Ever wish that you could have one of those nifty nut and bolt thread check/sizer gauges they have at Home Depot, Ace, etc? Well with a little time, you can have your very own in your home shop. There are commercial options available, but this one cost me a whole 15 bucks in materials. So follow along and I'll show you how to make your own. As usual, the second image was my inspiration for this project.

Materials Used:
1/4" Plexi Glass sheet (had on hand from another project)
Dymo Label Maker
Super Glue
Nuts and bolts in the following sizes (bolts as short as you can get for the size it comes in)
SAE:
#6
#8
#10
1/4"
5/16"
3/8"
7/16"
1/2"
5/8"
3/4"
Metric:
M4
M5
M6
M7
M8
M10
M12

Step 1: The Layout

The first thing I did was cut my plexi down to size. I've had mixed results doing this in the past but this time I managed to get a nice clean break. I could have used wood for the base or metal, but I had the plexi on hand so I used it.

Once I had it cut down to size my next issue was how to mark my layout without marking the plexi itself. The benefit of using the plexi came in nicely here. I just took a piece of paper and laid out a 1" x1" grid pattern on the paper and set it under the plexi on my workbench.

Step 2: Prepping the Hardware

The issue with glueing the bolts directly to the surface of the plexi is that most bolts are not flat on the heads. They come with grade or manufacturers marks cast into the heads. Obviously to ensure a secure bond, these needed to be eliminated. I just used a hand file and filed the heads down nice and flat. This has the added benefit of scuffing the surface to ensure a good strong bond, so I filed the nuts a little bit as well.

Step 3: Putting It Together

Next I laid the hardware out on my grid on the plexi. I had to make a few adjustments here for the larger nut and bolts. Luckily I did a dry lay out the first time before I glued them down to make sure I was going to be happy with the placement. Once I was, I picked each nut and bolt up and glued them in place one at a time.

For the smallest nuts, I found it worked well to use the bolt to help hold it in place as I was setting it. Just be careful not to glue the nut and bolt together by accident.

A Note here on the Super Glue, I choose to use it since I had some on hand. I did a strength test by gluing a half inch bolt to a scrap piece first. I was not able to easily break it off so I am fairly confident it will hold up just fine. Long term, well time will tell. If it ever does give I will re-set with a good 2 part epoxy.

Step 4: Labeling

Can I just say how much I love my Dymo Label maker?

Pretty simple at this point, I used white plastic coated labels in the machine. Made a label for each size as well as the labels showing SAE and Metric. Then just Peeled em and Stuck em. Simple, Clean and effective.