HYMNORQ 13-Piece M35 Cobalt Steel Drill Bit Set, Metric 1.5mm - 6.5mm | Professional Grade for Hard Metals

• Premium M35 Cobalt Construction: Manufactured from High-Speed Steel containing 5% Cobalt (HSS-Co), these bits achieve a Rockwell Hardness of up to 67 HRC. This advanced composition provides superior heat and wear resistance, allowing them to cut through hard metals like stainless steel, cast iron, and titanium alloy up to 12x longer than standard HSS bits.
• Precision 135° Split Point: Features a self-centering 135-degree split point tip that penetrates hard materials immediately with less pressure. This design eliminates "walking" or wandering on the surface, ensuring a precise start without the need for a center punch or pilot hole.
• Fully Ground for Efficiency: Unlike roll-forged alternatives, these bits are fully ground from solid hardened steel. This precise manufacturing process ensures accurate diameter concentricity and sharper cutting edges. The precision-ground dual flutes provide smooth, efficient chip removal to prevent overheating.
• 13-Piece Metric Size Range: A comprehensive set covering common metric sizes for tapping and general drilling: 1.5, 2, 2.5, 3, 3.2, 3.5, 4, 4.5, 4.8, 5, 5.5, 6, and 6.5mm. Includes specific sizes often required for rivets or pre-threading holes (e.g., 3.2mm, 4.8mm).
• Professional Metal Index Case: Housed in a durable, heavy-duty red metal index case rather than plastic. The case features a clearly labeled metal holder that tilts out for easy access and organization, protecting the bits from damage during transport and storage in rough workshop environments.

• Select the Correct Bit Size — Choose the metric drill bit from the 13-piece set that matches your required hole diameter (1.5mm to 6.5mm). Ensure the shank fits securely in your drill chuck or collet.
• Prepare for Drilling — For hardened metals like stainless steel or cast iron, apply a suitable cutting fluid or oil to the drilling area and the bit. Set your drill to the appropriate RPM for the material and bit size.
• Drill the Hole — Position the bit on your marked spot. The 135° split point will self-center. Apply steady, moderate pressure. Allow the bit to cut without forcing. Use the precision-ground flutes to clear chips efficiently.
• Clean and Store — Once drilling is complete, remove the bit and clean any metal shavings. For maximum longevity, store the bits in their original, labeled metal index case to protect them from damage and corrosion.

Typical situations where HYMNORQ 13-Piece M35 Cobalt Steel Drill Bit Set helps — illustrative scenarios, not customer reviews.