Inside Mike is the abbreviation of Inside micrometers. They are used for measuring inside dimensions such as cylinder bores or main bearing bores. But because there are easier ways of measuring inside dimensions with less expensive tools, I suggest you forgo the purchase of an inside micrometer. But because you should be familiar with this tool or you may want one of everything for your toolbox, let’s look at the inside mike.
Unlike outside micrometers , you need only one inside micrometer to get a range from one inch to six inches. This range is possible by interchanging various extensions. The problem with inside micrometers is they are extremely difficult to master. You must hold the mike square to the centerline of the bore and directly on center to get an accurate reading. This requires a lot of wiggling and adjusting one way and then another to get an accurate reading�?.then you’re not sure. What’s frustrating is it seems like every time you take a reading it’s different. Consequently, you’ll need a lot of practice before you can become proficient with using the inside micrometer.