Carmex SIR0375H11 Internal Threading Toolholder 3/8 in

Product Description

The CARMEX SIR0375H11 is an indexable internal threading toolholder designed for right-hand cutting operations on CNC lathes and turning centers. Built to the SI toolholder style, it accepts 11IR indexable threading inserts secured by a screw-clamp holding method. The shank measures 3/8 x 3/8 inches with an overall length of 4 inches. The minimum bore diameter and maximum depth of cut are both 0.47 inches, making this holder suited to small-bore internal threading work. Machinists and CNC operators working in production threading applications will find this holder a direct-fit solution for precision thread forms in bored features.

This toolholder is intended for internal threading on metalworking lathes and turning centers where small-bore access is required. The 3/8-inch square shank fits standard tool blocks and quick-change toolpost systems sized for that shank. The back-of-bar to cutting edge dimension is 0.28 inches, and the center-to-cutting-edge offset is also 0.28 inches, allowing predictable tool positioning during setup. It is used in job shops, production turning operations, and maintenance machining environments where repeatable thread quality is required.

Key Features

• SI-style right-hand internal threading toolholder accepts 11IR indexable inserts
• Screw-clamp insert holding method for secure, repeatable insert indexing
• 3/8 x 3/8 inch square shank fits standard small-bore toolpost systems
• Minimum bore diameter of 0.47 inches suitable for small internal threading operations
• 4-inch overall length provides reach into standard workpiece bores
• No coolant-through design - external coolant application applies

Compatibility

Designed to accept 11IR series indexable threading inserts with a 1/4-inch inscribed circle. Compatible with tool blocks and quick-change systems sized for a 3/8-inch square shank.

Installation Notes

Installation is performed by qualified machinists or CNC setup technicians. Ensure the machine spindle is fully stopped and the machine is placed in an appropriate lockout state before changing or indexing inserts. Secure the toolholder in the tool block to the machine manufacturer's specified clamping torque using the correct wrench - do not over-torque the insert screw beyond the insert manufacturer's recommendation. Verify tool centerline height at setup to maintain thread form accuracy.