Skip to main content


Surface Gauges in machine tool

 Surface gauges are essential tools used in machine tools for measuring and inspecting the flatness, parallelism, and surface finish of workpieces. They are versatile instruments commonly employed in machining, metrology, and quality control processes. Surface gauges consist of a rigid base with an adjustable spindle or probe that allows precise measurement and comparison of surfaces.

The main components of a surface gauge include:

Base: The base is a flat, stable surface that provides a reference for measurements. It is usually made of hardened steel or cast iron to ensure stability and durability.

Spindle or Probe: The spindle or probe is an adjustable arm attached to the base. It consists of a round or cylindrical rod that can be moved vertically or horizontally to make contact with the workpiece surface.

Fine Adjustment Mechanism: A surface gauge often features a fine adjustment mechanism, such as a knurled knob or micrometer screw, which allows for precise positioning and control of the spindle movement. This mechanism enables the operator to make fine incremental adjustments for accurate measurements.

Dial Indicator Mounting: Some surface gauges come equipped with a mounting point or an attachment to accommodate a dial indicator. A dial indicator is commonly used in conjunction with a surface gauge to provide highly sensitive measurements of surface irregularities and deviations.

Surface gauges are employed in various applications within machine tools, including:

Surface Plate Work: Surface gauges are extensively used in conjunction with surface plates to measure the flatness and parallelism of workpieces. The gauge is set up on the surface plate, and the spindle is adjusted to contact the workpiece. By moving the gauge along the surface, the operator can identify any deviations or variations in the workpiece's flatness.

Inspection and Quality Control: Surface gauges are valuable tools for inspecting machined parts and ensuring they meet specified dimensional tolerances. They can be used to check the surface finish, straightness, and perpendicularity of features on a workpiece.

Setup and Alignment: Surface gauges aid in the setup and alignment of workpieces and fixtures on machine tools. They help position and level components accurately, ensuring proper alignment and minimizing errors in machining operations.

Surface Profiling: When used in conjunction with a dial indicator, surface gauges can measure the surface profile of a workpiece. By moving the gauge along the surface and recording the dial indicator readings, operators can obtain a profile of the surface irregularities.

In summary, surface gauges are indispensable tools in machine tools for measuring and inspecting surface characteristics of workpieces. They enable precise measurement of flatness, parallelism, and surface finish, aiding in quality control, setup, alignment, and surface profiling tasks.