A construction digger is a tracked or wheeled machine with a boom, an arm, and a bucket that scoops soil and loads it into trucks. Most people on a job site call it a digger. Most manufacturers call it an excavator. Both words point to the same machine. Weight classes run from under one ton up to more than 100 tons, and the class you pick decides what work you can take on.
This guide covers what these machines do, how the sizes differ, what a used unit costs, and what to check before money changes hands.
What a Construction Digger Does
The core job is earthmoving. The bucket cuts into ground, lifts the material, and swings it to a pile or a truck bed. That single action covers a long list of tasks.
Common work includes:
- Foundation and basement digging
- Trenching for water lines, sewer lines, and fire mains
- Road embankment shaping and grading
- Demolition of small structures and concrete slabs
- Pond and drainage ditch cutting
- Loading rock in quarries
- Land clearing and stump removal
- Pipe laying with a lifting hook on the bucket linkage
The upper structure rotates 360 degrees on most models. That lets the operator dig on one side and dump on the other without moving the tracks. It saves fuel and saves time.
Digger and Excavator Mean the Same Machine
Buyers in the UK, Ireland, Australia, and parts of Africa say digger. Buyers in North America and most spec sheets say excavator. Search engines treat the terms as near synonyms.
One real difference exists between a digger and a backhoe loader. A backhoe has a loader bucket on the front and a digging arm on the back. Its rear arm swings about 180 degrees, not a full circle. A construction digger has one arm, full rotation, and more digging force at the same weight.
Three Weight Classes and What Each One Handles
Operating weight is the number that matters most. It sets digging force, lifting capacity, and the trailer you need.
| Class | Operating Weight | Typical Dig Depth | Typical Bucket | Best Use |
| Mini / Compact | 0.8 – 10 t | 2.0 – 4.2 m | 0.02 – 0.35 m³ | Yards, drains, indoor demolition |
| Standard / Medium | 10 – 30 t | 4.5 – 7.0 m | 0.4 – 1.4 m³ | Foundations, roads, utilities |
| Large / Heavy | 30 t and above | 6.5 – 9.0 m | 1.5 – 3.0 m³ | Mining, quarry, heavy demolition |
Mini and Compact Diggers Under 10 Tons
Mini machines grew popular because cities got tighter. A 1.7-ton unit fits through a garden gate. Some micro models have retractable tracks that shrink below one meter wide, then widen again for stability.
Zero tail swing is the feature to look for. The counterweight stays inside the track width during rotation, so the machine works next to a wall without hitting it. A used mini excavator in the 3 to 6 ton range handles French drains, pump pits, fence lines, landscaping, and small footings.
Fuel burn sits around 3 to 6 liters per hour. One pickup truck and a tag trailer can move most units under 4 tons.
Standard Diggers From 10 to 30 Tons
This class does the bulk of construction work worldwide. The 20-ton group includes the Caterpillar 320, Komatsu PC200, Hitachi ZX200, Volvo EC210, and Hyundai 215. These models share similar reach, similar bucket size, and similar transport needs.
A 20-ton digger reaches about 6.5 meters deep. Bucket capacity sits near 0.9 m³. That is enough for house foundations, main water lines, and highway shoulder work.
Boom choice matters here. A standard mono boom gives the most breakout force. A two-piece articulating boom folds tighter and suits narrow urban streets. Long-reach booms trade force for distance and fit canal and slope work.
Large Diggers Above 30 Tons
Machines from 30 tons up move the highest volume per hour. A CAT 330, Komatsu PC350, Hitachi ZX350, or Sany SY365 falls in this group. Bucket sizes run 1.5 m³ and higher.
These units serve mining and quarry operations, river dredging, scrap handling, and structural demolition. High-flow auxiliary hydraulics let them run rock breakers and shears.
Transport gets complicated above 35 tons. Counterweights often come off. Sometimes the boom ships separately. Check local road limits before you buy.
Attachments That Change the Job
The bucket is only the starting point. A quick coupler lets one machine do several jobs in a day.
- Digging bucket — general soil and clay
- Ditching bucket — wide, flat, no teeth, for grading and cleanup
- Rock bucket — reinforced shell with heavy teeth
- Hydraulic breaker — concrete and hard rock
- Grapple — logs, scrap, and demolition debris
- Auger — fence posts and tree planting
- Compaction plate — trench backfill
- Thumb — holds material against the bucket for sorting
Match attachment weight and hydraulic flow to the machine. An oversized breaker on a small carrier cracks booms and burns pumps.
What a Used Construction Digger Costs
Prices depend on weight, hours, year, and brand. These figures reflect current export market values for machines in working condition.
| Machine Size | Hours | Typical Price Range |
| 1 – 3 t mini | 1,000 – 2,000 | 16,000 |
| 5 – 8 t compact | 800 – 2,300 | 24,000 |
| 12 – 15 t | 1,500 – 3,000 | 32,000 |
| 20 – 22 t | 1,000 – 3,000 | 50,000 |
| 30 – 36 t | 1,500 – 2,500 | 95,000 |
| 45 t and up | 1,000 – 2,800 | 105,000 |
Buyers working with a tight budget often start with machines priced under $20,000, which covers most mini and compact units with moderate hours.
A machine with 1,500 hours and a 2020 build date holds value far better than a 2018 unit with 3,000 hours. Service records raise the price and lower your risk.
Brands Buyers Ask About Most
Komatsu — strong hydraulics, simple electronics, parts available almost everywhere. The PC200 and PC300 series stay in demand across Africa, Latin America, and Southeast Asia. Browse full specs on the Komatsu excavator range.
Caterpillar — highest resale value, largest dealer network, higher purchase price. The 320 and 336 are the volume sellers.
Hitachi — smooth hydraulic control and good fuel numbers. The ZX200 and ZX350 are widely traded.
Volvo — comfortable cabs and efficient engines. EC210 and EC290 are common in the used market.
Doosan and Hyundai — Korean machines that cost less than Japanese equivalents with acceptable durability.
Sany and XCMG — Chinese brands with low entry prices and improving quality. Best value in the 20 to 35 ton range.
Kubota — the reference brand for mini machines under 6 tons.
Inspection Points Before You Pay
Check these items in order. Each one costs real money to fix.
- Undercarriage — measure track link pin wear, idler wear, and sprocket tooth shape. A full undercarriage rebuild on a 20-ton machine runs 15,000.
- Hydraulic cylinders — look for oil film on the rods. Scored chrome means a reseal or a new rod.
- Pin and bushing play — rock the bucket sideways. Movement over 3 mm at the pins signals wear.
- Engine start — a cold start tells you more than a warm one. Watch exhaust color for the first 30 seconds.
- Boom and stick welds — hunt for repair seams and paint that does not match.
- Slew bearing — swing the house and listen for knocking.
- Hour meter and ECU data — compare the meter to seat wear, pedal wear, and pin condition.
Also confirm the transport dimensions against your trailer and your local road rules. A machine you cannot move is a machine you cannot use.
Quick Answers
How much does a construction digger weigh?
Mini units weigh 0.8 to 10 tons. Standard units weigh 10 to 30 tons. Large units start at 30 tons and run past 100 tons in mining.
How deep can a digger dig?
A 3-ton mini reaches about 3 meters. A 20-ton machine reaches about 6.5 meters. A 45-ton machine reaches roughly 7.8 meters with a standard stick.
How many hours does a digger last?
Well-maintained machines run 10,000 to 15,000 hours before major rebuild. Some hit 20,000 hours with careful service.
What licence do I need?
Requirements vary by country. Most regions ask for a plant operator card or certificate rather than a road licence, since tracked machines rarely travel public roads.
Shanghai Yonggong Trading Co., Ltd has exported used excavators for over 20 years, holds ISO9001-2000 and 3C certification, and supplies inspected machines across all weight classes.
