Starrett 12307 Dial Test Indicator 0.8mm Horizontal

Product Description

The STARRETT 12307 is a horizontal-style dial test indicator designed for precision measurement in machining, metrology, and quality-control applications. It features a jeweled bearing movement and a precision gear-driven design that delivers a maximum measurement range of 0.8 mm per revolution with a dial graduation of 0.01 mm. The 1.25-inch diameter yellow dial uses a 0-40-0 bidirectional readout for quick positive and negative deviation readings. The narrow-body housing carries a satin chrome finish and accepts a dovetail mount, making it compatible with standard indicator holders and surface-plate setups. Machinists, tool-and-die technicians, and QC inspectors are the primary users.

The 12307 is suited for horizontal indicator applications where the contact point must approach a workpiece from the side rather than from above. Typical uses include checking runout on lathe centers, verifying parallelism on milling fixtures, and inspecting surface flatness on a granite plate. The contact point reverses automatically, and a contact wrench is included for swapping to the second included contact point. The dovetail mount allows rapid attachment to a swivel post holder or tool post holder, both of which are included in the case. This indicator fits residential machine shops, industrial production floors, and calibration labs equally well.

Key Features

• Jeweled bearing movement for low friction and long service life
• Precision gear-driven design for repeatable, accurate readings
• 0.01 mm dial graduation with 0-40-0 bidirectional scale on a high-contrast yellow dial
• Contact point reverses automatically; replaceable contact points included
• Dovetail mount compatible with swivel post and tool post holders
• Narrow-body, satin chrome finish housing for access in tight setups

Compatibility

Designed as an OEM-style replacement and standard fitment for STARRETT Series 3909 horizontal dial test indicator applications using a dovetail-style mount.

Installation Notes

Installation is performed by machinists or metrology technicians using the included dovetail clamps and post holders. Secure the dovetail clamp snugly before zeroing the indicator to prevent drift during measurement. Always pre-load the contact point slightly against the workpiece to ensure the indicator operates within its calibrated range. Confirm the indicator stem is perpendicular to the measurement axis to avoid cosine error in readings.