1×2×3 Setup Blocks Matched Pair 23 Holes .0001" Precision Steel | Ground hardened steel HRC 55-62, Ideal fixture blocks for CNC milling and workpiece layout

So good that this is me second pair. I found that I needed 2 pair for one of me setups.

The blocks worked great to keep my work square. They allowed me to shift my work around on my drill press with my work clamped.

Worked great.

Loved the 1-2-3 blocks

The dimensions are ok, or at least as good as my calipers can measure. Maybe a thou out here and there. Good enough for my woodworking, but not good enough for machining. They alone would knock them down to 4 or 3 stars. The critical flaw are the fixture holes. They're all drilled the same size, then half of them are tapped. That means you can't pass a bolt through one block into the other. What's worse, of they already to be tapped separately from each side, so the threads don't line up. Not the thread damage to the bottom left bolt in the image after I tried to thread it all the way through one of the holes. Avoid.

I needed a set of 1,2,3 blocks and came across this kit. When I got them - the kit was well oiled to prevent rusting which was good...after a lite cleaning, the blocks were good to go. The kit comes in a nice plastic box to keep everything together when not in use which is a nice extra. Will say, the only reason I didn't give the last star was that the screw threads were rough in the blocks...I had to run the screws through on each block screw hole to cut the threads. All in all , it's a good set for what comes with it.

Mine used up every bit of the .0003 tolerance based on my calibrated mic’s, thickness and parallel, but I don’t need anything better than that so they work for what I bought them for. I didn’t bother to run them through a full CMM inspection so can’t speak to the squareness and other features. Threads were clear and hardness seems acceptable. iMO these are a good buy and I would recommend them if the tolerance fits your needs.

Quite square with plenty of holes. Just the way Mom made ‘em as a kid.