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Makita 3-1/8in x 24in SDS MAX Tunnel Bit
- $224.00
- Brands Makita
- Product Code: B-66313
- Availability: In Stock
Makita 3-1/8 In. x 24 In. SDS-MAX Tunnel Bit – B-66313 The Makita B-66313 3-1/8 In. x 24 In. SDS-MAX Tunnel Bit is a specialized masonry drilling accessory designed for creating large, deep through-holes in concrete, brick, and block. It is particularly useful when installing piping, ventilation systems, electrical conduit, and other services where the hole depth exceeds the capability of a conve..
Makita SDS MAX 3-1/8in x 24in Tunnel Bit for Concrete
Makita 3-1/8 In. x 24 In. SDS-MAX Tunnel Bit – B-66313
The Makita B-66313 3-1/8 In. x 24 In. SDS-MAX Tunnel Bit is a specialized masonry drilling accessory designed for creating large, deep through-holes in concrete, brick, and block. It is particularly useful when installing piping, ventilation systems, electrical conduit, and other services where the hole depth exceeds the capability of a conventional core bit.
Its solid tungsten carbide head, asymmetrical carbide teeth, and two-flute design are engineered to provide efficient material removal while helping clear debris from the hole. The integrated carbide-tipped centering point also helps reduce bit walking during initial penetration, making it easier to start an accurate hole.
Key Features
- 3-1/8-inch drilling diameter: Creates large-diameter holes for utility and building-service installations.
- 24-inch overall length: Provides extended reach for deep drilling applications.
- 18-inch usable length: Offers substantial drilling depth for through-hole work.
- SDS-MAX shank: Designed for use with compatible SDS-MAX rotary hammers.
- Solid tungsten carbide head: Provides a durable cutting structure for concrete, brick, and block.
- Asymmetrical tungsten carbide teeth: Designed to improve drilling efficiency and extend cutting life.
- Two-flute design: Helps move drilling debris out of the hole more efficiently.
- Carbide-tipped centering point: Helps reduce bit walking and improves starting accuracy.
- One-piece construction: Transfers impact energy directly toward the cutting end of the bit.
- Large-diameter capability: Allows compatible rotary hammers to produce larger holes than standard carbide bits.
- Deep-hole capability: Designed specifically for applications where a standard core bit does not provide sufficient depth.
Product Specifications
| Specification | Details |
|---|---|
| Model | B-66313 |
| Product Type | SDS-MAX Tunnel Bit |
| Diameter | 3-1/8 in. |
| Overall Length | 24 in. |
| Usable Length | 18 in. |
| Shank Type | SDS-MAX |
| Cutting Head | Solid Tungsten Carbide |
| Flute Design | Two Flute |
| Centering Point | Carbide-Tipped |
| Application Material | Concrete, Block, Brick |
| Package Quantity | 1 |
| Shipping Weight | 5.8 lbs. |
| UPC | 088381-539173 |
Specifications are based on Makita's published information for the B-66313.
Designed for Deep Through-Holes
The B-66313 is intended for situations where a large hole must extend deeper into masonry than a standard core bit can reach. Its 18-inch usable length makes it well suited to through-holes for building services such as pipes, ventilation ducts, and electrical installations.
The tunnel-bit design is also different from a conventional short core bit. Makita's two-flute configuration helps evacuate debris as drilling progresses, while the asymmetrical carbide teeth are designed to reduce inefficient cutting behavior and support longer bit life.
Recommended Applications
The Makita B-66313 is suitable for:
- Drilling deep holes through concrete
- Drilling brick and concrete block
- Plumbing pipe penetrations
- Electrical conduit installations
- Ventilation installations
- Building-service through-holes
- Construction and renovation work requiring large-diameter masonry penetrations
Compatibility
This tunnel bit is designed for rotary hammers that accept SDS-MAX bits. Makita specifically identifies its SDS-MAX rotary hammer platform for this accessory.
Makita recommends using Rotary Hammer Bit Grease 194683-7 with its SDS-MAX tunnel drill bits.
What's Included
- 1 × Makita B-66313 3-1/8 In. x 24 In. SDS-MAX Tunnel Bit
Why Choose the Makita B-66313?
The Makita B-66313 is a purpose-built solution for contractors who need to drill large, deep holes in masonry. Its combination of a 3-1/8-inch diameter, 18-inch usable length, solid carbide head, centering point, asymmetrical teeth, and two-flute debris-clearing design makes it well suited to demanding installation work.
For applications involving concrete, block, or brick penetrations, this tunnel bit provides the reach and cutting geometry needed when a standard short core bit is not deep enough.