Drill bit set Forsage 3.9 mm HSS+Co for metal, 10 pcs

Forsage 3.9 mm HSS+Co drill bit set for metal, 10 pcs is a compact assortment of high-speed steel bits alloyed with cobalt, intended for drilling metal materials. Each bit has a nominal diameter of 3.9 mm and a geometry suited for cutting ferrous metals. The set contains ten identical pieces, offering replacements and repeatable performance for workshop tasks, maintenance work and light fabrication jobs.

Advantages

The HSS+Co composition increases heat resistance and maintains hardness at elevated drilling temperatures, reducing wear during repeated use. The consistent 3.9 mm diameter ensures uniform hole sizes across multiple pieces. These bits are manufactured to provide stable cutting action in thin and medium-thickness metal sheets and other ferrous materials, helping to maintain drilling speed and reduce the need for frequent resharpening.

Suitable for

• Drilling holes in steel sheets and metal plates
• Workshop maintenance and repair tasks
• Light fabrication and assembly where 3.9 mm holes are required
• Preparing pilot holes in ferrous materials before tapping or fastening

Key specifications

• Material: high-speed steel with cobalt alloy (HSS+Co)
• Diameter: 3.9 mm
• Quantity: 10 pieces per set
• Intended material: ferrous metals and metal sheets
• Tip/point type: standard twist drill geometry for metal

How to use

Secure the workpiece and select an appropriate drill chuck or collet that accepts the shank size of these bits. Use a drill press or hand drill at recommended speeds for HSS+Co bits when working with steel and other ferrous materials; start at a moderate speed and adjust according to material thickness and drilling performance. Apply cutting fluid or lubricant to reduce heat and improve chip evacuation. Remove chips periodically and allow the bit to cool when drilling multiple holes to preserve cutting edge life.

Usage recommendations

For best results, use a drill press for accurate, perpendicular holes and consistent feed pressure. When drilling harder steels or thicker sections, reduce speed and increase lubrication. Store the set in a dry place and inspect bits for wear or damage before use; replace worn bits to avoid poor hole quality and increased load on the drill.