I learned a new term today and am super excited about it! It is called ‘Metrology’, which according to Wikipedia is “the science of measurement”. While DIY isn’t an exact science, I thought it would be useful time to review the basic measuring tools used in metal fabrication.
There are many different measuring tools used in metal fabrication some of which you may not have heard of before.
Here is the list I came up with roughly ordered from most used to least often used in my shop.
Eyeballing – Not kidding. The more projects you do, the more accurate you can ‘eyeball’ measurements. This all depends on the tolerance of your project though. If you are making a dish holder for your dog, I don’t think your dog will care if it is a 1/4″ off level. If you are making a part for an airplane, you better use more than just your eyeball. Which is why I came up with the list below.
Tape measure – buy lots of them so when you are deep in a project you won’t have to go searching for one. I prefer them with the fractional measurements printed on the tape (1/8, 1/4, etc.) because it takes less thought and reduces chances of error from math mistakes.
Ruler – The one I use in my shop is probably the same one I used in my high school classes. I do prefer one that is longer than 12″ because a lot of things commonly built in the shop are just over a foot. I believe the one in my garage is 15″. Also good for using as a straight edge for marking with SoapStone or Sharpie.
Combination Square – Good for marking cut lines. Put the slider part against a flat edge, then mark straight 45* or 90* lines. More accurate than a tape measure for making a mark or straight line extending in from the edge of a piece.
Quick or speed square – I shouldn’t admit this, but I will. I probably don’t use this for it’s original intention. I have no idea what most of the markings mean because I dislike wood and don’t build houses. I use this thing to make quick 45* and 90* cut marks on metal.
Magnetic Angle Finder – This one is a must have in my shop. I use it for my more accurate projects. Unlike the levels below, this one actually tells me degree of angle. That way if my garage floor is 2* out of level, then I can compensate for that angle when I am mocking up my project.
Sliding T Bevel – This one is used to replicate any angle from 0-360*. The wooden part sits on a flat side of your part, then you adjust the sliding steel part to either the angle you are looking for or to the angle of an existing part and lock it down with the knurled locking nut. You can then measure that angle with the above angle finder and replicate it.
Torpedo Level – Good for quick leveling on smaller projects. One side is magnetic so it will stick to your ferrous (steel) projects.
36″ level – Good for quick leveling on larger projects. I have one of these that is probably older than me and was given to me by my Dad (or maybe he wanted it back I just never gave it back to him?). Anyways, They are handy to have around the shop and can also be used on misc other house projects.
Digital Caliper – These things are very handy for measuring more precise projects, Bolt sizes, hole sizes, hole depth, etc. They used to be really expensive, back when I bought my digital caliper it was ~$45, now they are less than $20. They are a cheap yet very accurate multi-function measuring tool and are good to have around the shop. Do yourself a favor and get the digital readout kind.
Contour Gauge – These are good for replicating replacement or already built parts. You simply push this down on the part and the “fingers” match the contour of it so you can either trace or match it with the new part that you are making.
As a side note, I have found that it is much easier to find your tools when each is kept in a specific place. For example I have a drawer that has only tape measures, rulers, and small levels in it. When I need one of those tools, I know exactly where to look.
This is FAR from an all inclusive list of measuring tools, but it should be enough to get YOU started on YOUR projects. What are you waiting for? Get out there and make something!