Inside / Outside Micrometers & Bore Gauges

About Inside / Outside Micrometers & Bore Gauges

This category is brimming with over one hundred and fifty Mitutoyo precision products. Micrometers are instruments used by engineers and metrologists in almost all industries. They are available in digital, dial, and vernier styles allowing for a greater degree of measuring accuracy than alternative tools.

Also included in this category are Bore Gauges, which can measure the internal size of a hole. We also have a variety of accessories and tools to help optimise your micrometer. Please get in touch if you have any questions.

Popular Products

Mitutoyo Series 293 IP65 Digital Micrometer: These micrometers have two constant force mechanisms: Ratchet Stop and Ratchet Thimble. They also incorporate waterproof structural technology, providing IP65-rated protection against dust and water ingress. Features an easy-to-read large LCD, and models with measuring ranges of 75 mm (3 inches) or less offer an accuracy of ±1 µm.
Mitutoyo Series 103 Economy Outside Micrometer: Carbide measuring faces and a baked-enamel-finished frame offer durability, while the Ratchet Stop mechanism applies a constant measuring force.
Mitutoyo Series 139 Long Range Extension Tube Inside Micrometer: The 139 Series sleeve rotates to adjust the index line position when set to a length standard. Combining extension tubes with the micrometer head makes a wide range of inside measurements possible. They feature a graduation of 0.01 mm / .001" and a spindle feed error of 3 µm / 0.00015".
Mitutoyo Series 153 Non-Rotating Flat Carbide Tip Spindle Micrometer Head: Crafted for applications where standard spindles may introduce a twisting effect, the Mitutoyo Series 153 Micrometer Head features a non-rotating spindle that minimizes wear and protects workpieces from damage.
Mitutoyo Series 157 Optical Parallel: Use these optical parallels to evaluate the parallelism and flatness of micrometer-measuring faces. Each set includes four sizes, allowing for testing parallelism at quarter-turn positions of the micrometer spindle.
Mitutoyo Swivel Clamp Holding Bar: The Mitutoyo holding bars are specifically designed for use with Series 513 Swivel Clamps and come in five lengths: 50 mm, 100 mm, 115 mm, 2 inches, and 4 inches.
Mitutoyo Series 511 Bore Gauge: The 511 Bore Gauges have an increased grip size and hollow grip structure that reduces the influence of heat. They provide high-accuracy measurements while determining the diameter of holes.
Mitutoyo Series 177 Steel Setting Rings: Set dial bore gauges, Holtests, and the inside of micrometers accurately and quickly with the Mitutoyo's Series 177 Steel Setting Rings.

FAQs

What are the common types of micrometers and bore gauges?
Various types of micrometers exist in numerous forms, including outside, inside, depth, bore, digital, Vernier, and dial micrometers, each serving specific measurement needs. Bore gauges also vary, with rod-type, jaw-type, digital, and telescopic designs for measuring the inside diameter of bores.
What are the advantages of digital vs. analogue micrometers and bore gauges?
Digital micrometers and bore gauges offer clear, precise readings, higher accuracy, and features like data storage, inch/metric conversion, and automatic zeroing. Analogue models do not require batteries, are less susceptible to electronic malfunctions, are durable and reliable in harsh environments, and are often more affordable.
What is the difference between an inside and outside micrometer?
An outside micrometer measures external dimensions, such as the thickness or diameter. It has a spindle and anvil that close around the object being measured. An inside micrometer measures internal dimensions, such as the inside diameter of a hole or bore, using adjustable rods or jaws to span the internal width.
How do you read a micrometer accurately?
Align the thimble's zero mark with the sleeve. Read the sleeve scale for the whole millimetres or inches and any additional lines for tenths. Then, add the thimble reading (0.01 mm or 0.001 inches per graduation) to the sleeve reading. The combined result gives you the total measurement. Precision comes from careful alignment and reading of both scales.
How do you use a bore gauge to measure internal diameters?
Zero the gauge using a micrometer or ring gauge. Gently insert the gauge into the bore and expand the measuring head until it lightly contacts the internal surface. Read the measurement and note the position of the measuring head.
What is the typical accuracy of micrometers and bore gauges?
The typical accuracy of micrometers is around ±0.0001 inches (±0.00254 mm). Accuracy can vary for bore gauges unless a ring gauge is employed. An accuracy of ±0.0001 inches (±0.00254 mm) is possible with this.
What is the range of sizes that micrometers and bore gauges can measure?
Micrometers typically measure external dimensions, ranging from 0 to 25 mm (0 to 1 inch) for smaller models, larger versions can measure up to 100 mm (4 inches) or more, with specialised micrometers extending to 300 mm (12 inches) or even 1,000 mm (40 inches). Bore gauges generally measure internal diameters from about 3 mm (0.12 inches) to 600 mm (24 inches), with some high-precision models capable of measuring up to 450 mm. Always consult the manufacturer's specifications.
Can bore gauges measure deep bores accurately?
Bore gauges can accurately measure deep bores, especially when using models specifically designed for this purpose, which often feature longer measuring heads. Some gauges allow for extensions to reach greater depths while maintaining accuracy.
What materials are typically measured with micrometers and bore gauges?
Micrometers typically measure materials like metals, plastics, rubber, paper, and textiles. They measure thickness, diameter, and length. Bore gauges measure the internal dimensions of objects such as engine cylinders, pipes, bearings, and other machined components with cylindrical openings.