Excavator Auger Attachments

What This Excavator Auger Attachment Collection Covers

Six Star Industries products sit in this collection, from $289 to $1,739. One of them is the drive — the Auger Complete Assembly — and the rest are what goes on it or around it: a T-post auger bit, a rock auger bit, a single flight heavy duty auger bit, fixed length shaft extensions, and auger racks. Buyers new to auger attachments often price the drive and stop there. In practice the bits are consumables that get replaced on their own schedule, and the extensions decide whether you can finish a hole at all.

Matching an Auger Drive to Your Machine

The drive has to match two things on your carrier: hydraulic supply and mounting. The Star Industries Auger Complete Assembly covers a hydraulic flow range of 5 to 35 GPM depending on the drive unit selected, with a maximum pressure of 3500 PSI, and turns augers up to 36 inches in diameter. Frames are offered for skid steer, mini skid steer, telehandler and backhoe carriers (SS, MSS, FL and BH frames).

Two rules follow from that table. First, undersizing flow does not just slow the auger down — it loads the drive at the wrong point in its curve and makes it stall in ground it should handle. Second, mounting is not universal. A skid steer drive hangs from a flat plate; an excavator or backhoe setup is pinned or bracketed to the stick or quick coupler. The frames listed above are what these assemblies are built for, so if you are fitting an excavator, confirm the frame and coupler with us before you order rather than assuming a plate will adapt.

Auger Bits: Ground Conditions Decide, Not Diameter

Diameter is the easy question. The harder one is what the bit has to cut through, and that is what separates the three bits here.

The single flight design clears spoil well in soil that comes up in a ribbon, which is why it also handles frozen ground and fractured rock without packing. A rock bit is a different tool: carbide bullet teeth chip rather than cut, and the reinforced head exists because the shock loads in rock are what break ordinary boring heads. Running a dirt-configured auger into rock rounds the teeth quickly and can twist a shaft, so buy for the worst ground on the job, not the average. The T-post bit is purpose-built for fence work — it drills a small, clean pilot hole rather than a footing.

Note that the rock auger bits are precision machined to fit a specific skid steer model and auger drive. That is a fitment question to settle at order time, not after delivery.

Reaching Depth With Shaft Extensions

Bit length sets your maximum hole depth, and extensions add to it. The fixed length shaft extensions here use a 2 inch hex coupler and heavy-duty steel construction, in 24, 36, 48, 60 and 72 inch lengths (models EXT-24 through EXT-72). Two practical points: the hex size on the extension has to match both your drive output and the bit, and every inch of extension raises the drive higher above grade at the start of the hole. That costs you boom reach, sight lines to the collar of the hole, and stability — a long extension on a small carrier is the usual reason a hole ends up out of plumb.

Storage and Wear Parts

Auger racks (models 160A-16, 160A-16-42, 160A-18, 160A-18-42) hold up to 10 augers, or 8 on single-sided models, on a reinforced steel frame at 42 or 48 inches tall depending on model. They support 16 and 18 inch diameter earth augers and a maximum auger diameter of 28 inches, and the -42 models add an extended compartment for auger extensions up to 42 inches. Worth reading closely: the bits in this collection go to 36 inches, while the racks top out at 28 inches, so the largest augers need their own storage. Teeth on both the single flight and rock bits are replaceable, and keeping a set of spares on the truck is cheaper than losing a day to a rounded-off bit.

Site Requirements and Operator Practice

An augered hole is an excavation. Before drilling on a construction site, OSHA 1926.651(b) requires that the estimated location of utility installations be determined before excavation begins, and the national 811 one-call system is how most contractors do that. Beyond locates, the failure modes with augers are consistent: nobody should be near a turning flight, spoil should be cleared with a shovel and not a boot, and a bit that binds should be backed out under power rather than pulled with the boom. Check pins, hex couplers and tooth retainers before each shift, and follow the manufacturer's manual for hydraulic hookup and torque values. Clay that balls up on the flight and frozen crust are the two conditions that most often get blamed on the attachment when the real answer is a different bit or a slower approach.