For maximum productivity, match the type and capacity to the job.
Buckets serve as the business end of your wheel loader or excavator. Choosing the right one can make the difference between good and poor performance.
With the optimal bucket choice, production increases without causing additional wear and tear on the equipment. It comes down to size and type. A bucket that’s too big increases load time and dump time while causing the machine to generate extra heat. Using the wrong type of bucket increases the cycle time for your excavator and the bucket fill time for your wheel loader.
Here’s what you need to know.
Excavator bucket size
To determine the maximum bucket size for your excavator, use the OEM specifications along with several calculations. OEM specs include the maximum lift capacity, bucket weight and bucket capacity. In addition, manufacturers often provide a chart that lists the material densities for soil, rock, gravel, clay and other materials.
Calculating the lift ratio will tell you whether the capacity of your excavator bucket will work for your job. To calculate the lift ratio:
- Start with the maximum lift capacity at full reach over the side.
- Add the weight of the OEM-provided bucket. The result is the adjusted lift capacity. Save that number for later.
- Calculate the attachment weight by adding up the weights of the bucket, coupler, thumb and any other attachments.
- Calculate the lift weight by multiplying the bucket capacity by the material density plus the attachment weight.
- Divide the lift weight by the adjusted lift capacity to get the lift ratio. A lift ratio of less than 1.0 indicates that the bucket capacity matches your application. A higher lift ratio means you’ll want a smaller-capacity bucket.
Wheel loader bucket capacity
To determine the optimal bucket size for your wheel loader, start by looking at the OEM specifications for the static articulated tipping load and the payroll, along with material density charts. The static articulated tipping load represents the amount of load that causes the loader to begin to tip over the front axle with a fully articulated, horizontally positioned boom.
According to ISO standards, the payload carried by the loader must not exceed 50 percent of the static articulated tipping load. You can determine the bucket capacity (in cubic yards) for your loader by dividing the allowable payload (in pounds) by the specific bulk weight (in pounds per cubic yard) of the heaviest loads you plan to handle.
Breakout force and bucket types
Breakout force indicates the amount of force a bucket can exert against material and the amount of force exerted by the machine during a “roll back” operation.
Choosing a bucket that lacks the necessary breakout force for the job — for example, a general purpose bucket instead of a rock bucket to excavate hard-packed rock — shortens the life of the machine, reduces performance and increases fuel and maintenance costs. Pushing the general purpose bucket to a higher breakout force places more stress on the cylinders, hydraulic system and the linkage that tilts the bucket.
General purpose vs. multipurpose
When you work with loose dirt, loam, mixed gravel and different soil types, general purpose buckets provide the best solution for digging, loading and clean-up. A multipurpose bucket, on the other hand, allows you to use your loader for not only loading, carrying and dumping materials but also grabbing different-shaped objects, dozing and leveling or spreading soil.
Light material, heavy duty and rock
You can use a light material handling bucket to move snow, compost and other materials that weigh less than 2,000 lbs./cubic yard with your wheel loader. These buckets include a spill guard that prevents materials from spilling over the linkage.
Excavating abrasive materials such as sand and crushed rock will be easier with a heavy-duty dig or high abrasion bucket. These buckets resist abrasion and withstand high breakout and impact forces.
You can use a rock bucket for excavating broken slag, sandstone, iron ore and high quartz granite or face loading tightly compacted materials. Rock buckets may include a spade nose or a straight edge and can accept different types of teeth.
If you need to use a medium or large excavator for grading or landscaping, a tilting bucket fits the bill. You can tilt the bucket up to 45 degrees in either direction.
You can use a ditching or trenching bucket to dig or clean out a ditch or for slope work during landscaping.
Manufacturers also offer special application buckets. These include skeleton buckets that separate rock from sand, buckets with clamps used to keep materials in the bucket and high dump buckets that can dump materials from a higher level than standard buckets.
John Ross has written about industrial, automotive and consumer technologies for 17 years.