WEN 10423 3 x 2 x 1-Inch Steel-Hardened Precision 123 Blocks, Two Pack

Bought two sets, so four total.Cleaned them off with mineral spirits and some denaturated alcohol and measured all dimensions, and each end, with Mitutoyo calipers (precision to 0.0005"). They all landed on the 0 but depended on the pressure applied, meaning they are probably somewhere in their stated 0.0002" tolerance. The middles all dipped to X.9995" with the same pressure applied to the edges, but stayed at 0 with lighter pressure, so each of the blocks has a very mild dip in the middle, but that's ok.I also used a DIN 875/00 knife-edge reference square to check for square. They're good enough for wood working and some rough machining setups. Some corners were so good there was zero light leak. Others were off a bit. Definitely not ultra-precise blocks, but more than good enough for most needs, especially at this price point.Blocks like these make EXCELLENT clamping and square blocks for building boxes or other things where traditional full size woodworking clamping squares won't fit. They also won't flex or bend, so you can apply significant clamping pressure to use these to force tight joints into square.

These blocks are dead accurate and solid. Great for squaring up jigs, tool setup, or clamping small parts. Threaded holes are clean and consistent. Feels like a machinist tool at a woodworker's price.

I've found more uses for these blocks than I thought I would. Size is accurate, machining is high-quality. Quick set-ups for 1" / 2" / 3" increments, check square on both sides of a table saw blade at once, bolt them together to make a 90-degree corner block, hold-down for small light-weight glue-ups, etc.

I don't use these for high-precision machining; my work is primarily with scale models and model railroading. For that, they are perfect. They are solid, heavy, and perfectly square and when I checked them with a quality square, they were spot-on.These are incredibly affordable compared to buying similar tools from specialized hobby stores. I've seen some reviews that question the precision, but for my purpose of assembling model structures and ensuring everything is perfectly aligned, they work great. They are also perfect to use as weights for holding down glued parts. For any modeler, these are a fantastic value.

I saw complaints about thye sticky oil on these blocks. That didn't bother me, I like my tools to come in a protective coating. This stuff man not be MIL-SPEC Cosmoline, but it's darned close, and that's a GOOD thing. I wiped them down with solvent (naptha, I think?), which worked great. Then I ran a Q-tip through the holes to extract most of what was inside, leaving a slight coating, which I wanted. Any residual oil inside the holes is viscous enough that it hasn't oozed out. I don't know what steel this is, but I suspect it will rust pretty easily, so I run an oil-rag-in-a-can (a la Paul Sellers), over the blocks whenever I've used them. They haven't rusted at all, as of now.I saw reviews that talked about the inaccuracy of the hole-allignment. They are correct, the holes aren't aligned perfectly. That doesn't bother me, as I don't connect the blocks. For me, the holes only serve to make the blocks lighter, so that's OK for me.I also saw reviews that said the dimentions weren't correct - it was clear that they received METRIC blocks. Mine were spot-on in inches.For quick checks on 90° blade and fence set-up, these are just what I needed, For setting fence-to-blade distance at precisely 1, 2, 3, 4, 5, or 6 inches, they are quick and accurate. That's all I wanted.I suspect the steel is soft enough that dropping one on concrete will do major damage. So try not to drop them on concrete. Me? I'm clumsy, and will likely drop them, time to time. I put pieces of old carpet (free from the dumpster) under my bench and all my major power tools. God willin' an' if the creek don't rise, these will last me a lifetime.

A bit rough, but spot on size.

Surprisingly good quality, best bang for the buck, very usable.

Every machinist needs a 123 block. I bought these for a cheap set that will get abused on occasion , but im truly surprised at how accurate the size really is. Comparable to the better ones I've bought, but much cheaper.