



DCDMA Standard Casing Tube for Core Drilling
Standard: DCDMA
Series: AW / BW / NW / HW / PW
Application: Geological / Geotechnical / Core Drilling
Tube Type: Seamless Steel Tube
Thread: W-Series / DCDMA Connection
Length: Customized
Surface: Anti-Rust Protection
OEM: Available
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Description
DCDMA Standard Casing Tube for Geological and Geotechnical Drilling
AW, BW, NW, HW and PW casing tubes for geological exploration, geotechnical drilling and core drilling applications.
Our DCDMA Standard Casing Tubes are designed to stabilize borehole walls and protect drilling operations in loose, fractured or unstable formations. The casing is installed in the borehole to help prevent collapse, isolate unstable zones and provide a stable passage for subsequent core drilling tools. Available in common AW, BW, NW, HW and PW sizes, with precision-machined threaded connections and customized lengths according to drilling requirements.
Standard DCDMA | Series AW / BW / NW / HW / PW | Application Geological / Geotechnical / Core Drilling |
Tube Type Seamless Steel Tube | Thread W-Series / DCDMA Connection | Length Customized |
Stabilizing the borehole wall and protecting drilling operations
Casing is not simply a steel pipe. Its main functions include:
Stabilize the Borehole Wall Prevent collapse in loose formations. | Isolate Unstable Zones Isolate unstable or fractured zones from the drilling operation. | Protect the Upper Borehole Protect the upper section of the borehole during drilling. |
Provide a Stable Passage Provide a stable passage for drill rods and core barrels. | Support Fluid Circulation Support drilling-fluid circulation during core drilling. | Maintain Borehole Integrity Help maintain borehole integrity during drilling. |
The purpose of casing is to maintain borehole stability before or during core drilling — not to cut the formation. Casing must have sufficient bending, torsional and tensile capability for the drilling conditions.
Used across exploration, geotechnical and unstable formation drilling
DCDMA casing tubes are commonly used in geological exploration, mineral exploration, geotechnical investigation, diamond core drilling, PDC core drilling, engineering geological drilling, water well investigation, foundation investigation, unstable formation drilling and overburden drilling.
01 Geological & Mineral ExplorationCasing support for exploration drilling through overburden and unstable upper zones. | 02 Geotechnical & Foundation InvestigationBorehole stabilization for geotechnical investigation, foundation investigation and engineering geological drilling. |
03 Diamond & PDC Core DrillingUsed as part of core drilling systems that include diamond core bits, PDC core bits and wireline core barrels. | 04 Unstable & Overburden DrillingBorehole support in loose, collapsible and unconsolidated overburden conditions. |
Where casing support is required
Casing is especially useful in the following formation conditions:
Loose Soil | Sand and Gravel | Weathered Formations | Fractured Rock |
Collapsible Formations | Unconsolidated Overburden | Water-Bearing Loose Zones | Mixed Unstable Formations |
AW / BW / NW / HW / PW nominal dimensions
The following dimensions are nominal / reference dimensions. Final dimensions and tolerances should follow the confirmed casing specification and thread system.
| Size | Outside Diameter | Inside Diameter | Typical Wall Thickness |
|---|---|---|---|
| AW | 57.4 mm | 48.6 mm | approx. 4.4 mm |
| BW | 73.2–73.3 mm | 60.5–60.6 mm | approx. 6.35 mm |
| NW | 89.1 mm | 76.4 mm | approx. 6.35 mm |
| HW | 114.3 mm | 101.6 mm | approx. 6.35 mm |
| PW | 139.7 mm | 125.5–127 mm | approx. 6–7 mm |
Why AW / BW / NW / HW / PW?
The W-Series is a widely used casing system for core drilling and geotechnical applications. From smaller to larger nominal sizes: AW → BW → NW → HW → PW.
Larger Internal Clearance Larger casing sizes provide larger internal clearance for downhole tooling. | Compatibility with Larger Tooling Compatible with larger downhole tools and core drilling systems. | Casing Nesting Standard DCDMA W sizes can be used for casing nesting, an important design feature of the W-Series. |
Cold-drawn seamless steel tubing
High-quality casing tubes are commonly manufactured from cold-drawn seamless steel tubing. Benefits include:
Consistent Wall Thickness | No Longitudinal Weld Seam | Good Torsional Performance | Good Axial Load Capacity | Suitable for Threaded Joints |
Precision-machined casing threads and heat treatment
The casing connection is a critical part of the casing string. Accurate thread machining helps provide reliable connection between casing sections, stable torque transmission, better resistance to loosening, easier assembly and disassembly, and reduced risk of premature thread damage.
Thread W-Series Casing ThreadW-Series casing typically uses the corresponding standard thread structure. Straight thread and double-butt joint designs can be used to enhance connection strength under driving and jarring conditions. | Heat Treatment Heat-Treated OptionsHeat treatment can be applied to improve strength, toughness, thread wear resistance, fatigue resistance and connection durability. Heat treatment can be applied to the whole tube or to the ends, depending on specification. |
Cleaning and protection after machining
After machining, thread surfaces can be cleaned and treated to improve surface condition and corrosion resistance.
Deburring | Thread Cleaning | Anti-Rust Protection | Phosphate Treatment (if specified) | Thread Grease | Protective Caps |
Lengths supplied according to drilling requirements
Common configurations in the industry include 1.5 m, 3.0 m and customized lengths. Our casing is currently supplied primarily as a customized-length product.
1.5 m | 3.0 m | Customized Length |
A casing tube performs a different role from the drill rod
A casing tube is part of the complete drilling system, but it performs a different role from the drill rod.
Casing Tube Supports and stabilizes the borehole wall. | Drill Rod Transmits rotation, torque and drilling fluid. | Core Barrel Receives and protects the rock core. | Core Bit Cuts the formation and creates the core sample. |
Casing Tube → Drill Rod → Core Barrel → Reaming Shell → Core Bit
Part of a complete core drilling system
DCDMA casing tubes can be used as part of drilling systems that include:
PDC Core Bits | Impregnated Diamond Core Bits | Wireline Core Barrels | Drill Rods | Reaming Shells | Casing Shoes |
Casing shoes for the lower end of the casing string
The lower end of the casing is usually fitted with a casing shoe, which helps the casing enter the formation, ream the hole and protect the casing front end. Casing shoes are available in different sizes to match the corresponding casing series.
AW Casing Shoe | BW Casing Shoe | NW Casing Shoe | HW / HWT Casing Shoe | PW Casing Shoe |
Borehole stabilization with DCDMA W-Series compatibility
Seven design advantages behind the DCDMA Standard Casing Tube.
01 / 07 DCDMA W-Series CompatibilityAvailable in AW, BW, NW, HW and PW sizes. | 02 / 07 Seamless Steel ConstructionSuitable for demanding geological and geotechnical drilling applications. | 03 / 07 Precision ThreadingAccurate thread machining helps improve connection reliability. |
04 / 07 Borehole StabilizationDesigned to support loose, fractured and unstable formations. | 05 / 07 Heat-Treated OptionsAvailable according to casing specifications and project requirements. | 06 / 07 Custom LengthsLengths can be produced according to drilling requirements. |
07 / 07 Complete Core Drilling SystemCan be supplied with drill rods, casing shoes, core barrels and core bits. | Designed for reliable service in geological and geotechnical drilling applications when correctly selected and operated. | |
Customized according to confirmed technical requirements
We can customize the following according to confirmed technical requirements:
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How to select the correct casing tube
Please provide the following information for an accurate recommendation:
01 Casing Size AW / BW / NW / HW / PW. | 02 Required Length Required casing length. | 03 Borehole Diameter Borehole diameter and drilling system. |
04 Core Drilling System Matching core drilling system. | 05 Formation Condition & Thread Standard Formation condition and required thread standard. | 06 Casing Shoe Requirement & Drilling Depth Casing shoe requirement and planned drilling depth. |
Send us your existing casing dimensions, thread photos or core drilling system model, and we can help identify the correct casing specification.
Inspection focused on dimensions, threads and surface condition
For casing tubes, quality inspection should focus on the following:
Outside Diameter Inspection | Inside Diameter Inspection | Wall Thickness Inspection | Straightness Inspection |
Thread Dimension Inspection | Thread Fit Inspection | Surface Inspection | Final Packaging Inspection |
Professional drilling tools manufacturer in China
Chenghui Drilling supplies core drilling tools and customized drilling solutions for geological exploration, mineral exploration, geotechnical investigation and engineering drilling. Our core drilling range includes DCDMA Casing Tubes, AQ / BQ / NQ / HQ / PQ Drill Rods, Core Barrels, Diamond Core Bits, PDC Core Bits, Reaming Shells and Casing Shoes. Different casing sizes, lengths and connections can be matched according to the drilling system and project requirements.
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Need DCDMA Standard Casing Tubes?
Share your casing size, required length, borehole diameter and core drilling system with our engineers. If the exact specification is uncertain, send us your existing casing dimensions or thread photos, and our team can help identify the correct casing specification.
| 1. Casing Size (AW / BW / NW / HW / PW) | 2. Required Length |
| 3. Borehole Diameter & Core Drilling System | 4. Formation Condition & Thread Standard |
FAQ
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What is a DCDMA casing tube?
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What casing sizes are available?
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3
What is the difference between casing and drill rod?
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What lengths are available?
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Can casing tubes be supplied with casing shoes?
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Downloads
| File | Download |
|---|---|
| CNC-Machining-Center.pdf | Download |












