R25 51mm Threaded Button Bit Dome Spherical Tungsten Carbide Hard Rock Drilling

R25 51mm Threaded Button Bit for Rock Drilling

The R25 51mm dome threaded button bit is a top hammer rock drilling tool designed for heavy-duty underground drifting, tunnelling and small-hole bench drilling in medium-to-hard rock. With a normal skirt body and a powerful 9-button configuration, this 2-inch rock bit delivers high impact resistance and exceptional gauge maintenance.

Product Overview

Engineered with six 10mm outer gauge buttons and three 9mm front buttons, the R25 51mm bit maintains a clean 51mm hole clearance while optimizing crushing energy distribution. The dome (spherical) button geometry provides excellent fatigue and wear resistance under high-impact percussive drilling conditions, while the forged alloy steel body with advanced heat treatment ensures thread toughness and anti-fatigue performance.

Main Applications

• Underground Tunnelling & Drifting: Precision hole drilling for mine development and tunnelling projects in hard rock.
• Bench Drilling: Small-hole benching and production drilling in open-pit or underground mining operations.
• Rock Bolting: Reliable drilling for roof support installation in mining and civil engineering.
• Blast Hole Drilling: The 51mm (2 inch) diameter provides larger blast holes with increased charge capacity per hole.

Key Features & Advantages

• Heavy-Duty 9-Button Layout: Six 10mm outer gauge buttons maintain a clean 51mm hole clearance, while three 9mm center buttons optimize crushing energy distribution.
• Dome / Spherical Button Geometry: Delivers high fatigue and wear resistance under high-impact percussive drilling conditions.
• High-Strength Alloy Body: Forged from premium alloy steel (42CrMo) with advanced heat treatment for thread toughness and anti-fatigue performance.
• Flushing Optimization: Balanced front and side flush holes ensure quick cuttings discharge and minimize bit binding.
• Cost-Effective Service Life: High-wear tungsten carbide grade (YK05/T6) reduces cost per meter in abrasive rock formations.

Product Specifications

FAQ

Q1: What are the main applications of an R25 51mm dome threaded button bit?
A: It is primarily used for underground tunnelling, drifting, bench drilling and bolting in medium-to-hard rock formations. The 51mm (2 inch) diameter provides a larger hole size compared to 35-45mm bits, making it ideal for blast holes that require increased charge capacity per hole.

Q2: Why is the 10mm x 6 + 9mm x 3 button configuration used for this 51mm bit?
A: This 9-button configuration is optimized for hole stability and crushing performance. Six outer gauge buttons resist extreme side wear and ensure accurate hole diameter retention, while three front buttons break down the central rock core efficiently without clogging the flush channels.

Q3: What is the advantage of dome (spherical) buttons over ballistic buttons on a 51mm bit?
A: Dome buttons offer higher impact toughness, withstand heavy percussion without chipping, perform better in hard and abrasive rock, and provide a significantly longer working life in tough rock conditions.

Q4: When should I choose a normal skirt instead of a retrac skirt for an R25 51mm bit?
A: A normal skirt is best suited for homogenous, solid rock formations where hole collapse is rare. Choose a retrac skirt if you frequently experience jammed drill rods during retraction in loose, fractured or sticky rock.

Q5: How can operators prevent premature failure on R25 51mm thread bits?
A: Regrind buttons when flat spots reach one-third of the button diameter, maintain sufficient water or air flushing pressure to clear rock dust, and monitor feed pressure to avoid thread damage or carbide fracturing.