Attachments for a Caterpillar 420 Backhoe

Buckets from 8" up to 18" wide are rated for a Caterpillar 420 Backhoe. The widths we stock in this class are 8", 18". On a 7.21 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.

A Caterpillar 420 Backhoe in the 7.21 t class typically runs 45 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. 5 of the 7 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.

Yes. 2 of our hammers are rated for a machine this size. They run 1,018–1,356 joules of impact energy, which is the range a 7.21 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.

Yes. 1 coupler in our range is rated for a machine at 7.21 t. A coupler is the single best purchase on a 7.21 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 45 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.