Excavator bucket pins are often identified using two basic measurements: diameter and overall length. A product described as a 100 mm x 750 mm bucket pin normally measures approximately 100 millimeters across and 750 millimeters from end to end.
Those two measurements are important, but they do not always provide enough information to confirm fitment. Pin shoulders, working length, grease passages, keeper locations, and retaining styles must also match the original component.
What Does a Bucket Pin Size Mean?
A size written as:
100 mm x 750 mm
usually means:
- Diameter: 100 mm
- Overall length: 750 mm
Some listings may reverse the order or use inches instead of millimeters. Always check the product specifications before assuming which measurement comes first.
Common Excavator Pin Measurements
The most important measurements include:
- Outside diameter
- Overall length
- Usable or working length
- Shoulder diameter
- Shoulder length
- Head or flange thickness
- Retaining-hole diameter
- Distance from the pin end to the retaining hole
- Grease-hole location
Why Diameter and Length May Not Be Enough
Two excavator pins can both measure 100 mm x 750 mm but still be incompatible. Differences may include:
- One pin has a retaining bolt hole while the other uses a keeper plate
- One pin includes a large head or flange
- The grease passages are in different locations
- The usable length between shoulders is different
- The pin ends use different threads or grooves
- The surface hardness or heat treatment is different
The replacement pin must match the machine’s entire joint design, not only the two primary dimensions.
Bucket Pin Locations
Excavators use pins at several points, including:
- Bucket-to-stick connection
- Bucket-to-link connection
- Linkage pivots
- Boom-to-stick connection
- Hydraulic cylinder connections
- Quick-coupler connections
Each position may use a different pin. Record the exact installation location before searching for a replacement.
Measure the Original Pin Carefully
Use a caliper or micrometer to measure diameter. Use a steel tape, ruler, or caliper to measure length. Clean grease, rust, and dirt from the pin before measuring.
If the old pin is worn, measure several areas and use the least-worn section as the best indication of the original diameter.
Check the Bushing Inside Diameter
The pin diameter and bushing inside diameter must work together with the manufacturer’s intended clearance. A pin should not be selected simply because it can be forced through the bore.
Excessive clearance can cause:
- Bucket movement
- Clunking
- Uneven loading
- Accelerated pin wear
- Accelerated bushing wear
Verify Brand, Model and Serial Number
Machine brands such as CAT, Caterpillar, John Deere, Komatsu, Hitachi, Volvo, Case, Kobelco, and others may use several pin configurations within the same general model series.
Always confirm:
- Machine manufacturer
- Exact model
- Serial-number range
- Attachment type
- Pin location
- Original part number
When a Universal-Size Pin May Be Appropriate
A dimension-based replacement may be appropriate when the original pin measurements, retaining style, working length, grease configuration, and material requirements all match.
Do not treat a pin as universal based solely on diameter and length.
Find the Correct Replacement Pin
Northline Parts carries aftermarket excavator bucket pins listed by physical size and selected equipment applications. Compare the complete specifications with the original pin before ordering.
For a 100 mm x 750 mm replacement, verify that both measurements, the usable length, retaining system, grease passages, and machine application are compatible.