Hertel 331-002070 Countersink 3/16 in 90 Degree Single Flute

Product Description

The HERTEL 331-002070 is a single-flute countersink designed for creating chamfered entry holes in metal and composite materials. With a 3/16 inch head diameter and a 90-degree included angle (45-degree centerline angle), it produces clean, accurate countersunk seats for flat-head fasteners. The straight-cylindrical shank is also 3/16 inch in diameter, making it compatible with standard drill chucks and collet holders. The bright, uncoated alloy steel construction provides solid cutting performance without a coating that could chip or flake under heavy use. Machinists, tool-and-die workers, and metalworking professionals typically use this tool in drill presses, CNC machines, or hand drills.

This countersink is suited for use on alloy steel, cast iron, and glass-reinforced plastic (GRP/fiberglass). Its single-flute geometry reduces chatter and produces a smoother finish on harder materials compared to multi-flute designs. It is appropriate for both production environments and maintenance or repair work where a consistent, flat-head fastener seat is required. The compact 3/16 inch head diameter makes it practical for small-diameter hole applications where larger countersinks would be impractical.

Key Features

• 3/16 inch head diameter with matching 3/16 inch straight-cylindrical shank
• 90-degree included angle for standard flat-head fastener seating
• Single-flute design reduces chatter on alloy steel and cast iron
• Bright, uncoated alloy steel construction for durability without coating delamination risk
• Right-hand cut for use in standard forward-rotating spindles
• No pilot included — functions as a standalone countersink for flexible use

Compatibility

Rated for use on alloy steel, cast iron, and glass-reinforced plastic. Designed as an OEM-style single-flute countersink for use in drill chucks or collet holders accepting a 3/16 inch straight shank.

Installation Notes

Installation is performed by machinists or metalworkers using a drill press, lathe, or CNC machining center. Secure the shank firmly in a drill chuck or collet before operation and verify spindle rotation is set to right-hand (clockwise) before engaging the workpiece. Always clamp the workpiece securely to prevent movement during countersinking. Use appropriate cutting fluid or lubrication when working with harder alloy steels to extend tool life.