R25 35mm Threaded Button Bit Dome Spherical Tungsten Carbide Rock Drilling Tool
R25 35mm Threaded Button Bit for Rock Drilling
The R25 35mm dome threaded button bit is a top hammer rock drilling tool engineered for underground drifting, tunnelling and small-hole bench drilling operations. Featuring a normal skirt body and 7 durable spherical tungsten carbide buttons, this rock bit offers high impact toughness, smooth energy transfer and a long service life in medium to hard rock formations.
Product Overview
Equipped with 5 gauge buttons (7mm) and 2 front buttons (7mm), the R25 35mm bit maintains a consistent 35mm hole diameter while improving penetration rates. The dome (spherical) button profile provides high resistance to breakage and wear under high-impact percussion drilling, and the precision-machined, heat-treated alloy steel body ensures strong fatigue resistance and thread longevity.
Main Applications
- Underground Tunnelling & Drifting: Efficient hole drilling for mine development and tunnelling projects in medium to hard rock.
- Small-Hole Bench Drilling: Production drilling in open-pit or underground mining operations.
- Rock Anchoring: Fast and stable drilling for roof support and anchor installation in mining and civil engineering.
- Light-to-Medium Rigs: Easy integration with light-to-medium hydraulic or pneumatic rock drills.
Key Features & Advantages
- Optimized 7-Button Layout: Five 7mm gauge buttons ensure accurate hole diameter retention, while two 7mm center buttons improve penetration rates.
- Dome / Spherical Button Profile: Provides high resistance to breakage and wear under high-impact percussion drilling.
- Heat-Treated Alloy Steel Body: Precision machined and heat-treated body delivers high fatigue resistance and thread longevity.
- Standard Flushing Design: Efficient cuttings removal prevents re-drilling and prolongs bit life.
- Broad Rig Compatibility: R25 thread connection works with top hammer rigs.
Product Specifications
| Thread Connection | R25 |
| Bit Diameter | 35 mm (1 3/8 inch) |
| Button Type | Dome / Spherical |
| Button Configuration | 7 Buttons: Gauge 7mm x 5 + Front 7mm x 2 |
| Skirt Type | Normal / Standard Skirt |
| Face Design | Flat Face / Standard Flush |
| Body Material | High-Strength Alloy Steel (42CrMo Equivalent) |
| Carbide Grade | High-Wear Tungsten Carbide (YK05/T6) |
| Primary Application | Underground Tunnelling, Drifting, Bench Drilling in Hard Rock |
Dome vs Ballistic Buttons
| Feature | Dome / Spherical Buttons | Ballistic / Parabolic Buttons |
| Shape Profile | Rounded dome shape | Pointed, conical profile |
| Primary Advantage | High wear resistance & high impact toughness | Fast initial penetration rate |
| Failure Risk | Low risk of button fracturing | Higher risk of shearing in hard rock |
| Recommended Rock | Hard to abrasive rock, fractured formations | Soft to medium-hard non-abrasive rock |
FAQ
Q1: What are the main applications of the R25 35mm dome threaded button bit?
A: It is primarily designed for underground drifting, tunnelling, small-hole bench drilling and anchoring in medium-to-hard rock formations. The R25 thread connection integrates with light-to-medium hydraulic or pneumatic rock drills.
Q2: Why is the 7-button 7mm configuration used for this R25 35mm bit?
A: Five outer gauge buttons protect the outer diameter from excessive gauge wear and maintain a consistent 35mm hole diameter, while two inner front buttons effectively shatter the rock core at the center of the hole.
Q3: How do I choose between a normal skirt and a retrac skirt for an R25 35mm bit?
A: A normal skirt is suitable for general drilling in stable, solid rock, being lightweight and cost-effective with smooth energy transfer. A retrac skirt is designed for fractured, loose or sticky rock to prevent the drill string from jamming during retraction.
Q4: How can I extend the service life of an R25 35mm thread rock bit?
A: Regrind buttons when flat spots reach one-third of the button diameter, ensure adequate air or water flushing pressure to clear cuttings, and maintain correct feed force to prevent thread fatigue failure or premature button breakage.
Get in Touch
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