5 Inch DTH Hammers

5 Inch DTH Hammers Overview

MSD offers five 5 inch DTH hammer configurations that collectively cover Ø135–155 mm drilling: MSD5A, DHD350, QL50, M50, and SD5. The exact minimum hole diameter depends on the selected model. The DHD350, QL50, and SD5 models cover Ø135–155 mm holes, while the MSD5A and M50 models cover Ø136–155 mm holes.

All five models use an API 2 3/8" REG top sub thread, a working pressure range of 1.0–2.5 MPa, and a recommended rotation speed of 30–60 r/min. Their bit shanks, outer diameters, lengths, weights, hole ranges, and air consumption differ. The hammer model, bit shank, top sub thread, compressor pressure, and compressor discharge capacity should therefore be checked before ordering.

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.

MSD5A DTH Hammer — Uses an MSD5A bit shank.

DHD350 DTH Hammer — Uses a DHD350 bit shank.

QL50 DTH Hammer — Uses a QL50 bit shank.

M50 DTH Hammer — Uses a MISSION50 bit shank.

SD5 DTH Hammer — Uses an SD5 bit shank.

A similar nominal hammer size does not automatically confirm compatibility. Final matching should be based on the selected drill bit or existing drilling system, the corresponding hammer model, the bit shank, the top sub thread, and the confirmed dimensions and operating parameters.

Hole Range, Outer Diameter, and Shared Parameters

The five models collectively cover Ø135–155 mm drilling, but their exact hole ranges differ.

MSD5A DTH Hammer — Ø136–155 mm

DHD350 DTH Hammer — Ø135–155 mm

QL50 DTH Hammer — Ø135–155 mm

M50 DTH Hammer — Ø136–155 mm

SD5 DTH Hammer — Ø135–155 mm

The outer diameter also differs by model.

Ø126 mm Outer Diameter — MSD5A, QL50, and M50

Ø125 mm Outer Diameter — DHD350 and SD5

All five models share the following operating parameters.

Top Sub Thread — API 2 3/8" REG

Working Pressure — 1.0–2.5 MPa

Recommended Rotation Speed — 30–60 r/min

The API 2 3/8" REG top sub thread should be checked against the drill-pipe connection and any adapter used in the drill string. Model-specific length, weight, bit shank, hole range, outer diameter, and air consumption should be checked separately in the parameter table.

Air Consumption and Compressor Matching

Air consumption differs between the five models and changes with operating pressure. Compressor selection should therefore use the exact values listed for the selected hammer.

MSD5A — 7 m³/min at 1.0 MPa and 13 m³/min at 1.5 MPa

DHD350 — 9 m³/min at 1.0 MPa and 15 m³/min at 1.8 MPa

QL50 — 9 m³/min at 1.0 MPa and 15 m³/min at 1.8 MPa

M50 — 7 m³/min at 1.0 MPa and 13 m³/min at 1.8 MPa

SD5 — 9 m³/min at 1.8 MPa and 15 m³/min at 2.4 MPa

The compressor should provide sufficient pressure and discharge capacity at the intended operating point. Its rated pressure and rated discharge capacity should be checked together because sufficient pressure alone does not confirm that the available airflow meets the selected hammer's requirement.

Air-consumption values should not be estimated from nominal hammer size or extrapolated beyond the listed pressure points. Pressure losses in the hose, drill pipe, and connection arrangement should also be considered when reviewing the available air supply.

When to Choose a 5 Inch DTH Hammer

A 5 inch DTH hammer may be considered when the required hole diameter falls within the selected model's confirmed Ø135–155 mm or Ø136–155 mm range.

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 2 3/8" REG top sub thread matches the drill pipe or selected adapter.

Compressor Output — Confirm that the compressor can provide the required pressure and sufficient discharge capacity for the selected hammer's listed air consumption.

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

Application and Formation — Confirm that the hammer configuration suits the actual formation and drilling conditions.

The confirmed 4 inch range ends at Ø135 mm, while three 5 inch models begin at Ø135 mm and two begin at Ø136 mm. For a project near this overlap, nominal hammer size alone should not determine the selection. The bit shank, hammer outer diameter, available compressor output, drill-string configuration, and required hole diameter should be compared.

The specific boundary between 5 inch and 6 inch hammers should be based on the final confirmed 6 inch parameter table rather than an industry sizing formula.

Common Application Directions

The Ø135–155 mm and Ø136–155 mm ranges may suit selected mining blast-hole, quarry, water-well, construction, and foundation drilling projects where this hole size is required.

Model selection should still be based on the required bit shank, available compressor output, drill-string connection, hole depth, formation conditions, and the exact parameters of the selected hammer.

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 5 inch DTH hammer configurations covering MSD5A, DHD350, QL50, MISSION50, and SD5 bit-shank systems. Because the models differ in body diameter, hole range, dimensions, and air consumption, MSD reviews the complete hammer, drill bit, drill string, rig, and compressor arrangement 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 5 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 the appropriate model and determine whether the hammer, drill bit, drill string, rig, and compressor configuration match 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