8 Inch DTH Hammers

8 Inch DTH Hammers Overview

MSD offers five 8 inch DTH hammer configurations that collectively cover Ø195–254 mm drilling: MSD8A, DHD380, QL80, M80, and SD8. The exact hole range depends on the selected model. DHD380, QL80, and SD8 cover Ø195–254 mm, MSD8A covers Ø198–254 mm, and M80 covers Ø195–245 mm.

All five models use an API 4 1/2" REG top sub thread, operate within a confirmed working pressure range of 1.5–3.3 MPa, and have a recommended rotation speed of 30–60 r/min. Their bit shanks, outer diameters, lengths, weights, hole ranges, and air consumption differ, so selection should be based on the complete drilling system rather than the 8 inch designation alone.

Choose the Model by Bit Shank

The bit shank is one of the main selection points because the DTH hammer and drill bit must use the corresponding connection configuration.

MSD8A DTH Hammer — Uses an MSD8A bit shank.

DHD380 DTH Hammer — Uses a DHD380 bit shank.

QL80 DTH Hammer — Uses a QL80 bit shank.

M80 DTH Hammer — Uses a MISSION80 bit shank.

SD8 DTH Hammer — Uses an SD8 bit shank.

A similar nominal hammer size does not automatically confirm compatibility. Start with the bit shank required by the selected drill bit or existing drilling system, then confirm the corresponding hammer model, top sub thread, drill-pipe connection, dimensions, and operating parameters.

Hole Range, Outer Diameter, and Shared Parameters

The five models collectively cover Ø195–254 mm drilling, but their exact hole ranges differ.

MSD8A DTH Hammer — Ø198–254 mm

DHD380 DTH Hammer — Ø195–254 mm

QL80 DTH Hammer — Ø195–254 mm

M80 DTH Hammer — Ø195–245 mm

SD8 DTH Hammer — Ø195–254 mm

The hammer body outer diameter also differs.

MSD8A DTH Hammer — Ø185 mm

DHD380, QL80, M80, and SD8 DTH Hammers — Ø180 mm

All five models share the following parameters.

Top Sub Thread — API 4 1/2" REG

Working Pressure — 1.5–3.3 MPa

Recommended Rotation Speed — 30–60 r/min

The API 4 1/2" REG top sub thread should be checked against the drill-pipe connection and any adapter used in the drill string. The model-specific length, weight, bit shank, hole range, outer diameter, and air consumption should be reviewed separately in the parameter table.

Air Consumption and Compressor Matching

Air consumption differs between the five models, even though they belong to the same nominal size class. Compressor selection should therefore use the exact values listed for the selected hammer.

MSD8A — 25 m³/min at 1.8 MPa and 34 m³/min at 2.4 MPa

DHD380 — 26 m³/min at 1.8 MPa and 34 m³/min at 2.4 MPa

QL80 — 26 m³/min at 1.8 MPa and 34 m³/min at 2.4 MPa

M80 — 26 m³/min at 1.8 MPa and 35 m³/min at 2.4 MPa

SD8 — 26 m³/min at 1.8 MPa and 34 m³/min at 2.4 MPa

The compressor should provide the required pressure and sufficient discharge capacity for the selected hammer's listed air consumption. Rated pressure and rated discharge capacity should be checked together, because pressure alone does not confirm that the available airflow is sufficient.

Air-consumption values should not be estimated from the 8 inch designation or extrapolated beyond the confirmed pressure points. Pressure losses in the hose, drill pipe, connections, and adapters should also be considered when reviewing the available air supply.

When to Choose an 8 Inch DTH Hammer

An 8 inch DTH hammer may be considered when the required hole diameter falls within the exact range of the selected model and the drilling equipment can support its connection and air requirements.

Target Hole Diameter — Confirm that the required diameter is within the model-specific range.

Bit Shank — Confirm that the drill bit uses the required bit shank.

Top Sub Thread — Check that the API 4 1/2" REG top sub thread matches the drill pipe or selected adapter.

Hammer Outer Diameter — Confirm that the hammer body diameter is suitable for the selected drilling arrangement.

Compressor Output — Confirm that the compressor can provide the required pressure and sufficient discharge capacity.

Rotation Speed — Confirm that the rig can operate within the recommended 30–60 r/min range.

Application and Formation — Confirm that the selected configuration suits the actual hole depth, formation, and operating conditions.

The M80 DTH hammer should not be treated as having the same maximum hole diameter as the other models because its confirmed range ends at Ø245 mm. The MSD8A also differs because its confirmed minimum hole diameter is Ø198 mm and its outer diameter is Ø185 mm.

The confirmed 6 inch range extends to Ø216 mm, while the 10–15 inch range begins at Ø254 mm. For projects near these boundaries, compare the exact hole range, bit shank, hammer body diameter, connection, compressor output, and operating parameters of the relevant models rather than relying on nominal size alone.

Common Application Directions

Within the collective Ø195–254 mm range, the five 8 inch DTH hammer models may support selected mining blast-hole, water-well, construction, foundation, and infrastructure drilling projects where the model-specific hole range and equipment requirements are satisfied.

The correct application depends on the selected model and the complete drilling arrangement. The required bit shank, hammer body diameter, drill-string connection, compressor output, hole depth, formation, and operating conditions should all be reviewed before the configuration is confirmed.

Why Choose MSD

MSD is a China-based manufacturer of rock drilling tools, supplying DTH hammers, DTH drill bits, drill pipes, casing systems, and related drilling products.

MSD supplies five 8 inch DTH hammer configurations covering MSD8A, DHD380, QL80, MISSION80, and SD8 bit-shank systems. These models do not share identical hole ranges, body diameters, dimensions, or air-consumption requirements. MSD therefore reviews the hammer, drill bit, drill string, rig, compressor, and required hole diameter as one system before confirming the configuration.

Customers can submit their equipment and project information for technical review before the order is finalized.

Information Required Before Ordering

To confirm the correct 8 inch DTH hammer configuration, provide the following information:

Hole Diameter — Required drilling diameter.

Hammer Model — Preferred hammer model, if already known.

Bit Shank — Required bit shank and current DTH bit model, if available.

Connections — Top sub thread, drill-pipe connection, and any adapter used in the drill string.

Drilling Equipment — Drill-rig model, compressor rated pressure, and compressor rated discharge capacity.

Working Conditions — Drilling application, rock formation, expected hole depth, and any current compatibility or operating problem.

MSD will use this information to check whether the selected hammer, drill bit, drill string, rig, and compressor arrangement matches the intended drilling conditions.

Technical content reviewed by MSD Engineering Team. | MSD — 23+ years of rock drilling tools manufacturing expertise | ISO 9001 Certified | Exporting to 40+ countries