Attachments for a Caterpillar 309 CR
A Caterpillar 309 CR is a 21,600 lb (9.8 t) mini excavator, which puts it in the 6–10 t midi class. It takes 50 mm bucket pins on a pin-on stick. 13 attachments in the Quarrymark range fit a Caterpillar 309 CR: 3 digging buckets, 2 hydraulic hammers, 2 quick couplers, 2 severe duty buckets and 2 thumbs, plus 1 bucket and 1 grapple. 3 of those are a direct fit: right weight class, right pin diameter. Prices start at $1,243.20.
Caterpillar 309 CR
| Operating weight | 21,600 lb · 9.8 t |
|---|---|
| Weight class | 6–10 t · midi |
| Bucket pin diameter | 50 mm |
| Coupler / interface | Pin-on |
| Machine type | Mini Excavator |
| Attachments that fit | 13 (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.
13 attachments for a 309 CR
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 Caterpillar 309 CR
Digging Buckets for a 309 CR
3 digging buckets
Check pin size
Borderline
BorderlineHydraulic Hammers for a 309 CR
2 hydraulic hammers
Fits your class
BorderlineQuick Couplers for a 309 CR
2 quick couplers
Direct fit
Check pin sizeSevere Duty Buckets for a 309 CR
2 severe duty buckets
Check pin size
BorderlineThumbs for a 309 CR
2 thumbs
Buckets for a 309 CR
1 bucket
Buying attachments for a Caterpillar 309 CR
What size bucket fits a Caterpillar 309 CR?
Buckets from 8" up to 48" wide are rated for a Caterpillar 309 CR. The widths we stock in this class are 8", 18", 30", 36", 42", 48". On a 9.8 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 Caterpillar 309 CR use?
A Caterpillar 309 CR in the 9.8 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. 7 of the 13 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 Caterpillar 309 CR?
Yes. 2 of our hammers are rated for a machine this size. They run 1,356–2,712 joules of impact energy, which is the range a 9.8 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 Caterpillar 309 CR?
Yes. 2 couplers in our range are rated for a machine at 9.8 t. A coupler is the single best purchase on a 9.8 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 2 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.
