OSG EX-GDN TiN Coated Cobalt HSS Twist Drill for 4×D Deep Hole Drilling in Carbon Steel

The OSG EX‑GDN is a medium‑length cobalt high‑speed steel (HSS‑Co) drill from OSG (Japan), part of the EX‑GOLD series. It is designed for high‑speed, non‑step drilling up to 4× diameter in general carbon steel, alloy steel, and cast iron, even in small diameters. Featuring a TiN coating, 130° point angle, and 30° helix angle, it delivers good wear resistance, stable chip evacuation, and long tool life in general‑purpose CNC and manual drilling.

• Medium Flute Length: Between stub and regular, enables 4×D deep hole drilling without step‑down.
• Cobalt HSS Substrate: High hardness and heat resistance for continuous cutting in steels.
• TiN Coating: Reduces friction, improves wear resistance, and extends tool life.
• 130° Point Angle: Self‑centering, low thrust force, suitable for most steels.
• 30° Helix Angle: Balanced rigidity and chip space for smooth chip flow.
• Four‑Facet Thinning: Enhances centering and reduces cutting load (for Dc ≤1.5 mm: X‑form).
• h7 Shank Tolerance: Compatible with standard drill chucks and tool holders.

• Carbon steels (1045, S355, Q235) – primary
• Alloy steels (4140, 42CrMo4, SCM series) – highly recommended
• Cast iron (HT200, HT250, FC series) – optimized
• Tool steels (SKD, SKS, ≤35 HRC)
• Aluminum alloys & copper (light cuts)
• Heat‑treated steels (≤35 HRC)

• General‑purpose drilling in carbon/alloy steels and cast iron
• Non‑step high‑speed drilling up to 4× diameter
• Small‑diameter precision drilling (φ0.5–φ3.9 mm)한국OSG주식회사
• CNC drilling and manual drilling operations
• Mass production in automotive, hydraulic, and general engineering

As a versatile medium‑length drill for steel and cast iron, it combines cobalt HSS toughness, TiN wear resistance, and 4×D non‑step drilling capability for stable performance and low cost. OSG’s Japanese precision ensures consistent quality for general‑purpose production.