In mining, tunneling, and quarrying operations, the quality of your drilling consumables directly determines your project's productivity and cost per meter. Among all
rock drilling tool options available today,
thread button bit products remain the most widely used top hammer drilling consumables for medium to deep hole blasting applications. Selecting the right bit profile, thread size, and carbide configuration can mean the difference between a smooth drilling operation and costly downtime caused by premature wear, stuck bits, or poor penetration rates.
What Are Thread Button Bits?
A thread button bit is a drill bit designed for percussive rock drilling, featuring a threaded connection that screws directly onto a
drill rods extension or shank adapter. The bit face is embedded with multiple tungsten carbide inserts (buttons) arranged in specific patterns — gauge buttons on the outer perimeter protect the bit diameter from wear, while front buttons on the face deliver the impact energy to fracture the rock. Thread button bits are used across a wide range of applications including underground mining blast holes, tunnel face drilling, bench blasting in open-pit quarries, and rock bolt anchoring in civil engineering projects.
Unlike tapered bits that rely on a friction-fit connection, thread button bits provide a rigid, vibration-resistant coupling that transfers percussive energy more efficiently from the drill string to the bit face. This design allows for deeper hole drilling and better hole straightness, especially in fractured or abrasive rock conditions.
Common Thread Sizes and Their Applications
Thread button bits are manufactured in several standard thread profiles, each suited to specific drilling conditions and rig capacities. Choosing the correct thread size is critical for matching the bit to the drill rig's power output and the required hole diameter.
| Thread Type |
Typical Bit Diameter |
Recommended Application |
| R25 |
45mm – 65mm |
Small-scale tunneling, roof bolting, light drifting |
| R32 |
51mm – 76mm |
Medium drift development, production drilling, blast furnace tapping |
| T38 |
64mm – 89mm |
Medium-depth production blasting, hard rock mining |
| T45 |
76mm – 102mm |
Deep hole production drilling, heavy-duty quarrying |
| T51 |
89mm – 127mm |
Large-diameter bench blasting, ore mining, heavy construction |
R32 and T38 profiles are the most common choices for general mining and tunneling operations. For larger diameter holes exceeding 100mm, T45 and T51 thread sizes provide the additional torque capacity and impact resistance needed to handle the increased load from high-power hydraulic drifters.
Face Design: Flat Face, ｄｒｏｐ Center, and Retrac
The face profile of a thread button bit directly impacts flushing efficiency, penetration rate, and bit life. Three primary designs are available:
Flat Face Bits — The standard design with a flat front surface. These bits offer excellent gauge protection and are ideal for hard, competent rock formations where hole straightness is critical. The flat profile maximizes the number of front buttons for uniform impact distribution.
ｄｒｏｐ Center Bits — Feature a recessed center section that creates a natural piloting effect. The concave face helps center the bit in the hole and improves flushing in softer or fractured ground. ｄｒｏｐ center bits typically achieve higher penetration rates in broken rock conditions.
Retrac (Retractable) Bits — Equipped with an extended skirt featuring additional rear-facing carbide inserts. This design reams the borehole during bit withdrawal, clearing loose rock fragments and preventing the bit from getting stuck. Retrac bits are essential for fractured formations, loose strata, and any application where hole collapse is a risk.
How to Choose the Right Thread Button Bit
Selecting the optimal thread button bit requires evaluating several key factors to match the tool to the specific drilling environment:
- Rock Hardness and Abrasiveness: Hard, abrasive rock demands bits with larger-diameter carbide buttons and more aggressive face profiles. Softer formations benefit from bits with fewer, more widely spaced buttons to prevent clogging.
- Hole Depth and Diameter: Deeper holes require larger thread sizes (T45 or T51) to handle the increased torque and weight. Hole diameter must match the rig's capacity and the intended blasting pattern.
- Drill Rig Compatibility: The bit's thread must match the drill rod or shank adapter thread. Common rig types include hydraulic jumbos, handheld rock drills, and top hammer surface drill rigs.
- Flushing Requirements: Adequate flushing hole configuration (front and side holes) is essential for clearing cuttings and cooling the bit. Higher air or water pressure systems benefit from bits with optimized flushing port arrangements.
- Formation Stability: In fractured or collapsing ground, a retrac design is strongly recommended to prevent stuck-bit incidents and maintain hole integrity.
Complementary Rock Drilling Tools
Thread button bits work as part of a complete drilling system. For optimal performance, they should be paired with high-quality
drill rods and shank adapters that match the thread profile. MF (male-female) rods, hex rods, and extension rods with T38, T45, or T51 connections ensure consistent energy transmission from the rock drill to the bit face.
For applications requiring deeper penetration or different drilling methods,
dth drilling tool systems with down-the-hole hammers and bits provide an alternative approach. DTH tools excel in deep hole drilling where top hammer energy loss becomes significant, and are commonly used in water well drilling, foundation piling, and large-diameter quarry blasting.
Why Source Thread Button Bits from TY Drill Bits
Xi'an Heaven Abundant Mining Equipment CO.,LTD (TY Drill Bits) has been manufacturing and supplying rock drilling consumables since 2010. Based in Xi'an, Shaanxi, China, the company offers a complete range of thread button bits covering R25, R32, T38, T45, and T51 profiles in diameters from 45mm to 127mm. Each bit is produced from forged alloy steel, precision CNC machined, and fitted with high-grade tungsten carbide inserts to deliver consistent performance in demanding rock conditions.
TY Drill Bits holds ISO9001 certification and serves customers across global markets, with an export ratio exceeding 90%. The company provides OEM services, flexible payment terms including L/C, T/T, and PayPal, and maintains a lead time of within 15 working days for both peak and off seasons. With 159 products across 9 categories — including PDC bits, tricone bits, core bits, cutting tools, DTH tools, and carbide drag bits — TY Drill Bits is positioned as a one-stop supplier for drilling operations worldwide.
Looking for reliable thread button bits for your next project? Contact TY Drill Bits today to discuss your drilling requirements. Our team can recommend the optimal bit specification for your rock conditions and provide a competitive quotation. Reach us at
Lucy@tydrillbits.com or call
+86 15389082037 (WhatsApp/WeChat: gb526122709). Visit
our thread button bit product page to browse the full range of available sizes and configurations.
Xi'an Heaven Abundant Mining Equipment CO.,LTD
