[Updated 16 September 2022]
What is a Bore Gauge?
Bore gauges are essential tools used to measure the internal diameters of bores, which are simply holes. It is often used in the routine maintenance of equipment to check for the wear-out of parts for operators to know when they should change their equipment. When using a bore gauge, the base of the bore gauge will be inserted into the opening of the desired hole and adjusted to perfectly fit the diameter of the opening. Depending on the type of bore gauge, the setup and usage method may differ but nonetheless they all serve the same functions.
An example of a pistol grip bore gauge
You may have heard of a plug gauge before and might be wondering what the difference between a plug gauge and a bore gauge is. While a bore gauge measures the size of a bore, a plug gauge is used to inspect the accuracy of the bore. This means that the plug gauge checks to see if the internal diameter falls within the specified tolerance to ensure its accuracy. The plug gauge should be able to fit into the bore without using much pressure and stay standing in the bore without falling over. Most commonly, the plug gauge will have two ends, one fitted to the lower limit of the bore and the other to the higher limit.
Types of Bore Gauges
When it comes to bore gauges, there are many variations on the market. The main categories that bore gauges fall under are telescopic, small-hole, dial and digital.
1. Telescopic Bore Gauge
Telescopic bore gauges are one of the cheaper, albeit trickier options when it comes to bore gauges. Once the gauge has been inserted into the bore and locked in place, the handle is rocked in order to extract the exact bore diameter. This rocking movement compresses the two anvils that give the dimensions of the bore, which are fixed in place. The anvils are then measured using another tool such as a micrometer or caliper to read the measurement from the locked bore gauge. As the telescopic bore gauge relies heavily on the operator’s handling, human error may hinder the accuracy of the measurements collected.
The Moore & Wright Telescopic Gauge 315 Series comes as a 6 piece set to provide you with different sized gauges for your every need. The device features a spring loaded plunger that expands in the bore and locks directly. Additionally, the measuring faces undergo a process called micro-lapping which smooths the surface, ensuring that measurements can be taken with a higher degree of accuracy. The 6 pieces in the Moore & Wright Telescopic Gauge 315 set range from 8mm for the smallest size to 150 mm for the largest.
2. Small-Hole Gauge
A small-hole gauge works slightly differently from the telescopic bore gauge and its usage is favored when it comes to measuring small bores. It comes in two styles: the half-ball and the full ball. The small-hole gauge is inserted into the bore and slowly adjusted until a light pressure is felt. It is then removed and measured against a micrometer or caliper. The full-ball gauge is easier to set and maintain as compared to the half-ball gauge which tends to have more spring that may make the measurement wrong.
3. Dial Bore Gauge
Compared to telescopic bore gauges and small-hole gauges, the dial bore gauge can perform the same function of measuring bore sizes but with a more direct approach. The dial bore gauge works by rotating a knob to extend and retract three anvils that point out from the body of the gauge. When the anvils are extended to match the size of the bore, the measurement reading will be sent to the dial mechanism to be read. Do take note that dial bore gauges would have to be calibrated before each use.
The Moore & Wright Dial Bore Gauge 316 Series comes with a set of carbide tipped interchangeable contact points. These tips range from 6mm to 150 mm with a 0.01 mm resolution for dial readings and 0.001 mm resolution for the digital indicator for more accuracy. The Moore & Wright Dial Bore Gauge 316 Series also features unique self-centering capabilities for additional ease and accuracy when using it.
The Sylvac S_Dial Work CBG is a special version in their S_Dial Work series for use on cylindrical bore gauges. Once attached to the internal measuring instrument, the measurement readings will be displayed on the digital screen of the Sylvac S_Dial Work CBG which can be transferred easily through USB, RS232 and the built-in BluetoothⓇ wireless technology. Its wide range of functions include buttons such as a preset master button that can be programmed according to your needs.
4. Digital Bore Gauge
The most advanced type of bore gauge is a digital bore gauge that is either connected by cable to a readout or relies on wireless technology to read and transmit the data. These bore gauges are usually fitted with two to three anvils to measure with precision and some can even have extension attachments to measure wider and deeper bores. Variations in the design of digital bore gauges have allowed for some to be mounted with a handle to look like a caulking gun or pistol.
Examples of bore gauges that feature a pistol design would be the Sylvac Bore Gauge Pistol-grip X_Treme XTH and the Sylvac Bore Gauge Pistol-grip Xtreme 3 Holematic BT. With a measuring range of 2 mm to 300 mm, both models feature fixed anvils and a UKAS certificate for its rings. A difference between the two models is that the Sylvac Bore Gauge Pistol-grip X_Treme XTH uses s_connect proximity while the Sylvac Bore Gauge Pistol-grip Xtreme 3 Holematic BT has built-in integrated BluetoothⓇ technology on top of the s_connect proximity. Another difference lies in X_Treme XTH memorising 3 ring gauge values and the Xtreme 3 Holematic BT memorising 4 ring gauge values.
The Sylvac Digital Bore Gauge X_Treme XTD and the Sylvac Bore Gauge Xtreme 3 Digital BT are similar to the previously mentioned bore gauges except for the lack of the pistol design. The X_Treme XTD falls under the same series as the Pistol-grip X_Treme XTH while the Xtreme 3 Digital BT follows the Pistol-grip Xtreme 3 Holematic BT.
With a resolution of 0.01 mm and an accuracy of 0.004 mm, the Moore & Wright Digital Bore Gauge SCTHXY3M-MW Series can measure bores of up to 82 mm in depth precisely. The device boasts self-centering abilities of its anvils and a measuring range of 6 mm to 100 mm. The anvils on the Moore & Wright Digital Gauge SCTHXY3M-MW Series are coated in tungsten carbide for added durability and blind bore measurements can also be conducted on instruments 12.5 mm and above.
Bore Gauge Distributor in Singapore
LFC PTE LTD carries a wide range of bore gauge products in Singapore. We are the exclusive distributor for Sylvac bore gauges in Singapore. If you are looking for a bore gauge or wish to find out more, feel free to contact us for a consultation. We are able to do pre-consultation for your needs, bore gauge demonstrations and total after sales service of your bore gauges should you need any.
- Bore gauge. Retrieved 20 May 2021, from https://en.wikipedia.org/wiki/Bore_gauge
- Go/no go gauge. Retrieved 20 May 2021, from https://en.wikipedia.org/wiki/Go/no_go_gauge
- Lapping. Retrieved 21 May 2021, from https://en.wikipedia.org/wiki/Lapping
- Miller, L. (2021). What is a Bore Gauge?. Retrieved 24 May 2021, from https://www.wise-geek.com/what-is-a-bore-gauge.htm
- Henneberry, B. All About Bore Gauges - Definition, Sizes and Uses. Retrieved 24 May 2021, from https://www.thomasnet.com/articles/instruments-controls/all-about-bore-gauges-definition-sizes-and-uses/