Irwin 1877720 3PC High Speed Steel Black Oxide Countersink Drill Bit Set (1/2″, 5/8″, 3/4″)

The Irwin 1877720 3-Piece High Speed Steel Black Oxide Countersink Drill Bit Set includes the three most commonly used countersink sizes for flat-head fastener applications. Designed for clean, accurate countersinking across a range of machinable materials, this set provides a convenient solution for users who need versatility without purchasing individual bits. Each countersink is manufactured from industrial-grade high speed steel for reliable cutting performance and long service life.

All three countersinks feature a precision ground 82-degree cutting angle, which matches the standard profile used for most flat-head screws in metal, wood, and plastic. A multi-flute cutting design helps reduce vibration and chatter, producing smoother results and better control during operation. The black oxide finish adds corrosion resistance and reduces friction while cutting. With standard 1/4-inch round shanks, each bit is compatible with most handheld drills and drill presses, making this set suitable for shop, jobsite, and maintenance use.

Irwin 3PC High Speed Steel Black Oxide Countersink Drill Bit Set At a Glance

• 3-Piece Set: Covers the most common countersink sizes
• Included Sizes: 1/2″, 5/8″, and 3/4″ diameters
• 82° Cutting Angle: Matches standard flat-head fastener profiles
• High Speed Steel Construction: Built for durability and consistent cutting
• Multi-Flute Design: Reduces vibration for smoother operation
• Black Oxide Finish: Improves corrosion resistance and cutting efficiency
• 1/4″ Round Shanks: Fits most drills and drill presses

Markets

• Metal Fabrication Shops: Used for preparing fastener holes in steel and aluminum
• Construction and Renovation: Ideal for hardware installation and structural fastening
• Woodworking and Carpentry: Provides clean countersinks for framing and finish work
• Automotive and Equipment Repair: Supports flush fastener installation on panels and brackets
• Maintenance and Facility Services: Covers multiple countersink sizes for daily repairs
• Trade Schools and Educational Programs: Useful for teaching countersinking techniques

Having the right countersink size on hand helps reduce downtime and improve finished results. The Irwin 1877720 countersink drill bit set provides three commonly used sizes in one package, allowing users to handle a wide range of fastening applications without switching tools or sourcing additional bits. From smaller hardware to larger flat-head fasteners, this set supports consistent, flush seating across metal, wood, and plastic.

Each countersink is built from high speed steel and finished with a black oxide coating to support durability in shop and jobsite conditions. The 82-degree cutting angle aligns with standard fastener designs, helping reduce rework and improve overall appearance. For contractors, fabricators, and maintenance crews who need versatility and reliability, this countersink set offers a practical, ready-to-use solution.

Irwin 1877720 3PC High Speed Steel Black Oxide Countersink Drill Bit Set (1/2″, 5/8″, 3/4″) Features

• Industrial-Grade High Speed Steel: Provides strength and wear resistance for repeated use
• Precision Ground 82° Tip: Designed for standard flat-head fastener applications
• Five-Flute Cutting Geometry: Reduces vibration and improves cut quality
• Black Oxide Coating: Helps resist corrosion and reduce friction during cutting
• Machinable Material Compatibility: Suitable for iron, steel, soft metals, plastics, and wood

Irwin 1877720 3PC High Speed Steel Black Oxide Countersink Drill Bit Set (1/2″, 5/8″, 3/4″) Includes

• (1) 1/2″ High Speed Steel Countersink Drill Bit
• (1) 5/8″ High Speed Steel Countersink Drill Bit
• (1) 3/4″ High Speed Steel Countersink Drill Bit

Irwin 1877720 3PC High Speed Steel Black Oxide Countersink Drill Bit Set (1/2″, 5/8″, 3/4″) Specifications

• Number of Pieces: (3)
• Included Diameters: 1/2 in., 5/8 in., 3/4 in.
• Cutting Angle: 82 Degrees
• Shank Size: 1/4 in.
• Shank Type: Round
• Material: High Speed Steel
• Finish: Black Oxide

Why Customers Choose the Irwin 3PC High Speed Steel Black Oxide Countersink Drill Bit Set

Customers choose the Irwin 1877720 countersink drill bit set because it combines the most commonly used countersink sizes into one convenient package. The high speed steel construction delivers reliable cutting performance across multiple materials, while the black oxide finish helps extend tool life in demanding shop and jobsite environments. Each countersink features an 82-degree cutting angle that matches standard flat-head fasteners, helping ensure clean, flush seating without additional finishing.

With three sizes ready for use and standard 1/4-inch shanks for broad compatibility, this set reduces tool changes and improves efficiency. For professionals and advanced DIY users who want dependable countersinking performance across a range of fastening tasks, this Irwin set offers practical versatility and consistent results.