Specs such as horsepower, operating weight and dig depth/reach typically garner initial attention with an excavator. But the bucket at the end of the stick can also have a tremendous effect on how well a particular machine performs on a jobsite. And, since a bucket can last the lifetime of its host, it makes sense to pay attention to its selection.
Your customer's goal is to scoop up the maximum amount of whatever material they're moving. Accomplishing that usually requires creating a balance between capacity and application. Mount a bucket that's too large for the application and you might excavate more than is necessary or, worse yet, cause damage to the bucket or machine and/or compromise operator safety. Mount one that's too small and it will simply take too much time to dig.
There is a wide array of buckets available - everything from general-purpose, heavy-duty and severe-duty buckets to specialty buckets such as those for digging and moving rock, coral and lava. The differences between them center around abrasion resistance and wearability, as well as the ground engaging tools (GET) attached to the digging edge. They can also be spec'd in a variety of capacities and widths. In addition, specialty buckets are available with a variety of designs, shapes (i.e., V-shaped) and GET.
How tough does it need to be?
It's crucial to use the right bucket, since a misstep can reduce productivity and lead to premature wear.
"If you use a general-purpose bucket in rock, you can break it and cause failures, which create downtime and replacement costs," says Greg Cveykus, director of engineering, Kenco. "There aren't too many detrimental effects for using a heavy- or severe-duty bucket in light soils. But if you do the majority of your work with a heavy-duty bucket in a general-purpose environment, you have more equipment investment than needed."
A general-purpose bucket will typically be of higher capacity. Many are also smooth lipped. If they do have teeth, they are usually wider and closer together to provide added capacity.
"They are meant for black dirt conditions," notes Cliff Gabriel, regional sales representative, Werk-Brau.
General-purpose buckets are typically made of lighter-grade steel. Wear plates and guards can be added for increased durability, and wear straps, if used, will run with the same radius as the bucket.
Heavy- and severe-duty buckets are made of increasingly heavier grade steel, such as T-1 or AR400 or 500, to better withstand abrasive working conditions, including dense clay, sand and gravel, as well as rock, shot rock and stone.
These buckets do not need to be hardfaced; doing so can actually be detrimental. "Welding heats up the bucket and, as it cools, it shrinks and puts stress concentrations on the surface," says Lee Horton, president, Leading Edge Attachments. "These harder steels are more likely to crack under these conditions."
To endure the more severe working conditions, the buckets will have a thicker front lip with horizontal straps across the back and a thicker bottom or back plate. GET runs the gamut from wide teeth to rock-penetrating points.
"Over the last two years, we've seen a dramatic change from the general-purpose to the heavy-duty bucket to cover multiple applications," says Gabriel. "That's because a heavy-duty bucket is more versatile and can dig black dirt as well as rock."
To determine which type of bucket is best for your application, consider where you're digging. "Soil conditions across the United States are different," Gabriel says. "In Wisconsin, you may be able to use a general-purpose bucket with high capacity. But if you're digging in Miami, you will likely need a coral bucket - a severe-duty bucket with teeth close together so it can chip away at the ground."
Various soil types also have different weights. Those weights become important when you consider how the bucket will be used, i.e., digging over the side (which will reduce capacity) or front/back.