304 316L Stainless Steel Hard CNC Milling Fine Micro Drill Bit

Product Description

Hard 304 / 316L Stainless Steel CNC Milled Micro Drill Bits are high-precision, solid carbide cutting tools engineered for drilling exceptionally small and accurate holes in tough stainless steels. Unlike standard twist drills, these are manufactured from a solid rod of ultra-fine grain carbide, then precision-ground into their final form using advanced 5-axis CNC grinding technology. They are specifically designed to withstand the high cutting forces and heat generated when machining work-hardening materials like 304 and 316L stainless steel. Featuring optimized flute geometries, point angles, and specialized coatings, these micro drills deliver superior hole quality, positional accuracy, and extended tool life in demanding micro-machining applications.

Product Processing

1. Material Selection & Blank Preparation: Solid rods of micro-grain tungsten carbide (WC-Co), often with a high cobalt content for toughness, are selected. The rods are precision centerless ground to a consistent diameter.

2. CNC Precision Grinding (Core Process): The carbide blank is mounted in a high-precision 5-axis CNC grinding machine. Diamond grinding wheels are used to simultaneously form all critical features in a single, continuous setup:

   • Flute Geometry: Grinding the complex helical or straight flutes for chip evacuation.

   • Point Geometry: Creating the precise chisel edge, point angle (e.g., 135°), and lip relief angles.

   • Shank: Forming the perfectly concentric cylindrical shank.
     This integrated process ensures exceptional concentricity and geometry accuracy.

3. Specialized Coating Application: The ground drill undergoes a Physical Vapor Deposition (PVD) coating process. Common coatings include:

   • TiAlN (Titanium Aluminum Nitride): For high heat and wear resistance (standard).

   • AlTiN (Aluminum Titanium Nitride): For even higher temperature performance.

   • Diamond-Like Carbon (DLC): For drilling abrasive non-ferrous materials (less common for steel).

4. Laser Marking & Final Inspection: The drill is laser-marked with size and coating information. It undergoes 100% inspection under high-power microscopes for edge sharpness, geometry, and surface defects. Critical dimensions like diameter and runout are verified with laser micrometers and air gauges.

Product Applications

• 精密 Medical Device Manufacturing: Drilling micro-holes in 316L stainless steel for surgical instruments, implant components (screws, plates), and fluidic channels in diagnostic devices.

• Electronics & Semiconductor: Drilling vias, mounting holes, and cooling channels in stainless steel housings, connectors, and precision fixtures.

• Watchmaking & Precision Mechanics: Creating pivot holes, jewel settings, and tiny screw holes in watch components and miniature mechanical assemblies.

• Aerospace & Automotive: Drilling fuel injector nozzles, sensor mounting holes, and cooling holes in turbine components or high-performance engine parts.

• Mold & Die Making: Drilling micro coolant channels (conformal cooling) in mold inserts made of hardened stainless steels.

Product Technical Parameters (Detailed Table)