Drill Countersink Set GEKO G38574 for Metal, 6.3–20.5 mm, 6 pcs, HEX

Set of GEKO metal countersinks G38574, comprising six HEX-shank tools covering sizes from 6.3 mm to 20.5 mm. These countersinks are designed for countersinking, chamfering and enlarging holes in a variety of metal workpieces. The HEX shank ensures secure fit in standard HEX chucks and quick bit changes, making the set suitable for workshop, maintenance and fabrication environments where reliable hole finishing is required.

Advantages

The set provides a range of diameters in a compact kit, reducing the need to switch individual tools for common hole sizes. HEX shanks deliver improved grip and reduce slippage in compatible chucks. Each tool is optimized for metalworking, offering controlled material removal for clean chamfers and reduced burr formation. The assortment supports both manual and powered operations, enabling consistent results across different drilling setups.

Suitable for

• Countersinking holes in steel, aluminum and other metals
• Deburring and chamfering cut or drilled holes
• Enlarging pilot holes to match fastener head profiles
• Workshop maintenance and on-site repair tasks
• Fabrication and assembly operations requiring precision hole finishing

Key specifications

• Material suitability: metal (steel, aluminum and similar alloys)
• Shank type: HEX shank for secure chuck engagement
• Range of diameters: 6.3 mm to 20.5 mm (six sizes included)
• Quantity in set: 6 pieces
• Typical applications: countersinking, chamfering, deburring, hole enlargement

How to use

Select the countersink size appropriate for the hole diameter and intended chamfer. Secure the HEX shank in a compatible chuck, ensuring firm clamping to prevent wobble. Position the countersink coaxially with the existing hole, apply steady, even pressure and operate at a moderate rotational speed suitable for the workpiece material. Withdraw periodically to clear chips and inspect the chamfer until the desired edge profile is achieved. When finished, clean the cutting edges and store the tools in their kit to protect against damage.

Usage recommendations

Use cutting fluid or lubricant with harder metals to extend tool life and improve surface finish. Avoid excessive feed pressure and very high speeds that may cause premature wear. For best results, match countersink diameter to fastener head geometry and verify alignment before final chamfering.