Measuring Wear on Bucket Base Edges (Determining Useful Life) {6101} Caterpillar

Excavator

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Wheel Loader

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Introduction

A portion of each base cutting edge has been designed as a structural part of the bucket. The basic dimensions of the structural piece are increased to provide material that can be worn away without risking damage to the bucket.

Measurements of a base edge can determine how much of the protective "wear material" remains. When that wear material is gone, the base edge should be replaced to avoid possible damage to the structural part of the bucket.

Procedure to Measure Wear on Bucket Base Edges

The following procedures describe how to measure a base edge.

1. Tilt the bucket back to allow easy access to the edge.
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   Illustration 1	g02854418
   Front View of Bucket Corner (A) Base edge (B) Bucket corner (C) Weld (D) Thickness of edge

2. Determine where the thickness measurements will be made.

   • Buckets with No Teeth: Measure near each end of the bucket just inside the corner welds. Refer to Illustration 1

   • Buckets with Teeth: On buckets with corner teeth, measure mid-way between the last two teeth at each end of the bucket. On buckets without a tooth in the corner, measure just inside the corner welds and midway between the last two teeth at each end of the bucket. Measure a total of four places. Refer to Illustration 1.
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   Illustration 2	g02854422
   End View of Bucket Cutting Edge (D) Thickness of edge (E) Dimension from center of rear weld

3. Mark the spot where each measurement will be made.

   Note: If the inside of the bucket overlaps the rear portion of the base edge, the following measurements should be made on the bottom of the base edge. Otherwise, measure on top.

   1. Determine dimension (E) from the base edge dimensions Table 1 or calculate dimension (E) by estimating the original edge width and multiplying by 0.6.

   2. At each of the locations determined in Step 2, measure dimension (E) from the center of the rear weld. When measuring on the bottom of the edge, measure dimension (E) from the rear corner of the edge. Refer to Illustration 2.

   3. Mark each of these points on the edge with chalk. If the edge is already worn beyond dimension (E) at any point, the edge is already worn out. The edge should be replaced as soon as possible to avoid breakage.

4. Using a caliper, measure the thickness of the edge at each marked point. The smallest of the measurement becomes dimension (D). Refer to Illustration 2.

Procedure to Calculate Percent of Usable Wear Material That Has Worn Away

The following procedures describe how to use these measurements to estimate when that edge should be replaced.

1. Divide dimension (D) by the original thickness of that edge. Refer to the base edge dimensions Table 1 for the original thickness of Cat base edges. Competitive loaders probably have edges of similar thickness. Measure the edge in an area of little wear (next to an adapter, for example) if in doubt about the original thickness.
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   Illustration 3	g02855257
   Wear Graph (F) Percent of Useable Wear Material Worn Away (G) Percent of Original Thickness Worn Away (H) Severe (J) Moderate (K) Light

2. Determine Percent Worn.

   1. Locate "Percent of Original Thickness Worn Away" (G) on the wear graph. Refer to Illustration 3

   2. Read up to the diagonal line that best describes the job conditions.

   3. Locate "Percent of Useable Wear Material Worn Away" (F) on the wear graph. Refer to Illustration 3.

3. The "Percent of Useable Wear Material Worn Away" (F) on the wear graph tells how much "wear material" has been worn off. This number is also the percent of "wear life" of the edge that has already been worn away.

4. Estimate when the edge should be replaced.

   1. Divide the age of the base edge in months, service meter units, etc by the percent worn from Step 2.

   2. This result is the approximate "age" of the base edge when 100 percent of the wear material has been worn away and should be replaced. Refer to (F) "Percent of Useable Wear Material Worn Away" on Illustration 3.