How to Selecting an Excavator Bucket Size

Most construction projects benefit from a bucket that will increase productivity by reducing the number of passes the tool needs to make. Select the biggest excavator bucket that won't compromise efficiency—except when you have a particular size requirement, like when digging a trench. Remember that the bucket you use on a 20-ton excavator would be far too big for an 8-ton excavator. A bucket that's too big will require the machine to do more work, and each cycle will take longer, reduce efficiency, or cause the excavator to topple over.

Excavator Bucket Size Chart

Generally, a range of bucket sizes will work for the excavator you have. Mini excavator bucket sizes can range from specialty 6-inch buckets to 36-inch buckets. Keep in mind that some sizes only apply to grading buckets, and you shouldn't use other types of buckets with those dimensions. To see what size of bucket is possible for the weight of your excavator, use this sizing chart:

  • Up to 0.75-ton machine: Bucket widths of 6 inches to 24 inches, or 30-inch grading buckets.
  • 1-ton to 1.9-ton machine: Bucket widths of 6 inches to 24 inches, or grading buckets 36 inches to 39 inches.
  • 2-ton to 3.5-ton machine:Bucket widths of 9 inches to 30 inches, or 48-inch grading buckets.
  • 4-ton machine: Bucket widths of 12 inches to 36 inches, or 60-inch grading buckets.
  • 5-ton to 6-ton machine: Bucket widths of 12 inches to 36 inches, or 60-inch grading buckets.
  • 7-ton to 8-ton machine: Bucket widths of 12 inches to 36 inches, or grading buckets from 60 inches to 72 inches.
  • 10-ton to 15-ton machine: Bucket widths of 18 inches to 48 inches, or 72-inch grading buckets.
  • 19-ton to 25-ton machine: Bucket widths of 18 inches to 60 inches, or 84-inch grading buckets.

How Is Excavator Bucket Capacity Calculated?

Each job's bucket capacity depends on the size of your bucket and the material you are handling. Bucket capacity combines the material fill factor and density, the hourly production requirement, and cycle time. You can calculate your bucket's capacity for a particular project in five steps:

  1. Find the material weight, expressed in pounds or tons per cubic yard. Refer to the Fill Factor Data Sheet provided by the bucket manufacturer to find the fill factor for that particular material. This figure, expressed as a decimal or percentage, specifies how full the bucket can be with this type of substance.
  2. Find the cycle time by timing a loading operation with a stopwatch. Start the timer when the bucket begins digging and stop when the bucket starts to dig a second time. Take 60 divided by the cycle time in minutes to determine cycles per hour.
  3. Take the hourly production requirement — set by the project manager — and divide it by the cycles per hour. This calculation gives you the amount in tons moved per pass, known as the per cycle payload.
  4. Take the per cycle payload divided by the material density to arrive at the nominal bucket capacity.
  5. Divide the nominal bucket capacity by the fill factor. This number tells you exactly how many cubic yards of material you will be able to lift with each cycle.

Post time: Aug-16-2021