Drill Bits

Selecting the Right Substrate: HSS vs. M35 Cobalt

For high-tensile metals like stainless steel and iron, standard carbon steels fail quickly due to heat. Industrial operations rely on M35 Cobalt (HSS-Co) containing 5% cobalt to maintain hardness at elevated temperatures. For lighter materials like aluminum, brass, and plastics, standard High-Speed Steel (HSS) or W6542 HSS provides excellent sharpness and flexibility without the higher cost of cobalt.

• M35 Cobalt (HSS-Co): Best for stainless steel, hardened metals, and continuous production. Typically features a 118-degree or 135-degree split point to prevent walking.
• Standard HSS / W6542: Optimal for aluminum and plastics. Highly resilient against lateral breakage in handheld operations.

Matching Bit Geometry and Shank Designs to the Application

Standard twist drills work well for deep cylindrical holes, but specialized geometries solve specific production challenges. A step drill bit allows operators to drill multiple hole diameters (from 3mm up to 32mm) in sheet metal using a single tool, eliminating frequent bit changes. For large-diameter penetrations up to 200mm, bi-metal hole saws with threaded mounts provide the stability needed for heavy machinery.

• Straight and Round Shanks: Ideal for standard keyed or keyless chucks in stationary drill presses.
• Hex Shanks (e.g., 1/4-inch / 3-13mm): Prevent slippage under high torque and allow quick changes in impact drivers.
• Triangle Shanks: Provide three positive contact points for high-torque drilling in larger step-bit sizes.
• M14 Threaded Mounts: Designed for direct attachment to angle grinders, common in heavy-duty diamond tile chamfering.

Sizing and Length Considerations for Precision and Deep-Hole Work

Choosing the correct diameter range is critical for maintaining structural integrity. Micro-drilling in electronics manufacturing and precision watch repair requires precision HSS sets ranging from 0.2mm to 1.6mm. For deep-reach applications where standard jobber lengths cannot reach, 150mm extra-long HSS bits provide the necessary clearance without sacrificing concentricity.

When working on hard masonry, stone, or ceramic tile, standard cutting edges will dull instantly. Utilizing a specialized masonry drill bit or a diamond-grit chamfering tool (such as 38mm to 50mm beveling bits) ensures clean edges without fracturing the brittle base material.