Review on Precision Aluminum Setup Blocks Height Gauge Set with Laser Engraved Size Markings - Perfect Router and Table Saw Accessories for Woodworking Set Up (15pcs) by Chase Shetler

This set contains 15 gauges from 1/16" to 15/32" plus a 1"x2"x3" block. I used a Mitutoyo micrometer (accurate to + /- 0.0001") to check the parts and found that four parts did not meet specifications. The specification for this gauge set is +/-0.001 inch. Most parts are within specification, meaning they are between 1 and 1500 undersize. In other words, they are more or less within specification +/-0.001". within rounding error. The measured deviations on my sample are: thousand undersize 1/8" - 1.3 thousand undersize 5/32 - 1 Thousand undersizes 3/16" - 1.65 thousand undersizes <== = non-standard 7/32" - 0.9 thousand oversizes 1/4" - 1.25 thousand oversizes 5/16" - 0.65 Thousand oversize 3/8" - 2.7 thousand oversize <=== non standard 7/16" - 1.35 thousand oversize 15/32" - 1.9 thousand small <=== out of specification 1 /2" - 0.85 thousand small 23/32" - 0.35 thousand small 3/4" - 4.2 thousand small <=== inferior. /4" is particularly bad at 4.2k undersize. Since the set has a negative tolerance (meaning they are all slightly undersized, which is a good thing), you need to be careful when stacking to make sure there are no mistakes .In order not to add up to an unacceptable amount, always use a sheet or two of printer paper as a spacer to adjust the smaller size, but first you need to know the exact tolerance for each piece, as I did with a micrometer (or at least a good one caliper) have done A A sheet of 20 lb printer paper is about 0.004" thick. Although some sheets are slightly off spec, this is still a decent set. For woodworking, a few thousand off specs isn't critical.