Carmex Internal UN Threadmill Insert 21mm / 24 TPI / 21 I 24 UN MT7

Mill-Thread Insert – UN 24 TPI, Internal

The Carmex 21 I 24 UN MT7 is a high-precision internal thread milling insert engineered for cutting Unified (UN) 60° thread profiles with a 24 TPI pitch. Designed for CNC milling machines with helical interpolation, this insert delivers smooth, accurate, and repeatable threading performance for fine-pitch applications where precision and surface quality are critical.

Crafted from MT7 ultra-fine carbide, the insert offers exceptional hardness, wear resistance, and heat stability for extended tool life. Its 21 mm size, 12 mm height, and 4.7 mm thickness provide excellent rigidity and accuracy during cutting. Optimized for fine-pitch internal threads, it ensures tight tolerances and superior surface finishes across a wide range of materials.

Key Features & Benefits

• Ordering Code: 21 I 24 UN MT7
• Thread Type: Unified (UN) – 60°
• Threading: Internal
• Insert Size: 21 mm
• Pitch: 24 TPI
• H (Height): 12 mm
• T (Thickness): 4.7 mm
• Carbide Grade: MT7
• Applications: Fine-pitch internal UN threading for aerospace, precision engineering, and automotive components
• Advantages: High accuracy | Wear-resistant carbide | Consistent thread form | Superior surface finish

Carmex Precision Tools Ltd. is a world-leading manufacturer of cutting tools for threading and milling. Their extensive product range includes Thread Turning Inserts and Toolholders, Mill-Thread Inserts and Tool Holders, Solid Carbide Threadmills, and Spiral Mill-Thread Systems — all designed to deliver outstanding accuracy, durability, and performance in modern machining applications.