Somta Series 1NA – 6.35 mm (No. 3) HSS Centre Drill

Somta Series 1NA – 6.35 mm (No. 3) HSS Centre Drill | 1NA0003

The SOMTA 1NA0003 is a High-Speed Steel Centre Drill (No. 3) engineered to American Standard Form A (60°) for precise pilot and countersink hole production prior to turning or grinding. Its rigid HSS body delivers outstanding strength, heat resistance, and wear performance, ensuring accurate, concentric centres and smooth running in all general engineering materials.

Designed for professional machining applications, this tool combines precision-ground geometry with a bright finish for clean chip evacuation and burr-free holes. Ideal for centering operations on steel, cast iron, and non-ferrous metals requiring repeatable accuracy and superior surface finish.

Key Features & Benefits

• High-Speed Steel (HSS) – Provides exceptional hardness, toughness, and resistance to heat and abrasion.
• Form A 60° Included Angle – Meets American Standard geometry for accurate pilot and countersink formation.
• Bright Finish – Reduces friction and minimises burr formation for cleaner hole edges.
• Precision-Ground Flutes – Promotes smooth chip removal and consistent hole geometry.
• Short, Rigid Construction – Ensures stability and reduces deflection during high-speed operations.

Technical Specifications

• Part No: 1NA0003
• Series: 1NA (Centre Drills – American Standard Form A)
• Tool Type: HSS Centre Drill No. 3
• Pilot Diameter (d): 2.78 mm
• Body Diameter (d₁): 6.35 mm (≈ 1/4″)
• Web Length (l₂): 2.8 mm
• Flute Length (l₁): 51 mm
• Point Angle: 60° Included Angle (Form A)
• Finish: Bright Finish
• Material: High-Speed Steel (HSS)
• Suited Materials: General engineering steels, cast irons, and non-ferrous metals

Why Choose SOMTA Cutting Tools?

• Precision Manufacturing – Built to ANSI standards for dimensional accuracy and consistency.
• Reliable Performance – Maintains tight tolerances and true centres in every operation.
• Industrial Durability – Hardened HSS construction ensures long tool life under continuous use.
• Trusted Brand Quality – Manufactured by SOMTA Tools, a leader in precision cutting since 1954.

The SOMTA 1NA0003 offers reliable accuracy, exceptional finish quality, and long-term performance for centre-drilling applications. Available through Twin Eagle Imports — your trusted source for premium industrial cutting tools and machining solutions.