Criterion S-1.5 1/2 ID Boring Head with 1 Shank and cutting bars

  

Criterion S-1.5 1/2" ID Boring Head w/ 1" Shank. Overall good working condition, no issues.

Some roughness shown in the last photo. You get what you see in the pictures.

The Criterion S-1.5 boring head is a compact, precision-engineered tool designed for milling machines and lathes, featuring a dovetail-style offset mechanism that allows for accurate enlargement of drilled holes with minimal runout-surprisingly rigid for its small size, making it a favorite upgrade over flimsier hobbyist alternatives like those from Sherline. It accepts boring bars up to 1/2 inch in diameter through its insert hole, enabling fine adjustments down to 0.001 inches per dial graduation for smooth, chatter-free finishes on holes as small as 0.05 inches. The model includes a straight shank with a 1-inch outer diameter for secure mounting in collets or spindles, often threaded at 7/8-20 on the back for shank interchangeability, and it's built to last with a wide bearing surface that enhances centering stability during high-production runs.