Haimer 78.3/4Z0.3/8Z.1 Shrink-fit Extension 3/4 in Shank

Product Description

The HAIMER 78.3/4Z0.3/8Z.1 is a shrink-fit extension without a set screw, designed in a telescope-style configuration for use with shrink-fit toolholding systems in CNC machining environments. It accepts a 3/4 inch gage shank diameter and provides a 3/8 inch gage capacity, making it suitable for extending reach to deep-pocket or hard-to-access workpiece features. The gage head diameter measures 0.55 inches, and the overall length is 6.3 inches. The shrinking diameter range spans 0.55 to 3/4 inches. This extension is installed by tool and die technicians, CNC setup technicians, and precision machining professionals working with induction shrink-fit toolholding equipment.

This extension is intended for use in precision CNC machining applications where standard toolholder reach is insufficient. The telescope-style design allows the cutting tool to access deeper cavities or recessed features without compromising the rigidity advantages of shrink-fit clamping. It is appropriate for milling, drilling, and boring operations on vertical machining centers, horizontal machining centers, and similar spindle-driven equipment. The absence of a set screw eliminates interference with the shrink-fit clamping zone, preserving runout accuracy and clamping force throughout the extension assembly.

Key Features

• Telescope-style shrink-fit extension provides added reach without set screw interference
• 3/4 inch gage shank diameter for secure fit in compatible shrink-fit toolholders
• 3/8 inch gage capacity accommodates a range of cutting tool shank sizes
• Shrinking diameter range of 0.55 to 3/4 inches supports flexible tool selection
• 0.55 inch gage head diameter and 6.3 inch overall length suit deep-reach machining applications
• No set screw design maintains the runout accuracy characteristic of shrink-fit systems

Compatibility

Designed for use with shrink-fit toolholding systems that accept a 3/4 inch gage shank diameter. Compatible with induction-style shrink-fit machines capable of accommodating the 0.55 to 3/4 inch shrinking diameter range.

Installation Notes

Installation requires an induction shrink-fit heating unit rated for the shank and extension diameters involved. The toolholder and extension must be fully cooled to ambient temperature before measuring runout or proceeding with tool setup. Always follow the equipment manufacturer's heating time and temperature guidelines to avoid damage to the extension or toolholder bore. Handle heated components with appropriate thermal protection equipment.