Value Collection BC10P0004 Combo Drill Countersink Size 4

Product Description

The VALUE COLLECTION BC10P0004 is a combination drill and countersink designed for producing accurately sized pilot holes and countersunk seats in a single operation. Built from cobalt tool steel with a bright, uncoated finish, this right-hand-cut tool handles harder workpiece materials where standard high-speed steel wears quickly. The trade size 4 designation corresponds to a 5/16-inch body diameter with a 1/8-inch drill point diameter and 1/8-inch drill point length. Overall length is 2-1/8 inches. The 82-degree included angle is the standard for flat-head fasteners in metal fabrication and aerospace-adjacent work. Installation is performed by machinists and precision metalworkers using a lathe, drill press, or CNC machining center.

This combo drill countersink is suited for light metalworking applications where a clean, accurate countersink is required alongside a pilot hole. The double end type provides a second usable end, extending tool life before replacement is needed. The plain cutting edge style makes it straightforward to run at standard cobalt tooling speeds and feeds in steel, stainless, and other difficult-to-machine alloys. It is packaged individually and fits standard toolholders and chucks accepting this body diameter.

Key Features

• Cobalt tool steel construction for improved heat and wear resistance in hard materials
• 82-degree included angle matches standard flat-head fastener countersink geometry
• Double end design provides two usable cutting ends per tool
• Right-hand cut for use in conventional drill presses, lathes, and CNC setups
• Bright, uncoated finish for easy visual inspection of cutting edge condition
• Compact 2-1/8-inch overall length suits tight-clearance workholding setups

Compatibility

Designed as a standard trade size 4 combo drill countersink compatible with toolholders and chucks accepting a 5/16-inch body diameter shank in drill presses, engine lathes, and machining centers.

Installation Notes

This tool is typically installed and operated by machinists or precision metalworkers in a drill press, lathe, or CNC spindle. Secure the tool firmly in the chuck or collet and verify runout before cutting. Ensure the workpiece is clamped securely to prevent movement during the combined drilling and countersinking operation. Use appropriate cutting fluid or lubricant for the workpiece material to maximize tool life.