1/4″ hex shank countersinks are fine for a quick drill. They don't slip in drill chucks. You can make deep countersinks easily by setting the countersink's depth stop to allow the countersink to drill more deeply into the worksurface.
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M35 Cobalt 4-Flute Step Drill Bit 1/4 in Metric Tapered Hex Shank for Stainless Steel Sheet Metal Wood Aluminum and Other Metals
Aliexpress UK
Uses High Speed Steel 6542 material, higher hardness, more durable,can be used for drilling the steel plate even the 2mm 304 steel plate. Repellat cum officiis aspernatur numquam minus quaerat?. Titanium Coated, rust-proof.
eBay
16PCS Hole Saw Set - 19-64mm Bi-Metal Hole Saw, Mandrels Drill Bits Installation Plate Hex Key, for Wood Metal Plywood PVC Board
Aliexpress UK
1/4″ hex shank countersinks are fine for a quick drill. They don't slip in drill chucks. You can make deep countersinks easily by setting the countersink's depth stop to allow the countersink to drill more deeply into the worksurface.
eBay
Hole Saw Set 12-100mm Hard Metal Drill Bits Heavy Duty Hole Opener Hole Cutter For Metal Stainless Steel Iron Wood Plastic Etc.
Aliexpress UK
Material: High Speed Steel HSS (4241). Shank type: round. 6x Drill Bit. -Used in hardness 25 ° below the workpiece, such as carbon steel, sheet iron, insulation board.
eBay
Premium Countersink Deburring Hand Reamer Set Metal Handle with 90° Countersink Bit for Metal Wood Plastic Precision Hand Reamer
Aliexpress UK
5x High Speed Countersink Drill Bit Set Deburring Chamfering Bit for Metal, Wood.
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Hole Saws 1PC 20mm-200mm M42 Bi-Metal Drill Bit Cutter Carpentry Tools Cutting Metal Plastic Iron Hand Tools
Aliexpress UK
This Center Drill Bit Set features a 60-degree angle countersink design suitable for various materials like wood, stainless steel, aluminium, iron, nickel, brass, copper, and steel. Angle: 60-Degrees.
eBay
M42 BI -Metal Wood Hole Saws Bit Tooth Cutting For Metal Plastic Fiberboard 1PC 20mm-200mm Hole Saws
Aliexpress UK
6x Drill Bit. Shank type: round.
eBay
DT-DIATOOL Diamond Drill Bits Hole Saw Drill Core Bit for Tile Ceramic Porcelain Tile Crowns M14 Diamond Core Bit
Aliexpress UK
1/4″ hex shank countersinks are fine for a quick drill. They don't slip in drill chucks. You can make deep countersinks easily by setting the countersink's depth stop to allow the countersink to drill more deeply into the worksurface.
eBay
DEWALT DWA2PH2SL DT70547T DWASLVMF2 Phillips Magnetic Bits Set Impact Driver Drill Bit Pivoting Magnetic Bit
Aliexpress UK