...
ity) of a workpiece mounted in a four-jaw chuck. The scriber point acts as a visual reference against which any variation in the work piece can be judged.