Inside Micrometer, 3 Point, 10~12 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: How to maintain the inside micrometer?

1. Check whether the zero line of the inside micrometer is accurate.
2. When measuring, the measured surface of the workpiece should be wiped clean.
3. When the workpiece is large, it should be measured on a V-shaped iron or a flat plate.
4. Before using the internal micrometer to measure, the measuring rod and anvil need to be wiped clean.
5. A ratchet device is required when screwing the movable sleeve.
6. Do not loosen the back cover to avoid changing the zero line.
7. Do not add ordinary engine oil between the fixed sleeve and the movable sleeve.
8. After using the inside micrometer, wipe it clean and oil it, put it in a special box and put it in a dry place.

Thank you for buying industrial test and measurement equipment on SISCO.com, all products sold by SISCO and the partner cover a 12 months warranty, effective from the date of receiving the products.

What is covered?

SISCO is responsible for providing free spare parts, and free technical support to assist the customer to repair the defective products until the problem is solved.

What is not covered?

• Product purchased from anyone other than a SISCO store or a SISCO authorized reseller.
• Expendable parts.
• Routine cleaning or normal cosmetic and mechanical wear.
• Damage from misuse, abuse or neglect.
• Damage from use of parts other than SISCO approved.
• Damage from use outside the product’s usage or storage parameters.
• Damage from use of parts not sold by SISCO.
• Damage from modification or incorporation into other products.
• Damage from repair or replacement of warranted parts by a service provider other than a SISCO authorized service provider.
• Damage caused by the application environment not meeting the product usage requirements and the failure to perform preventive maintenance.