The 3 imperial sets contain a 1″ x 2″ x 4″ (1-2-4) machined block and a set of narrower blocks that are all 1/2″ wide and 4″ long and of varying thicknesses that range from 1/32″ to 31/32″. The 13-piece set has all the standard thicknesses that I most commonly use (from 1/32″ to 3/4″). By stacking these block together I can obtain most other dimensions I need. For example, stacking the 3/4″ block with the 1/8″ block gives me a 7/8″ thickness. If I need to set a dado blade to cut a groove for 3/4″ (which is really 21/32″ thick) I stack a 15/32″ block with a 3/16″ block. If you’re math challenged there is always the 42-piece set that has everything (and is also available in an optional Systainer). The metric set includes a 25mm x 50mm x 100mm block and nine bars from 0.5mm to 32mm.

You can use setup blocks for a myriad of tasks in the shop on most machines, including the table saw, jointer, bandsaw, shaper, drill press, router table and mortiser. They’re also ideal for use with handheld routers.

I use setup blocks to square the fence on most of my shop machines; to set the exact depth of cut on the router table, table saw and drill press; to set the fence for resawing; and to check that the outfeed table on my jointer is set flush with the cutterhead.

I do a lot of work with the router and find that setting bit depth goes much quicker when using the setup blocks. They’re particularly useful on the router table for setting the distance from the fence to the inside or outside of the router bit. They also make quick work of squaring the chisel and setting the distance from the fence on the hollow chisel mortiser.

And they can also be used with hand tools. You can set exact measurements on marking or depth gauges more quickly than with a ruler or tape measure.

I use the 1-2-4 block most frequently (for fence alignment). It has a larger contact surface than my small engineers square and is heavy enough to stay where it’s placed. When ripping narrow stock I set the fence distance with the large block and stack one or more of the narrow blocks to get the exact dimension I need. For example to rip drawer runners at 1-3/16″ I simply butt up the 3/16″ block against the narrow side of the 1-2-4 block.

I checked all the blocks in the 13-piece set and they were dead accurate. The anodized aluminum surface is extremely hard so the blocks should do a good job of resisting scratches. The thickness of each of the blocks is laser etched on one surface. I also find that the red surface makes a good contrast when placed against tool edges. Treat them with respect and these blocks will maintain accuracy for decades to come.

Once you start using these blocks I think you’ll find them indispensable for making accurate measurements in the shop on a wide range of shop machinery.