findmall Silver Calibration Blocks 2.1 lbs sku-132354131

findmall Silver Calibration blocks are listed at 2.1 lbs each under sku-132354131. This matched pair of 1-2-3 machinist blocks has dimensions of 1" x 2" x 3" per block. Each block has 23 holes: 5 tapped 3/8-16 clamping holes and 18 untapped holes. All sides are square to within .0002" per inch, and each block is hardened and precision ground on all 6 sides.

The cross-drilled design is intended to reduce weight while maintaining strength. The listing also calls them 123 jig blocks.