A good rock auger is expensive, very expensive. So I try to buy components and then assemble it myself. Retail on this kind of auger usually runs about twelve to sixteen hundred dollars. Buying from the manufacturer but at an individual's price will run eight to nine hundred. Buying through a distributor components I can have one for five to seven hundred. These prices are all for an eight inch auger. Here's the auger complete.
I had an old Little Beaver eight inch auger. This is a close up of their step bit for rock. It's better than a shovel. And it works real well on asphalt. It's designed for a one man machine with his body weight as the maximum down pressure.
I bought the auger head and coupler from my supplier. I used the flites from the Little Beaver auger. And I had some two inch schedule eighty pipe. Here's the components. BTW I use two inch hex for coupling. I've found it works a lot better than the round ones with pins.
This auger is good for only one thing and one thing only, digging rock. It'll plug up in grass or roots. In clay it's like using a telephone pole for an auger. But in limestone and other soft stone it gets after it if one can put on some down pressure. I'll be using up to two thousand pounds down pressure and almost thirty gallons per minute hydraulic pressure. It's a lot better than a shovel.
I've put more than one auger on the way to a productive career digging holes by tossing the factory blade and gluing a grader blade piece in it's place. The first time I learned that one was 66 in Viet Nam. We were attempting to dig telephone pole holes in hard clay without any luck. An old timer, must have been in his middle twenties, welded a chunk of grader blade on for a cutting edge and we were in business like we'd never been before.