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MSD supplies concentric casing systems with fixed ring-bit configurations, including confirmed DTH and top hammer specifications for overburden casing advancement.
MSD supplies standard concentric casing systems with fixed ring-bit configurations for overburden casing advancement. This pilot-bit and ring-bit structure is separate from ODEX eccentric systems and from casing systems that use sliding blocks or movable wings.
The confirmed tables contain 16 DTH specifications from R114/9-80 to R610/12.7-513 and five top hammer specifications from R76/7-39 to R140/10-97. Casing dimensions, listed bit and hole dimensions, recommended hammer or drifter, and weight vary by row, so the complete row should be checked before selection.
| Specification | Casing OD | Casing ID | Wall Thickness | Hole Bit Diameter | Hole Diameter | Max Conversion | Recommended Hammer/Drifter | Weight (kg) |
|---|---|---|---|---|---|---|---|---|
| R114/9-80 | 114 | 94 | 10 | 10 | 92 | 80 | COP34/DHD3.5/TH3.5 | 10 |
| R127/10-90 | 127 | 107 | 10 | 10 | 105 | 90 | COP34/DHD3.5/TH3.5 | 16 |
| R140/10-97 | 140 | 120 | 10 | 10 | 116 | 97 | COP44/DHD340(TH4)/SD4/QL40 | 21 |
| R146/10-110 | 146 | 126 | 10 | 10 | 124 | 110 | COP44/DHD340(TH4)/SD4/QL40 | 22 |
| R168/12.7-125 | 168 | 142.6 | 12.7 | 12.7 | 141 | 125 | COP54/DHD350(TH5)/SD5/QL50/M50 | 27 |
| R178/12.7-135 | 178 | 152.6 | 12.7 | 12.7 | 150 | 135 | COP54/DHD350(TH5)/SD5/QL50/M50 | 32.5 |
| R194/12.7-145 | 194 | 168 | 12.7 | 12.7 | 166 | 145 | COP64/DHD360(TH6)/SD6/QL60/M60 | 42.5 |
| R219/12.7-170 | 219 | 193.6 | 12.7 | 12.7 | 191 | 170 | COP64/DHD360(TH6)/SD6/QL60/M60 | 58 |
| R245/12.7-195 | 245 | 219.6 | 12.7 | 12.7 | 214 | 195 | COP84/DHD380(TH8)/SD8/QL80 | 78 |
| R254/12.7-203 | 254 | 228.6 | 12.7 | 12.7 | 224 | 203 | COP84/DHD380(TH8)/SD8/QL80 | 84.5 |
| R273/12.7-223 | 273 | 247.6 | 12.7 | 12.7 | 241 | 223 | COP84/DHD380(TH8)/SD8/QL80 | 100 |
| R325/12.7-276 | 325 | 299.6 | 12.7 | 12.7 | 292 | 276 | COP84/DHD380(TH8)/SD8/QL80 | 135 |
| R406/12.7-350 | 406 | 380.6 | 12.7 | 12.7 | 377 | 350 | DHD112/(TH12)QL120/SD12/NUMA120 | 280 |
| R508/17.4-416 | 508 | 482.6 | 12.7 | 12.7 | 478 | 416 | QL200/SD18/NUMA180/TH18 | 522 |
| R560/12.7-475 | 560 | 534.6 | 12.7 | 12.7 | 528 | 475 | QL200/SD18/NUMA180/TH18 | 620 |
| R610/12.7-513 | 610 | 584.6 | 12.7 | 12.7 | 558 | 513 | QL200/SD18/NUMA180/TH18 | 710 |
APPLICATIONS
CASE STUDIES
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Read MoreA concentric casing system is a casing advancement system in which the pilot bit and ring bit cut on the same centerline. This standard fixed ring-bit structure is also associated with symmetric or Symmetrix-type systems for overburden drilling.
This page covers the standard concentric product entity. It does not cover the eccentric ODEX mechanism, discrete sliding blocks, or movable wing cutters, which belong to separate MSD product pages.
The pilot bit drills the central section while the fixed ring bit opens the surrounding clearance required for the casing to advance. The cutting assembly remains concentric with the casing rather than using a swing-out eccentric reamer or a retractable block or wing mechanism.
The selected specification must be treated as a complete configuration. Casing dimensions, pilot and ring-bit dimensions, hammer or drifter, drill string, and the retrieval or continuation procedure should be checked together before use.
The DTH table contains 16 listed specifications from R114/9-80 to R610/12.7-513, with casing ODs from 114 to 610 mm. The listed recommended hammer options and weights change by specification.
The top hammer table contains five listed specifications from R76/7-39 to R140/10-97, with casing ODs from 76 to 140 mm. The listed drifter/thread options run from R32 to T45/T51 according to the specific row.
These figures describe the endpoints of the confirmed tables. They do not indicate that every intermediate size or an unlisted hammer or drifter combination is available.
First choose the applicable DTH or top hammer table. Then match the required casing OD and ID with the wall thickness, listed bit and hole dimensions, maximum conversion, recommended hammer or drifter, and weight in the same specification row.
A model designation or casing OD alone is not enough to confirm the assembly. Similar nominal sizes can have different listed dimensions, power-tool requirements, and weights, and information from one row should not be transferred to another row without confirmation.
Standard concentric ring-bit systems may be evaluated for water-well, construction, foundation, and other overburden drilling work where casing advancement is required. Product selection should be based on the actual ground profile, required casing dimensions, drilling method, equipment, hole direction, and required cased depth.
The confirmed tables establish dimensions, listed hammer or drifter options, and weights. They should not be used to infer universal formation limits, penetration rates, service life, maximum drilling depth, hole-straightness results, or project outcomes.
For a quotation, provide the required casing OD and ID, wall thickness, target hole dimensions, selected DTH or top hammer drilling method, exact hammer or drifter model, drill-rod or thread information, drilling rig details, casing length and connection, ground description, required cased depth, hole direction, and quantity.
For replacement orders, also provide the current specification, product markings, measured dimensions, and clear photos or drawings. MSD will compare the information with the confirmed table before recommending a listed configuration.
MSD is a China-based rock drilling tools manufacturer supplying casing systems and related drilling tools. MSD has 23 years of rock drilling tools manufacturing experience, exports to 40+ countries, and operates under ISO 9001 certified quality management.
MSD focuses on reliable quality, correct product selection, and technical support. For a concentric casing system enquiry, the team reviews the required casing dimensions, drilling method, hammer or drifter, equipment, and ground information before confirming the suitable listed configuration.
Technical content reviewed by MSD Engineering Team. | MSD — 23 years of rock drilling tools manufacturing expertise | ISO 9001 Certified | Exporting to 40+ countries
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