Carmex SIR1250S27 Indexable Threading Toolholder

Product Description

The CARMEX SIR1250S27 is an indexable threading toolholder designed for internal threading operations on CNC lathes and turning centers. Built to SIR series standards, it features a 1.25 x 1.25 inch square shank and accepts 27IR inserts secured by a screw-clamp holding method. The toolholder is machined from steel and spans 10 inches in overall length, with a minimum bore diameter of 1.56 inches. It is intended for right-hand cutting and is configured without coolant-through capability. Machinists and toolroom technicians working in production or job-shop environments rely on this style of toolholder for consistent thread-form repeatability with indexable inserts.

This toolholder is suited for internal threading applications in ferrous and non-ferrous workpieces where bore access requires a rigid, close-tolerance bar. The SIR series toolholder style is commonly used on manual and CNC lathes in production threading operations. With a minimum bore diameter of 1.56 inches, it is appropriate for medium-to-large bore threading work. The back-of-bar to cutting edge dimension is 0.88 inches, and the center-to-cutting-edge dimension is also 0.88 inches, supporting accurate tool offset setup.

Key Features

• Internal, right-hand threading toolholder in the SIR series
• Accepts 27IR indexable inserts with screw-clamp holding method
• 1.25 x 1.25 inch square steel shank for rigid setup
• 10 inch overall length with 1.56 inch minimum bore diameter
• 5/8 inch insert inscribed circle for thread-form stability
• Configured without coolant-through for simplified setup

Compatibility

Designed for use with 27IR series indexable threading inserts. Verify insert geometry and thread standard against job requirements before installation.

Installation Notes

This toolholder should be installed by a qualified machinist familiar with lathe tooling setup and indexable insert systems. Power down and lock out the machine before changing inserts or adjusting the toolholder position. Ensure the shank is properly seated and clamped in the turret or tool block to the machine manufacturer's specified torque range. Handle indexable inserts with care - edges are sharp and brittle.