Fowler Ultra-Precision 1-2-3 Block Set – 52-439-032-0

• Ideal for precision layout and set-up.
• Each block precision ground on all 6 surfaces.
• Case hardened to HRc 50 – 60.
• Surface finish from 6 to 16 micro inches.
• Squareness on all sides to within .0001″.
• (23) Holes: (5) 3/8″-16 tapped; (18) untapped thru holes
• Oversized to allow for nominal lapping .0001″~.0003″.

Includes:

• A matched pair of 1″ x 2″ x 3″ blocks.
• (5) 3/8-16 stainless steel socket head cap screws, hex key.
• Molded case