Inside Micrometer, 3 Point, 6~8 mm Range

Q1: What is an inside micrometer?
A1: An inside micrometer is a device designed to precisely measure things such as the inner diameter of holes. They look like fountain pens with a rotating thimble in the middle. Every time the thimble is turned, the micrometer expands. The thimble expands until the end of each tool touches the inside of the pipe, then a numbering system is used to find the measurement on the thimble.

Q2: How does an inside micrometer work?
A2: The picture below shows a 3-point inside micrometer with a measuring range of 11~14mm. When the force measuring device 6 is rotated clockwise, it will drive the micrometer screw 3 to rotate and make it move along the helical direction of the threaded sleeve 4, so the square conical thread at the end of the micrometer screw will push the three measuring jaws 1 For radial movement. The elastic force of the torsion spring 2 makes the measuring claw fit tightly on the square conical thread, and expands and contracts with the advance and retreat of the micrometer screw. The radial pitch of the square conical thread of the 3-point internal diameter micrometer is 0.25mm. When the force-measuring device rotates clockwise for one revolution, the measuring jaw 1 will move outward (radially) by 0.25 mm, and the diameter of the circle formed by the three measuring jaws will increase by 0.5 mm. When the microtube rotates once, the measurement diameter increases by 0.5mm and 100 equal divisions are engraved on the circumference of the microtube, so its reading value is 0.5mm÷100=0.005mm. This is how an inside micrometer works.

Tips: 4 Types of Micrometers

• Thread micrometer: Thread micrometer is also called outer diameter micrometer and screw micrometer. It is a length measurement tool with higher precision than the vernier caliper and can measure thousandths.
• Digital micrometer: The digital micrometer is also a kind of outer diameter micrometer. It is different from the conventional outer diameter micrometer. It has the addition of intelligent digital measuring components, automatic reading, and saving reading time.
• Inside micrometer: The inside micrometer is mainly used to distinguish the outer diameter micrometer, which is a precision instrument for measuring the internal size of objects and is suitable for small and medium-sized direct inner wall measurement. SISCO provides internal micrometers with a measuring range from 6mm to 100mm.
• Lever micrometer: The lever micrometer is also called the indicator micrometer, which is a precision measuring tool composed of a micrometer cylinder part of an outer diameter micrometer and an indicator table.

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