For starters, the question everyone keeps asking - it's not 1/8" (.125") or 1/16" (.0625"), it's .075", aka 14 gauge steel sheet. Reading an Amazon description that seems thin, but it's perfectly usable. I also have a PEC Tools P/N 5114 screw checker for metric, and that's the same thickness for $10 more. In shopping around I don't think anyone makes a plate-style screw checker thicker than this unless it's plastic.

The notation on the front is a little odd, but understandable if you follow the included guide. PEC has a slightly easier to read layout on their version, but it's fine once you get used to it.

For accuracy, the threaded holes seem fine, although the "drills" clearance hole column feels a little oversized - don't have anything to measure them with here in quarantine. The plating process did leave some rough edges, though nothing like the flashing visible in another reviewer's photos.

As another reviewer noted, the "Protective Plastic Carrying Case" is simply a heavy Ziploc bag. I guess it could be helpful to protect the painted markings if you're tossing it in a toolbox and carrying it around everywhere? It's not like it needs a carrying case if you just leave it by your hardware drawers in the workshop.

Overall, it does the job I need it to do - tells me the size of an SAE screw. Don't expect it to clean rusty or mashed threads, that's not its purpose. The PEC Tools 5112 is probably slightly higher quality, but quite a bit pricier on something that I'm already having trouble justifying not just making myself.

I have other tools for determining screw size, but they are slower, bulkier, and/or more error prone than this depending upon the tool. This is my first go to with a piece of hardware if I think it'll match since it's so fast. Once I've got a pretty good idea, I'll confirm with a larger female part since it only sports a few threads. I love how it fits inside my case of bulky male and female thread gauges.

Compact and effective for checking what screw you need.

Functions well for its intended purpose and could be worth $100 but for the following corner-cutting: (1) The listing claim that the tool is "1/8 Inch Heavy Gauge Steel" is incorrect, to be kind with the comment. The one that I received mic's out at 0.075 inches, which is closer to 1/16 inch than 1/8 inch (but still mostly enough threads to be useful if one is very careful); the "satin chromed steel" finish is nice, but stainless would have been timeless; printing rather than engraving of the lettering was not a high-quality idea; and the machining of the threads is not as perfect as required for a high-quality thread gauge.

To keep these critiques in perspective, this SAE thread gauge and it's two companion metric thread gauges from Ruelle are more useful and information-packed than any other thread gauges currently listed on Amazon. My rationale for that opinion is the rich set of thread pitches available with a set of all three gauges plus the inclusion of numbered tap drill bit diameter gauges. No other set comes close.

I believe that I perceive a certain proud but sad bit of American manufacturing history represented by these Ruelle thread gauges. According to my research, Ruelle Industries, Inc. was a tiny, family-owned manufacturer of these gauges located in a tiny township in Michigan, northwest of Detroit. I imagine that they "hung in there," slowly yielding ground quality-wise in a futile attempt to compete in a brave new market of $25 consumer-grade machine tools utilizing American-grade labor and materials. According to opencorporates.com, Ruelle Industries, Inc. became inactive and the corporation was dissolved in mid-2021, less than one year ago as of this writing. Thus I assume that the gauges currently for sale on Amazon are leftover stock. If so, it might be a good time to grab a piece of Americana. (The foregoing is nothing more than my experience with the product, ten cents of research and my personal conclusions. I have no other connection with or knowledge of Ruelle or the current sellers.)

I own multiple screw sizing tools of various types. Each has its strong and weak points.

I found myself reorganizing my bolts and screws, exchanging the plethora of bins, drawers, and boxes for a simpler system. I thought this would be easy until I realized what a mess the contents of all those bins and drawers were. Also, when I started adding a number of Metric screws my ability to immediately know which was what went bye-bye.

My new plan was to use 3x6 inch very tough, clear zip-closing plastic bags. I purchased 1000 of from Amazon. Each identical item would go into a single labeled bag. These bags would be collected by size and type into larger labeled bags and then into clear plastic boxes. I would never again spend hours looking through 40 thousand bins looking for what I want. The entire collection of all fasteners of every type fits into 6 boxes in 25% of the spaces. Boy was I surprised.

The problem was really how long it was taking me to sort using my existing sizing tools: thread gauges, diameter gauges, length gauges, micrometer, and taps and dies when I was really confused. So I purchased a full set of the three gauges Screw Check'r makes, one SAE and two Metric. This really sped the process up. And it also made some sense out of the nonsense of Metric Screwdome. SAE screws are a very orderly system. Metric is bizarre, especially the odd sizes that are supposed to come close to duplicating popular SAE sizes. 1/4-inch by 20 threads per inch is one of these SAE sizes that are poorly mimicked in metric.

Another area that confuses folks is the SAE #12-24, #12-28 and the 1/4"-28 size. It is hard to find the #12 sizes in home centers and hardware stores, but they have been very common in electronic equipment racks. Of course so are metric 6 mm by 1 mm pitch screws and cage nuts. They look similar, but never the twain shall meet.

The good news is that what looked like a project that was going to take several weeks of spare time was reduced to two days of spare time. I could not be happier with these Screw Check'r sizing tools. The new organization system has all sorts of surprising benefits. I find the exact screw in seconds. I usually use a number of similar screws in one project and they all usually come from one box--not multiple bins. The screws, nuts, washers, wood screws, sheet metal screws stay clean and orderly. They don't walk between bins. When I use a bag of screws up, it goes into my pocket for ordering replacements.

Are Screw Check'r perfect? Nope. They could be better. They could also cost a lot more. As with most quality tools, however, these should last my life time if I take care of them.

Positives: Clearly marked, the holes are organized. Study them for a minute before freaking out. Metric is screwy. Get over it. The machining is good. The plates are a heavy, which I like. Sizing a screw is fast. Stores easily in a plastic bag.

Negatives: The markings are silk-screened on, not laser etched. However they are coated with a very tough clear finish that seems to be hardened with a silica additive. The use I put them through did not impact the finish at all. It still looks new. A tiny bit of thread on a few of the holes split off, making slight burrs that I cleaned up with a needle file. The thickness of the plate does not provide many threads on some sizes, but there seems to be enough. I would not use one of these plates to clean damaged threads. Nor would I force a screw just because I was certain it had to be a specific size. I would rather throw a recalcitrant screw away, clean it with a file, or rethread it with a die.

Probably the biggest shortcoming of these is that they only work on screws, not nuts--and I would never try to size a tap with it.

The best part is that it is very fast and certain if you have both an SAE and Metric plate. And I love that.