Attachments for a Komatsu PC78US-11
A Komatsu PC78US-11 is a 17,416 lb (7.9 t) mini excavator, which puts it in the 6–10 t midi class. It takes 50 mm bucket pins on a pin-on stick. 8 attachments in the Quarrymark range fit a Komatsu PC78US-11: 2 quick couplers, 1 bucket, 1 digging bucket, 1 grapple and 1 hydraulic hammer, plus 1 severe duty bucket and 1 thumb. 3 of those are a direct fit: right weight class, right pin diameter. Prices start at $1,243.20.
Komatsu PC78US-11
| Operating weight | 17,416 lb · 7.9 t |
|---|---|
| Weight class | 6–10 t · midi |
| Bucket pin diameter | 50 mm |
| Coupler / interface | Pin-on |
| Machine type | Mini Excavator |
| Attachments that fit | 8 (3 direct fit) |
Operating weight is from the manufacturer’s published spec sheet. Pin diameter and coupler style are derived from that weight against our own tonnage bands. They are the right starting point for a machine in this class, not a statement about your specific unit. Verify both against your OEM spec, or send us a photo of the stick end and we will confirm it before you order.
8 attachments for a PC78US-11
We grade the fit rather than answer yes or no. Direct fit means the weight class and the mounting both check out. Fits your class means the attachment is rated for a machine of this weight and mounts pin-on. Verify first means something, usually the pin diameter, needs confirming before it ships. Telling a contractor a bucket fits when it does not is how you earn a freight claim.
Everything that fits a Komatsu PC78US-11
Quick Couplers for a PC78US-11
2 quick couplers
Direct fit
BorderlineBuckets for a PC78US-11
1 bucket
Digging Buckets for a PC78US-11
1 digging bucket
Grapples for a PC78US-11
1 grapple
Hydraulic Hammers for a PC78US-11
1 hydraulic hammer
Severe Duty Buckets for a PC78US-11
1 severe duty bucket
Buying attachments for a Komatsu PC78US-11
What size bucket fits a Komatsu PC78US-11?
Buckets from 8" up to 36" wide are rated for a Komatsu PC78US-11. The widths we stock in this class are 8", 18", 36". On a 7.9 t machine the narrow end of that range is the trenching and utility-line width, and the widest sizes are for grading and cleanup, where you are moving loose material rather than breaking ground. Go wider than the machine's rated capacity and you will feel it as lost breakout force and a tippy load at full reach, not as a fitment problem.
What pin size does a Komatsu PC78US-11 use?
A Komatsu PC78US-11 in the 7.9 t class typically runs 50 mm bucket pins on a pin-on connection. That is the number to check first, because it is the one that stops a bucket going on: the weight class tells you whether the machine can lift the attachment, the pin diameter tells you whether it will physically pin up. 3 of the 8 attachments listed here are the right weight class but drilled for a different pin. They are flagged "check pin size", and a bushing kit or a quick coupler resolves them. Pin diameter is derived from the machine's operating weight against our own tonnage bands, so measure yours or send us a photo of the stick end before ordering.
Can I run a hydraulic hammer on a Komatsu PC78US-11?
Yes. 1 of our hammers are rated for a machine this size. They run 1,356 joules of impact energy, which is the range a 7.9 t carrier can actually feed. The constraint is hydraulic, not structural: the machine needs an auxiliary circuit with the flow and relief pressure the hammer is specified for, and a machine plumbed only for a thumb will not run a breaker without the second circuit. Check your auxiliary flow on the machine's spec plate, or send it to us and we will match the hammer to it.
Will a quick coupler fit a Komatsu PC78US-11?
Yes. 2 couplers in our range are rated for a machine at 7.9 t. A coupler is the single best purchase on a 7.9 t machine that changes attachments more than once a day: it turns a twenty-minute pin-and-hammer job into a thirty-second swap from the seat, and it decouples you from the 50 mm pin diameter so you can buy attachments on price and spec instead of on drilling. Worth pairing with one of the 1 thumbs that fit this machine. A coupler and a hydraulic thumb together is the combination most contractors in this class end up running. Free freight applies over $750.
