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Rugged mechanical drive digger with a 3″ solid kelly bar for dependable performance and maximum crowd force in a wide range of soil conditions.
HM-38 Mechanical Pressure Digger
When you need brute force in the most stubborn soil, the HM-38 is the heavyweight of Highway’s mechanical pressure digger lineup. Designed around a 3″ solid kelly bar and a massive mechanical drive, it delivers the raw, unfiltered power that utility crews trust when failure is not an option. This isn’t just a machine — it’s a workhorse built to keep drilling long after others tap out.
The HM-38’s simple, proven design means fewer points of failure, easy serviceability in the field, and performance you can count on year after year. With the highest crowd force in its class and torque to spin the largest augers, it doesn’t hesitate when the going gets tough.
What to know:
- 3″ Solid Kelly Bar
- 65,000 ft/lbs Torque
- 28,000 lbs Crowd Force
- 11,400 Lbs Max Retract Force
- Up to 72″ Auger Diameter
- Mounts to single rear axle or specialty carriers
HM-38 Mechanical Pressure Digger Options
Standard
| Feature | Specification |
|---|---|
| Engine | John Deere 134 HP (100 kW) diesel; other makes available |
| Max Rotary Torque | 65,000 ft/lbs (88,128 Nm) |
| Rotary RPM | 0–233 RPM, variable speed |
| Kelly Bar | 3” (76.2 mm) solid |
| Digging Depth | Up to 22’ (6.7 m) |
| Hole Diameter | Up to 72” (1.83 m) |
| Basic Unit Weight | 14,500 lbs (6,577 kg) |
| Kelly Bar Crowd Force | 28,000 lbs max |
| Retract Force | 11,400 lbs max |
| Turntable Base | 240 degrees |
| Mainframe Travel | 36” (914.4 mm) |
| Outriggers | Rear A-frame |
| Hydraulic Tool Circuit | Fixed location |
| Warranty | 5 years on final drive |
Optional equipment includes auger adapters/extensions, tool boxes, tunnel storage, work & safety lighting, outrigger pads, wheel chocks, front winches, capstan hoists, air compressors, generator & inverters, cab guards, and more.
Optional
| Optional Feature | Specification / Option |
|---|---|
| Extended Digging Depth | Up to 25′ (7.62 m) |
| Alternate Kelly Bar | 4.5″ internally sealed kelly bar (in place of 3″ solid) |
| Polesetter Package | Fixed or 6′ (1.83 m) telescoping |
| Service Winch | 12,000 lb (5,443 kg) capacity |
| Water Tank | 100‑gallon poly or steel (378.5 L) |
| Outriggers | Straight‑down rear or add front A‑frame (in lieu of rear only A‑frame) |
| Hydraulic Hose Reel | 50′ (15.24 m) hydraulic hose reel |
| Fuel Capacity | Optional 50‑gallon (189.3 L) tank |
| Outboard Leveling | 20° to 20′, 10° to 30′ (application‑dependent) |
| Augers & Tooling | Auger storage, adapters, extensions, specialty tooling |
| Tool Boxes & Storage | Tunnel storage and custom racks |
| Work & Safety Lighting | Work lights, beacons, safety strobes |
| Outrigger Pads & Wheel Chocks | Available |
| Front Winches & Capstan Hoists | Available |
| Air Compressors, Generators & Inverters | Available |
| Cab Guards | Available |