DTH Hammers

18-Inch DTH Hammer — HADK-185 (SD18)

18-Inch DTH Hammer — HADK-185 (SD18)

Engineered for the most extreme large-diameter drilling programs in the 18"–24" / 457–610 mm bit range. Heavy-duty SD18 shank, 717 lb / 325 kg hardened piston — the most powerful in the Drill King lineup — at 1,100 blows per minute.

Bit Range (457–610 mm)
18"–24"
Thread Connection
8⅝" API REG BOX
Hammer OD
16.30" / 415 mm
Hammer Weight
3,653 lbs / 1,657 kg
18 Inch DTH Hammer

HADK-185: Power Engineered for the Extremes of Large-Diameter Drilling

The HADK-185 is Drill King International’s ultra-class DTH hammer, engineered for the most extreme large-diameter drilling programs in the 18″–24″ / 457–610 mm bit range. Built on the heavy-duty SD18 shank standard, this single-model class delivers maximum impact energy at 1,100 blows per minute through a 717 lb / 325 kg hardened piston — the most powerful piston in the Drill King product lineup and purpose-built for formations that demand the highest energy per blow.

At 3,653 lbs / 1,657 kg and 16.30″ / 415 mm outer diameter, the HADK-185 operates in a class where drill string weight, compressor capacity, and rotary drive capability must all be matched to the hammer’s specifications. The 8⅝” API REG BOX top sub connection — a box-end configuration that distinguishes the HADK-185 from all smaller Drill King models — combined with a 12,000 lb·Ft make-up torque and 10,000 lb·Ft rotation torque rating reflects the extreme mechanical requirements of 18-inch class drilling assemblies.

Operating in a lower working pressure window (100–200 PSI / 7–14 Bar) than smaller-class hammers, the HADK-185 is optimized for compressor configurations typical of ultra-large-diameter programs. Premium alloy construction, a precision heat-treated hardened piston, and a dual-bearing design (upper and lower bearings) ensure sustained performance on the most demanding remote drilling sites worldwide.

Robust SD18 Shank Design

Heavy-duty shank engineered specifically for the extreme torque, weight, and impact demands of 18-inch class drilling assemblies.

Maximum Impact Energy

A 717 lb / 325 kg hardened piston — the heaviest in the Drill King lineup — delivers maximum energy per blow for penetration in the hardest, most competent rock formations.

Ultra-Large-Diameter Capability

18"–24" / 457–610 mm bit diameters — the widest bore range in the Drill King DTH series, covering ultra-large-diameter mining, geothermal, and civil drilling programs.

High-Frequency Performance

1,100 blows per minute of sustained high-energy impact across the full 18"–24" bit range.

Heavy-Duty Torque Ratings

12,000 lb·Ft / 16,272 N·m make-up torque and 10,000 lb·Ft / 13,560 N·m rotation torque for extreme mechanical demands.

8⅝" API REG BOX Connection

Box-end top sub connection — unique among Drill King models — matched to heavy-duty large-diameter drill string configurations used in 18-inch class programs.

Optimized Lower Pressure Range

100–200 PSI / 7–14 Bar operation, matched to compressor configurations and rotary drive capabilities typical of ultra-large-diameter programs.

Dual-Bearing Design

Dual upper bearings (×2, HPDK18520U) and dedicated lower bearing (HPDK18520L) for enhanced load distribution and extended bearing service life under extreme radial loads.

Ultra-Large-Diameter Mine Development & Shaft Drilling

The 717 lb hardened piston, 1,100 BPM frequency, and 18"–24" bit range suit the widest blast-hole diameters, raise bore pilot holes, shaft sinking support, and deep hard-rock open-cut programs.

Deep Geothermal & Large-Diameter Water Well Drilling

Penetration energy, dual-bearing durability, and matched air consumption for geothermal and deep municipal/industrial water wells requiring 18"–24" bore diameters.

Large-Scale Quarry & Hard Rock Production Drilling

Maximum energy per blow and sustained 1,100 BPM output for wide-bench quarry programs in granite, basalt, dolerite, and other high-strength aggregates.

Major Civil Infrastructure & Foundation Engineering

Large-diameter foundation piles, bridge caissons, tunnel portal bores, culverts, and deep anchor programs requiring 18"–24" hole diameters.

Technical Specifications

Specification Value
Piston Weight 717 lbs / 325 kg
Application Bit Range 18" – 24" / 457 – 610 mm
Working Pressure 100–200 PSI / 7–14 Bar
Outer Diameter 16.30" / 415 mm
Hammer Weight 3,653 lbs / 1,657 kg
Effective Length 78" / 1,981 mm
Rotation Speed 5–15 RPM
Frequency 1,100 BPM
Top Sub Connection 8⅝" API REG BOX
Make-Up Torque 12,000 lb·Ft / 16,272 N·m
Rotation Torque 10,000 lb·Ft / 13,560 N·m
Shank Connections SD18

Air Consumption

Pressure (PSI) Pressure (Bar) CFM M³/Min
100 7 1,640 46.40
150 10.50 2,340 66.20
200 14 3,160 89.50

Parts & Maintenance

No. Part Name Qty Part Number
1 Top Sub 1 HPDK18502
2 Washer – Top 1 HPDK18504
3 Top Sub O-Ring 1 HPDK18503
4 Check Valve 1 HPDK18507
5 C.V. Spring 1 HPDK18509
6 Spacer Ring 1 HPDK18505
7 Disc Spring Set 1 HPDK18506
8 Air Distributor 1 HPDK18510
9 Air Dist. O-Ring 1 HPDK18511
10 Cylinder 1 HPDK18512
11 Piston 1 HPDK18514
12 Wear Sleeve 1 HPDK18501
13 Upper Bearing 2 HPDK18520U
14 Snap Ring 1 HPDK18515
15 Bit Ret. Ring 1 HPDK18518
16 Bit Ret. Ring O-Ring 1 HPDK18519
17 Lower Bearing 1 HPDK18520L
18 Drive Sub Washer 1 HPDK18524
19 Drive Sub 1 HPDK18522
Choke Set 1 HPDK18508
Complete Hammer HADK-185

Ready to specify the HADK-185 for your ultra-large-diameter drilling program?

Contact Drill King International today — including compressor sizing guidance specific to 18-inch class programs.

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Construction

Built tough enough for the unpredictability of job sites, our equipment minimizes costly downtime and re-drills.

Exploration

Every hole counts, and our tools are built to keep penetration rates high even in unpredictable, mixed formations.

Mining

Engineered for open-pit and underground alike, our tools lower per-meter drilling costs without sacrificing performance.

Oil & Gas

Engineered for the rigors of well-site conditions, our hammers and bits extend service life while reducing per-foot drilling costs.

Quarrying

Less downtime, fewer bit changes, more material moved. That's the Drill King difference for quarry operators who can't afford to slow down.

Water Well & Geothermal

From residential wells to large-scale geothermal fields, our tools are trusted to get the job done right the first time