Caliper Analog 3-Jaw INSIZE 3227-504, 20–50 mm measuring range, 0.005 mm resolution, set with rings

INSIZE 3227-504 analog 3-jaw caliper is a mechanical measuring tool designed for precise measurement of external and internal diameters within a 20–50 mm range. With a resolution of 0.005 mm, the instrument enables repeatable measurement of round parts, rings and bores. The three-jaw configuration ensures concentric contact with cylindrical workpieces, and the caliper is supplied as a set with calibration rings for workshop inspection, quality control and precision fitting operations.

Advantages

The three-jaw mechanical design offers consistent centring and stable contact on circular sections, reducing operator-induced variation. A fine graduated vernier with 0.005 mm resolution allows precise reading without electronics, making the tool robust for shop-floor environments. Supplied rings facilitate quick verification and simple setup for routine inspection tasks. The compact range of 20–50 mm targets small- to medium-diameter components commonly encountered in mechanical assemblies and precision parts production.

Suitable for

• Measuring external diameters of shafts and cylindrical parts
• Inspecting internal diameters of rings and bores within 20–50 mm
• Quality control and first-article inspection in workshops
• Precision fitting and assembly of bearings, collars and bushings

Key specifications

• Measuring range: 20–50 mm
• Resolution: 0.005 mm (vernier)
• Measuring type: analog 3-jaw caliper for diameters
• Included accessories: set with calibration rings for verification
• Contact style: three-jaw concentric contact for cylindrical workpieces

How to use

Position the caliper so the three jaws contact the cylindrical surface concentrically, then gently close the jaws until light contact is achieved. Read the main scale and the vernier to obtain the measurement with 0.005 mm resolution. For internal diameter checks, insert the jaws into the bore or ring and expand them until they make uniform contact; then read the scale. Use the supplied rings to verify accuracy before inspection and to familiarise operators with reading and handling procedures.

Usage recommendations

Before each measurement session, clean contact surfaces and verify the caliper against the supplied rings. Apply light, consistent pressure when closing jaws and avoid lateral forces. Store the instrument in a protective case to prevent damage and periodically check calibration if used in critical quality-control processes.