Attachment answers / Sizing & fitment
How do I measure my excavator's pin diameter and stick width?
Short answer
Measure four things with the bucket off: pin outside diameter at an unworn section, dipper width across the outside of the stick, pin-to-pin centre distance, and link pin diameter. Take them in millimetres, and photograph the stick end with a tape in frame.
Last reviewed August 2026 · Quarrymark Attachments sales engineering desk
This takes about ten minutes and eliminates the most expensive mistake in attachment buying. Do it with the bucket removed, the machine on level ground, the boom lowered and the engine off.
The four measurements
Pin outside diameter. Use a caliper, not a tape. Measure at the head end of the pin or wherever it has not been rotating inside a bushing. A worn pin reads undersize and will send you a band too small.
Dipper (stick) width. The outside-to-outside width of the stick where it sits between the bucket ears. This sets the internal ear spacing the bucket needs. Measure at the very end of the stick, not further up - many sticks taper.
Pin-to-pin centre distance. Centre of the bucket pin to centre of the link pin, with the linkage in a neutral position. This one governs whether the bucket curls through its full arc without hitting the stick.
Link pin diameter. Frequently different from the bucket pin. Measure it separately rather than assuming.
Metric, and why
Record everything in millimetres. Excavator linkages are specified in metric by every manufacturer we build for, our catalog bands are metric, and converting a fractional-inch tape reading is where transcription errors creep in. If your tape is imperial, measure in inches and multiply by 25.4 - do not round to the nearest common metric size, because 1.75 in. is 44.45 mm and the difference between that and 45 mm matters at the bushing.
The photograph is not optional
Take one photograph of the stick end square on, with a tape measure laid across the pin bore, and one from the side showing the link and the H-link geometry. A photo lets us catch the things a set of four numbers cannot: a non-standard link arrangement, an existing coupler you had not mentioned, a stick that has been repaired, or a machine that turns out to be a different variant from the one on the decal.
Send the four numbers and the two photos with your machine's make, model and operating weight, and fitment stops being a guess.
Can I measure the pin without pulling the bucket?
You can measure the exposed end of the pin and the dipper width with the bucket on, and that is often enough to confirm a band. You cannot reliably get the pin-to-pin centre distance, and you cannot see how worn the bore is.
What if the pin is badly worn?
Measure it anyway and tell us. A pin worn more than about a millimetre under nominal is a maintenance item in its own right, and fitting a new bucket to a worn pin transfers that wear straight into the new bushings.
