Starrett 52081 Drop Indicator Spindle Square Steel

Product Description

The STARRETT 52081 is a drop indicator spindle square designed for use with vertical milling machines. It provides a rigid, repeatable reference point for mounting drop-style indicators during setup, tramming, and part inspection operations. Constructed from steel for durability in shop environments, the 52081 features a 0.38 inch shank diameter that fits standard spindle bores. Graduations resolve to 0.0005 decimal inch, making it suitable for precision alignment work where tight tolerances matter. Machinists and toolroom technicians rely on this type of accessory to hold dial or test indicators consistently in the spindle without runout-inducing slop.

The STARRETT 52081 is intended for vertical milling machine setups in toolroom, job shop, and production machining environments. It is most commonly used when tramming a milling head, locating a part datum, or checking squareness of a fixture. The 0.38 inch shank diameter seats directly into the spindle collet or chuck. This accessory suits machinists who require repeatable indicator positioning without a dedicated indicator holder mounted to the quill or knee.

Key Features

• Steel construction for rigidity and resistance to shop wear
• 0.38 inch shank diameter fits standard vertical milling machine spindles
• 0.0005 inch graduation resolution supports precision alignment and tramming
• Drop indicator style positions the indicator below the spindle centerline for direct surface contact
• Single-piece accessory with no adjustment hardware to lose or misplace

Compatibility

Designed as an OEM-style accessory for use with vertical milling machines requiring a drop indicator spindle square.

Installation Notes

Installation is performed by machinists or toolroom technicians. Power down and lock out the milling machine spindle before inserting or removing the shank from any collet or chuck. Seat the 0.38 inch shank fully in the collet and tighten to the collet manufacturer's standard procedure before taking any measurements. Do not exceed the indicator manufacturer's travel range when lowering the quill onto the workpiece surface.