Bore Measuring Device

The Normaco Bore Measuring Device is a snap gauge for measuring bore diameters during line boring—without removing the boring bar. Designed for accuracy and efficiency, it allows machinists and field operators to take quick, repeatable measurements during on-site machining or workshop operations. It is designed to have minimum amount of assembly required before use. This device has a measuring range of 45mm to 300mm and a compact round or square  body, making it compatible with various boring setups. We offer three sizes, round 12 and 10mm, and square 12mm.  Additionally with an adaptor sleeve snug fit to larger tool ports (eg. 14mm) can be achieved. The smallest bore that can be measured depends on the boring bar.

How It Works

1. Assemble the Device – Determine the approximate bore diameter and check the reference table to select the correct device body and extension rod. Assemble the parts accordingly.

2. Prepare the Device – Press in the spring-loaded plunger and secure it with the locking screw.

3. Position in the Bore – Insert the device through the boring bar of the line boring machine and feed it into the bore.

4. Take the Measurement – Release the screw to allow the spring-loaded measuring rod to extend and make contact with the bore surface.

5. Retrieve & Read – Tighten the screw to lock the reading, remove the device, and use a caliper to determine the bore diameter.

Key Features & Benefits

• Measures through the boring bar — take bore diameter measurements without removing the bar from the bore, saving time during line boring operations
• Modular design — select the correct body and extension rod to cover bore diameters from 45 mm to 304 mm; extendable to 493 mm with the BMT Add-On Set
• Minimal assembly — ready to use quickly on site, with no loose springs to manage
• Multiple tool port sizes — round 12 mm, round 10 mm, and square 12 mm bodies cover most boring bar tool port sizes; adapter sleeves extend compatibility to 14 mm and 16 mm ports
• Spare parts included — kit contains spare springs and screws for when a small part goes missing during field work
• No batteries or electronics — purely mechanical design, reliable in demanding on-site machining conditions

Perfect for machinists, on-site technicians, and metalworking professionals, this snap gauge is a must-have for ensuring precise bore diameters during line boring operations.

Custom Solutions

If you require a different measuring range, body shape, or special modifications, we can provide customized solutions to meet specific project requirements. Contact us to discuss your needs.