PRECISION 123 BLOCKS

These 1-2-3 blocks are versatile setup tools for machining, fabrication, inspection, layout, and precision hobby work. Each block is hardened, heat treated, and precision ground on all six sides to provide the durability and accuracy needed for repeatable workshop setups.

With five 3/8″-16 tapped holes and eighteen untapped holes per block, they can be used in a wide range of clamping, fixturing, alignment, and positioning applications. Their cross-drilled design helps reduce weight while maintaining practical strength, and the precision-machined surfaces support accurate squaring and parallel setup work.

Features

• Hardened and precision ground on all 6 sides

• Heat treated and case hardened to HRC 58-62

• Designed for setup, inspection, layout, clamping, alignment, and fixture work

• Five 3/8″-16 tapped holes per block

• Eighteen untapped holes per block

• Cross-drilled construction helps reduce weight while maintaining strength

• Precision machined for accurate squareness and parallelism

• Supplied as a matched pair

Specifications

• Product Type: 1-2-3 blocks

• Quantity: 2 blocks

• Tapped Holes: 5 per block

• Thread Size: 3/8″-16

• Untapped Holes: 18 per block

• Hardness: HRC 58-62

• Surface Finish: Precision ground on all 6 sides

• Squareness Tolerance: Within 0.0001″

• Parallelism Tolerance: Within 0.0001″

• Height of Pair Tolerance: Within 0.0001″

Comes With

• One pair of 1-2-3 blocks

• 2 blocks total

FAQ

What are 1-2-3 blocks used for?
They can be used for machining setups, clamping, alignment, inspection, layout, fixture work, and other precision positioning applications.

Are all six sides precision ground?
Yes. Each block is precision ground on all six sides.

How hard are the blocks?
The blocks are heat treated and case hardened to HRC 58-62 for wear resistance.

Do the blocks have threaded holes?
Yes. Each block has five 3/8″-16 tapped holes.

How many untapped holes are in each block?
Each block has eighteen untapped holes.

How accurate are the blocks?
Squareness, parallelism, and the height of the pair are each specified to a tolerance within 0.0001″.

How many blocks are included?
The set includes one pair, for a total of two blocks.