Carmex SR0390H12 Indexable Thread Mill 0.39 in Cut Dia

Product Description

The CARMEX SR0390H12 is an indexable thread mill designed for precision internal thread milling operations in machining and metalworking applications. Built from alloy steel, this toolholder accepts one I/E style insert secured by a screw-clamp holding method, allowing for quick insert changes without removing the holder from the spindle. The cutting diameter measures 0.39 inches with a neck diameter of 0.30 inches, a 0.75 inch shank diameter, and an overall length of 3.35 inches. Through-coolant capability directs fluid directly to the cutting zone, helping to manage chip evacuation and extend insert life during thread milling cycles.

This thread mill is suited for CNC machining centers performing internal thread milling in alloy steel and similar ferrous materials. The SR toolholder style with a 0.75 inch straight shank fits standard ER or milling collet chucks. Maximum hole depth reaches 0.51 inches, making this tool appropriate for shallow-to-medium depth threaded holes in production and job-shop environments. Machinists and CNC programmers in manufacturing, toolroom, and production machining settings are the primary users of this tool.

Key Features

• 0.39 inch cutting diameter for precise thread milling in small-to-mid bore applications
• Through-coolant design directs fluid to the cutting edge for improved chip evacuation and tool life
• Accepts one I/E style insert (size 12 mm) secured by screw-clamp method for repeatable insert indexing
• Alloy steel toolholder construction provides rigidity and resistance to deflection under milling loads
• 0.30 inch neck diameter allows reach into bore without holder-to-wall interference
• Compatible insert screw S12 and key K12 for straightforward insert maintenance

Compatibility

Designed for use with I/E style threading inserts in size 12 mm. Compatible insert screw is S12 and the required key is K12. Fits CNC machining centers with standard collet or milling chuck systems accommodating a 0.75 inch shank diameter.

Installation Notes

Installation and tool changes should be performed by a qualified machinist or CNC toolroom technician with the spindle fully stopped and the machine in an e-stop or lockout/tagout condition per shop safety procedures. Verify collet or chuck bore size matches the 0.75 inch shank before clamping. Confirm through-coolant passages are clear and that the machine coolant-through feature is enabled at the spindle before running the program. Follow insert manufacturer torque guidance when seating the I/E insert with the S12 screw to avoid over-torque and insert fracture.