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Leave a comment below! Or click on an individual tool to see more or leave a comment about that tool. |
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| Dial tread depth gauge |
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| Pen Depth Gauge |
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| This sales display is meant to illustrate the stages of tire wear, from no-problem to give-us-money-now-for-your-own-safety. The local Toyota dealership kindly let me have it when I explained that I needed it to take pictures of tire gauges for a book I was working on, thereby making it unnecessary for me to slip it in my pocket while they weren’t looking. |
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| Tread depth gauges don’t have to be accurate, and generally they aren’t. |
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| This tread depth gauge looks simple, but is actually readable to 0.1mm. |
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| This is sort of a hybrid between a depth gauge and a height gauge. A common use would be setting the height of a table saw blade above the table. |
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| Height gauges are basically a variation on calipers where the fixed jaw is replaced with a foot meant to stand on a flat surface, such as a milling machine table or precision granite flat (see next section). |
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| A fine old Mitutoyo Height Master gauge. Each of the blocks is a one-inch precision gauge block, and the stack as a whole deviates no more than 1/10,000” from exact one-inch spacing top-to-bottom. The blocks are staggered so you can take a measurement from either the top or bottom surface of any of the blocks. The dial is graduated in units of 1/10,000”, and is accurate to that level if properly calibrated. When you turn it, the whole stack of 12 blocks goes up and down together, with a total adjustment range of one inch. This range combined with the one-inch spacing of the blocks means you can get a top or bottom surface at any height from 0” to 12” with an accuracy of 1/10,000”. The mechanical digital display give you the height to the nearest 1/1000”, then you read the divisions on the dial to get the next digit. |
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| Tread depth gauge |
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| Cheap digital depth gauge, probably best used for tire tread measurements. |
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| A nicely-made Vernier-scale depth gauge, accurate to 0.02mm (1/1000 inch). |
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| There are cheap digital calipers, and therefore there are also cheap digital height gauges. This one is too cheap: the base is so badly made it could never give accurate results. |
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Do you have a better example of this kind of tool? Let me know by leaving a comment, and include a picture of it if you can so everyone can see!