Hertel 1000189 Mtjn Turning Toolholder 3/4 Inch Shank

Product Description

The HERTEL 1000189 is a right-hand MTJN-style negative rake indexable turning toolholder designed for precision lathe work in metal cutting applications. It accepts TN..33. series inserts, secured by a clamp and screw holding method, delivering positive insert retention during interrupted and continuous cuts. The shank measures 0.75 inches wide by 0.75 inches tall, with an overall length of 4.5 inches and a head length of 1.12 inches. Steel construction provides rigidity and durability under standard turning loads. This toolholder is installed by machinists and toolroom technicians on manual and CNC lathes where negative rake insert geometry is specified.

This toolholder is suited for external turning operations on manual lathes and CNC turning centers in production and job-shop environments. The 3-degree lead angle geometry positions the insert for efficient chip formation during roughing and finishing passes. The back-of-bar to cutting edge measurement is 1 inch, providing predictable tool offset setup. No coolant-through capability is present, making it appropriate for dry or flood-coolant setups where through-tool delivery is not required.

Key Features

• MTJN toolholder style with negative rake geometry for stable cutting
• Right-hand orientation for standard OD turning setups
• Accepts TN..332 inserts with clamp and screw retention
• 0.75 x 0.75 inch steel shank for rigid machine tool mounting
• 4.5 inch overall length with 1.12 inch head length
• Back-of-bar to cutting edge: 1 inch for consistent tool offset

Compatibility

Designed to accept TN..332 (TN..33. series) indexable inserts with a 0.375 inch inscribed circle. Part of the Multi-Option series. Manufacturers catalog number references include MTJNR and LS123.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the spindle fully stopped and the machine in a locked-out, de-energized state per applicable lockout/tagout procedures. Use proper torque tools when securing the insert clamp screw to avoid overtightening or stripping. Verify tool offset and reach dimensions against your machine tool setup sheet before taking a first cut. Follow the machine tool manufacturer guidelines and applicable shop safety standards when setting tool height and confirming insert seating.