Using an earth auger without a screw bit would be like trying to use a broken drill bit to drill a hole into a piece of steel. There’s nothing that’s going to allow it to track straight. This not only significantly reduces equipment performance but also raises safety concerns for the operator. You can also look for augers & auger accessories online.
Making sure the auger has adequate teeth is another commonly ignored maintenance issue. The teeth, located at the bottom of the auger flighting, are primarily responsible for digging, whereas the flighting is designed to push the loosened dirt up out of the hole.
When the teeth are in good shape, the auger can aggressively and efficiently dig in most materials. But if the teeth are worn down or missing, the stress is then placed on the auger flighting to do the digging, which severely limits performance and creates another wear issue.
Long term, the flighting will begin to wear down and start to taper, eventually looking like an ice cream cone. Once this point is reached, the auger will fail to dig straight holes and will commonly get stuck in the ground.
One reason this problem exists is that many earth auger owners don’t know what to look for to determine when the screw bit or teeth are worn out. Therefore, some manufacturers have developed wear indicators that provide an obvious visual indication that these parts need replacement.