Down the hole Flat Face Drill Bit – 4 Inch

A Flat Face Down-The-Hole (DTH) Bit is a percussion drilling tool used in DTH hammers to crush and cut rock at the bottom of a borehole. It transfers impact energy from the hammer piston directly to the rock through tungsten carbide buttons, while compressed air removes the crushed cuttings. The flat face design means the front of the bit is planar (flat) not concave or convex. This geometry provides balanced energy transfer and excellent hole direction control.

Design:

• Bit Face Geometry – Flat face with multiple air/flushing holes. Offers uniform impact distribution across all buttons. Ensures straight hole drilling and high stability. Slightly slower penetration rate compared to convex types but provides better control and bit life in hard, compact rocks.
• Button Configuration – Tungsten carbide buttons arranged in concentric or symmetrical patterns. Spherical buttons for hard and abrasive rock (resist wear and breakage). Semi-ballistic buttons may be used for slightly softer rock to increase penetration rate.
• Flushing System – Air holes located between buttons or near the center of the bit. High-pressure air flows through these holes to remove rock chips, cool the bit, and prevent clogging.
• Shank Design – Lower part of bit includes a splined shank that connects to the DTH hammer. Common shank types: SD, QL, Mission, COP, DHD, etc. Designed for precise fit to ensure efficient energy transfer.
• Bit Body – Cylindrical or slightly tapered body for stability and durability. External diameter corresponds to the required borehole size (typically 3″ to 12″ or larger).

Applications:Designed for medium to hard rock formations, Convex Face DTH Bits are ideal for:

• Mining and quarrying operations
• Water well and geothermal drilling
• Construction and foundation works

Materials:

• Bit Body: High-strength alloy steel (e.g., 40CrNiMo, AISI 4140, or 4340) – High impact toughness, fatigue resistance, and machinability.
• Buttons/Inserts: Tungsten carbide (WC-Co composite) – Extreme hardness (HRA 8892), high wear resistance, excellent impact strength.
• Heat Treatment: Carburizing, quenching, tempering, and shot peening – Increases surface hardness (5060 HRC) and fatigue life.
• Surface Treatment: Black oxide, phosphate coating, or anti-corrosion plating – Corrosion resistance and wear protection.