The Secret to Accurate Dial Indicator Readings

A dial test indicator is only as good as the part touching your workpiece. Machinists often overlook the contact point for a dial test indicator, yet this tiny component determines your final accuracy. Choosing the wrong tip leads to false readings and ruined parts.

Why the Contact Point Matters

The contact point transfers physical movement from the workpiece to the indicator gear train. Different inspection jobs require different shapes and materials.

If you use a worn or incorrect tip, you introduce cosine error. This mechanical error skews your measurements. Selecting the right contact point ensures perfect repeatability.

Common Types of Contact Points

Different shapes solve specific measurement challenges on the shop floor:

• Ball Points: The standard choice for flat surfaces. Ruby or carbide balls resist daily wear.

• Flat Points: Ideal for measuring convex surfaces or spheres.

• Pin/Needle Points: Perfect for reaching into narrow grooves, slots, or small holes.

Tips for Peak Precision

Maintenance Tip: Regularly check your contact points for flat spots. A worn ball point will distort your roundness measurements.

Always match the point length to your indicator's original specifications. Changing the length alters the leverage ratio of the internal pivot mechanism, which completely ruins the tool's calibration.

Additionally, ensure the thread size matches your indicator brand. Most manufacturers use either M1.6 or #4-48 threads.

Upgrade Your Setup Today

Do not let a worn tip compromise your machining quality. Inspect your contact point for a dial test indicator regularly. Swap out damaged tips today to keep your quality control flawlessly precise.

Selection of ball diameter : 0.5, 0.7, 1.0, 2.0 & 3.0mm

• Stylus length affects the scale factor of an indicato