The surface gauge is one of the most common marking tools used for scribing lines parallel to a datum surface.
Setting jobs on machines parallel to a datum surface.
Checking the height and parallelism of jobs, setting jobs concentric to the machine spindle.
Types of surface gauges
- Fixed Type Surface Gauge
- Universal Surface Gauge
1) Fixed Type Surface Gauge
The fixed type of surface gauge consists of a heavy flat base and a spindle fixed upright, to which a scriber is attached with a spug and a clamp nut.
2) Universal Surface Gauge
This has the following additional features when compared with Fixed type Surface Gauge.
The spindle can be set to any position.
Fine adjustments can be made quickly.
Can also be used on cylindrical surfaces.
Parallel lines can be scribed from any datum edge with the help of guide pins.
Parts and functions of a universal surface gauge
The base is made of steel or cast iron with a V groove at the bottom. The ‘V’ groove helps to seat on circular work. The guide-pins, fitted in the base are helpful for scribing lines from any datum edge.
The rocker arm is attached to the base along with a spring and a fine adjustment screw. This is used for fine adjustments.
The spindle is attached to the rocker arm.
The scriber can be clamped in any position on the spindle with the help of a snug and a clamping nut.