Essential measuring tools for the home shop

[TomG]

By far, the tool I use most in my shop is a pair of 8" digital calipers. I keep them on a work shelf on my mill along with a calculator and a 12" rule. There is a caveat associated with calipers though. They are difficult to use for the inexperienced. Great care must be taken to be sure the calipers are held square to the work if you expect to get reliable readings. Don't fall into the trap of blindly believing the numbers on the screen, they may not reflect the actual size of what you are trying to measure. Also realize that calipers are not the tool to grab if you want to measure closer than a couple of thousandths. The way to learn how to use calipers effectively is practice. Sit down and take a bunch of measurements until you can reliably get the same measurement many times in a row.

The second most used measuring tools in my shop, when the calipers won't do are the 0-1" and 1-2" micrometers. They are capable of measuring with a precision ten times better than calipers, especially on round parts. With a little care and practice, you should be able to measure a part reliably within a couple of tenths with a micrometer.

Darren, I noticed that you mentioned getting a set of telescoping gauges. Those are definitely cheaper than a set of inside micrometers, until you add the set of outside micrometers required to use them. It's extremely difficult to measure a telescoping gauge with calipers and I wouldn't recommend it. A companion tool to go with the "T" gauges is a set of small hole gauges. I like the ones that have a flat end so you can measure shallow holes with them.

I would consider a depth mic an essential tool. My favorite has a thin, non-rotating rod that makes it a bit more versatile than the standard round rod type. You are correct, it is very difficult to measure depths with a pair of calipers.

Another measuring tool that I would add early to the mix is a cheap set of shop grade gauge blocks. They are extremely handy for measuring the width of slots, or doing comparison measurements with an indicator on a surface plate. The addition of a sine bar with enable you to accurately set up and measure angles as well. Enco has an 81 piece import set on sale for $139.99. Of course to use gauge blocks effectively, you would also need a surface plate, a dial test indicator and a base (your magnetic base will do in a pinch).

For squaring up stock in the mill, a good solid square is essential. I have them from 2" all the way up to 12", but the 4" is the one I use most. A good combination square is also quite handy.

Anything beyond these basic tools is based on need. If I come across a project that requires a special tool, that becomes the excuse to get it, although convincing the wife of it's necessity isn't necessarily that cut and dry.

Tom