Top Hammer Drill Bit

A: It is the final rock-breaking tool matched with top hammer drilling systems. It connects with top hammer drill rods, receives impact energy and rotary torque from the drill rig, and breaks rock via tungsten carbide buttons. It is widely used for blasting holes, bolt holes and foundation drilling in medium and hard rock formations.

A: According to the face design, mainstream types include concave face, flat face and convex face bits. According to specifications, they are mainly divided into thread bits (R32, R38, T38, T45, T51) matching corresponding drill rod threads, covering hole diameters from 32mm to 115mm for different drilling depth and rock hardness.

A: 1. Concave face bit: Good centering performance, suitable for fractured, broken rock and tunneling anchoring, ensures straight drilling holes; 2. Flat face bit: High rock-breaking efficiency, ideal for medium-hard and uniform rock, suitable for mass blasting hole drilling; 3. Convex face bit: Strong wear resistance and impact resistance, perfect for extremely hard and high-abrasive granite and hard basalt.

A: The core factors include rock hardness and abrasiveness, drilling flushing effect, feed pressure and impact pressure of the drill rig, thread matching degree with drill rods, and whether the bit is used with bent drill strings. Standard service life: 80–150 drilling hours for medium rock, 30–80 hours for hard abrasive rock.

A: Common reasons: 1. Tungsten carbide buttons are worn, blunt or partially fallen off, resulting in reduced rock-breaking capacity; 2. Insufficient air/water flushing causes rock debris accumulation, blocking the drilling hole; 3. Mismatched thread leads to energy loss; 4. Excessively low rig impact pressure or unreasonable feed speed. Solutions: Replace worn bits, check flushing system, and adjust rig parameters.

A: 1. Improper operation: starting drilling on uneven rock with full impact, sudden vibration and impact load; 2. Serious hole collapse and rock debris jamming causing stuck bit; 3. Unqualified bit brazing process leading to insufficient bonding strength; 4. Overused blunt bit with continuous high-impact drilling. It is recommended to replace blunt bits in time and adopt low-impact collaring.

A: It is not recommended. Although the nominal thread models (such as T38, R32) are the same, different manufacturers have slight differences in thread tolerance, shoulder angle and pitch. Mixed use will cause poor fitting, thread galling, serious energy loss, and even early damage to bits and rods.

A: Replace the bit immediately if any of the following conditions occur: 1. Tungsten carbide buttons are severely worn, flattened or missing; 2. Bit body has cracks, deformation or edge collapse; 3. Drilling efficiency drops sharply with normal rig parameters; 4. Threads are severely worn, galling and unable to connect tightly.

A: The difference lies in the bottom hole flushing hole design. Air flushing bits have larger and more flushing holes, suitable for dry drilling in open-air quarry and dry tunnel working conditions; water flushing bits have optimized small flushing holes, which can bear water pressure, reduce mud accumulation, and are suitable for underground mines and wet drilling environments with strict dust control.

A: 1. Store in a dry and ventilated warehouse, avoid long-term moisture and rust on threads and bit body; 2. Coat anti-rust grease on threads and install protective caps for idle bits; 3. Avoid violent collision and extrusion to prevent alloy tooth damage and bit deformation; 4. Clean rock debris and dirt after use, and inspect thread and button status regularly.