Somta Long Series Drill - HSS-E Parabolic Flute - 3.9mm

Somta Long Series Drill - HSS-E Parabolic Flute - 3.9mm is engineered for serious deep-hole work, delivering extended reach and precise results in thick metals. This 3.9 mm diameter drill bit is built to cut cleanly through multiple material layers without wandering, making it a dependable choice for demanding fabrication tasks.

The long length of this drill bit translates to genuine through-hole capabilities in challenging components where space is tight or access is limited. The HSS-E (high-speed steel enhanced) construction offers superior heat resistance and durability, enabling you to maintain steady performance at productive speeds even when drilling tough metals.

The standout feature is the parabolic flute design. It channels chips away from the cutting edge with remarkable efficiency, which lowers cutting forces and reduces friction and heat buildup. The result is smoother starts, faster material removal, and extended tool life—allowing you to drill deeper with confidence and less tool wear.

• Long-reach design for deep-hole drilling in thick workpieces
• Parabolic flute for efficient chip evacuation and reduced cutting forces
• HSS-E construction delivers superior durability and heat resistance
• Sharp cutting edges produce clean, accurate holes
• Flute geometry minimizes friction and heat buildup during prolonged drilling

Ideal for steel, stainless steel, cast iron, and other hard alloys, this drill excels in automotive fabrication, machinery housings, and any application requiring precise through-holes in thick sections. It offers a practical alternative to standard drills by combining extended reach with reliable performance under higher heat and tougher material conditions.

Operational tips for best results: choose appropriate spindle speed and feed rate for the material, use light cutting fluid to improve chip flow, and apply steady, even pressure to maintain alignment. If drilling through particularly thick or hard material, start with a shallow pilot depth to establish a true entry path, then gradually increase depth while continuing a steady cadence. After use, store in a dry environment to preserve the tool’s edge integrity.