I recently decided to upgrade from the crude key leveling blocks I had been using, and enjoyed making these blocks.
Working with small pieces like this can be a wood working challenge. Here’s the techniques I used:
I selected a a good long piece of stock (I used walnut) and milled it to 9mm X 25mm. I cut a 4mm X 10 mm slot in each end of the stock with a vertical cut on the tablesaw. With long stock and a tall fence this can be a comfortable, safe operation. This could also be done nicely on the bandsaw. While the stock was still long, I bored the countersinks for the nuts and the concentric through bores for the bolts at the drill press. I bored the countersink slightly smaller than the cross dimension of the hex bolt, so that it could be tapped in for a snug fit. I bored the through hole slightly smaller than the threads of the bolt, so that the wood block would act as a locking mechanism on the bolt. After boring, I cross cut the ends of the long stock to form the 25mm X 30mm blocks. Finally, I secured the nut in the block with a bit of super glue. The bolt I used was a #8 machine screw.