Drillco construction reamer details
Drillco 1 Spiral Flute 1/2 Shank Nitro Construction Reamer (427N164)
Drillco 427N164 1 Spiral Flute 1/2 Shank Nitro Construction Reamer is designed for heavy-duty reaming in structural steel fabrication, bridgework, and assembly applications. This Nitro construction reamer features a tapered point with a black and gold surface treatment that provides a hard protective layer, increasing hardness without brittleness while delivering maximum lubricity. The spiral flute design enhances chip removal, reduces heat buildup, and ensures precise, clean hole enlargements. Made from premium-grade cobalt high-speed steel (HSS), it can drill harder materials approximately 30% faster than standard HSS. The self-centering 135° split-point minimizes walking and lowers thrust for stable, controlled cutting, while the shorter screw-machine length adds rigidity to reduce breakage. The 3-flats reduced shank ensures a secure, slip-free grip in the chuck.
1-inch Nitro spiral flute construction reamer with 1/2-inch shank
Black and gold Nitro surface treatment for hardness and maximum lubricity
Tapered point for smooth entry into misaligned or undersized holes
Spiral flutes for efficient chip removal and consistent cutting
Premium-grade cobalt HSS for harder materials and faster cutting
Self-centering 135° split-point minimizes walking and reduces thrust
Short screw-machine length for added rigidity and reduced breakage
3-flats reduced shank prevents slipping in the chuck
Ensures precise, clean, and smooth hole enlargements
Handles harder materials efficiently and faster than standard HSS
Maximizes tool life and cutting performance with Nitro surface treatment
Prevents tool wander for improved drilling stability
Durable construction minimizes replacement frequency and downtime
Technical Specifications:
Shank Size: 1/2 inch
Shank Type: 3-flats reduced shank
Point Type: Tapered point, 135° split-point
Flute Type: Spiral flutes
Material: Premium-grade cobalt HSS
Surface Treatment: Black and gold Nitro coating for hardness and lubricity
Length Type: Short screw-machine length
Manufacture: Made in USA
Applications: Structural steel fabrication, bridgework, assembly, hole alignment, hard material reaming
Product identification
- Brand: Drillco
- Model / MPN: 427N164





