Carmex Extension With Internal Coolant Bore for Indexable Milling Holders (E25M12L100) is a precision threading extension that lets CNC mills cut external and internal threads in a single pass using helical interpolation. Designed for machinists and job shops, it delivers reliable, versatile threading with minimal setup and downtime.

• Internal coolant bore: Delivers coolant directly through the tool for cooler cutting and extended insert life.
• One-pass threading: Produce complete threads in a single tool pass, boosting throughput and reducing cycle time.
• Right- and left-hand threading with one holder: The same toolholder and insert can create both thread directions, simplifying setup.
• External and internal threading across multiple diameters: Versatile threading capability across a range of sizes using a single insert.
• Prismatic tail: Ensures exact, repeatable clamping in the toolholder for consistent performance.
• Double-sided inserts: Two cutting edges per insert extend useful life and reduce downtime for tool changes.
• Multilayer coating: Enhances wear resistance and allows higher cutting speeds for better productivity.
• Shoulder and blind-hole threading: Capable of threading to a shoulder pitch in blind holes with reliable results.
• Cost efficiency: Lower tooling costs compared with taps and dies, plus lower machine power requirements enable larger threads in fewer operations.
• Compatibility: Specifically engineered for use with E25M12L100 indexable milling holders to maximize performance.

This extension is ideal for high‑volume manufacturing, aerospace, automotive, and precision components where repeatable, high‑quality threads matter. It reduces tool changes, cuts cycle times, and delivers consistent thread geometry, even on challenging features such as blind holes or tapered thread forms. By combining reliable clamping, dual-edge inserts, and efficient coolant delivery, it helps shops boost productivity while managing tooling costs and maintenance.