Micro 100 ER16-312 ER16 Collet 5/16 Inch

Product Description

The MICRO 100 ER16-312 is an ER16-series spring collet designed to hold 5/16 inch (0.3125 inch) round shank tooling in ER16-compatible collet chucks. It delivers a total indicator runout (TIR) of 0.0004 inches, providing the concentricity control required for precision milling, drilling, and reaming operations. Weighing 0.1 pounds, the collet is compact and fits the standardized ER16 envelope. This collet is typically installed by machinists and CNC operators working with small-format spindles where toolholder accuracy directly affects surface finish and tool life.

The ER16-312 is suited for use in vertical machining centers, CNC routers, manual mills, and high-speed spindles that accept the ER16 collet standard. It is appropriate for light-duty to medium-duty cutting applications where a 5/16 inch tool shank is required. The collet does not support through-coolant delivery, making it best suited for air blast or flood coolant setups applied externally at the cutting zone.

Key Features

• ER16 series collet fits all standard ER16 collet chucks and toolholders
• 5/16 inch (0.3125 inch) bore accommodates common milling and drilling shank sizes
• TIR of 0.0004 inches supports precision concentricity requirements
• No through-coolant passage - compatible with external flood or air blast cooling
• Lightweight at 0.1 pounds for use in compact and high-speed spindle assemblies

Compatibility

Designed as an OEM-style replacement or standard collet for use in ER16-compatible collet chucks and toolholding systems accepting a 5/16 inch round shank tool.

Installation Notes

ER collets are installed by machinists using the appropriate ER16 collet nut and a calibrated torque wrench - consult the chuck manufacturer's torque specification before tightening. Always inspect the collet bore and chuck taper for chips, burrs, or surface damage before seating the collet. De-energize and lock out the spindle drive before performing any toolholder changes. Do not use damaged or out-of-round collets, as concentricity loss will affect machined part accuracy and accelerate tool wear.