Drill Bits for Stainless Steel Cable Trays

Cobalt drill bits (M35 or M42) are the most effective choice for drilling stainless steel cable trays, offering durability, heat resistance, and clean cuts.

Best Drill Bit Types for Stainless Steel

Cobalt Drill Bits (M35 & M42)

• Made from high-speed steel with 5–8% cobalt content, providing excellent heat resistance and hardness.
• Ideal for repeated drilling in stainless steel cable trays and other hard metals.
• Can be resharpened and used with hand drills or drill presses for precision work . Titanium-Coated HSS Bits
• Budget-friendly option with a titanium nitride (TiN) coating.
• Suitable for occasional drilling but the coating wears off with repeated use . Carbide-Tipped Drill Bits
• Extremely hard and wear-resistant, best for industrial or high-volume applications.
• Brittle under hand-held drills, so mainly recommended for drill presses . Step Drill Bits
• Useful for creating multiple hole sizes without changing bits.
• Effective for thinner stainless steel panels but can generate heat on thicker trays .

Key Features to Consider

• Bit Material: Cobalt or carbide for durability; titanium-coated HSS for light-duty work .
• Tip Angle: 118° or 135° split-point tips prevent slipping and reduce heat buildup .
• Flute Design: Spiral flutes help remove chips efficiently, reducing overheating .
• Length: Shorter bits are sturdier; extra-long bits allow access in tight spaces but require careful handling .

Drilling Techniques for Stainless Steel Cable Trays

1. Use Cutting Oil: Reduces friction and heat, prolonging bit life .
2. Slow and Steady Speed: 600–800 RPM is recommended to prevent work-hardening .
3. Pilot Holes: Start with a smaller bit to guide the final hole.
4. Clear Chips Frequently: Lift the bit periodically to remove metal shavings.
5. Cool Between Drills: Let bits cool or dip in water to avoid overheating.
6. Center Punch: Mark the drilling spot to prevent bit wandering .

Cable-Specific Installer Bits

For routing cables through trays, flexible installer or auger bits are useful:

• Flexible drill bits with screw-point or fish-eye tips allow wire pulling through walls, ceilings, and conduits .
• Snakebit or hollow-shank bits can be used for precise cable installation in tight spaces .

Recommended Drill Bit Sets

• Irwin 29-Piece Cobalt Alloy Steel M-35 Drill Bit Set: Best overall for stainless steel, heat-resistant, and resharpenable .
• DeWalt Industrial Cobalt Alloy Steel Set: Durable, includes pilot points and 3-flat shank for secure chucking .
• Comoware Cobalt 15-Piece Twist Drill Bit Set: Affordable, versatile, and suitable for DIY or light commercial use . Using the right bit and proper technique ensures clean, precise holes in stainless steel cable trays while extending the life of your drill bits and reducing frustration during installation.