Starrett Spindle Square Range Graduation Milling Machine Tramming Tool

The Starrett 649 Series Spindle Square is a precision tramming tool for setting the head of a vertical milling machine square to the table. Regular tramming keeps the spindle perpendicular to the work surface. This spindle square is a faster, more precise alternative to tramming with a single dial test indicator.

Key Features:

• Patented design made for head tramming on vertical milling machines
• Comes fully assembled with two AGD Group 2 dial indicators
• Solid steel body with a durable black finish
• Ground gaging surface for accurate, repeatable readings
• Includes a custom storage case

How It Works:

• Set both indicators to zero on a surface plate.
• Place the spindle square in the machine collet.
• Bring the head down to the table until both indicator needles have turned about one full rotation.
• The needles do not need to point in the same direction. Matching numerical readings, not needle position, show that the head is square.
• Adjust the machine with normal tramming procedures until both indicators read the same value. Set the X-axis first, then repeat for the Y-axis.

Starrett is a long-established American maker of precision measuring tools. The spindle square is available in inch and metric versions with different ranges and graduations. Choose the variant that matches your shop's measuring needs.