The impact cap slides into the female threaded end of all shafts (opposite the point or male threaded end). It is the part that receives the impact blows from the sledge hammer or jack hammer in order to drive the tool through the ground. After the shaft with the impact cap is driven in and another shaft needs to be connected then the impact cap is removed by pulling it out. If it is to tight to pull out by hand then it may be tapped with whatever object to loosten it. The next shaft is then threaded into the shaft where the impact cap was just removed, and the impact cap is re inserted into the female end of the newly connected shaft, and so on...
We purchased 8-9yrs ago the Bullet Mole set up, 60' of rods, plus all the parts in order to install up to 2" watermains in some of the hardest rock, tree roots and red clay in NWA.
We have driven these rods horizontally using an electric jackhammer through several hundred of feet, probably well into a couple of thousand I'm sure.
The BM finally met its match recently, we couldn't drive it under a driveway and got it stuck.
Upon saw cutting the concrete and exposing the below surface conditions, we found the impact head struck a 4' thick by 15' wide solid granite stone.
The rods were at least 30' under the concrete driveway and the first two rods deflected and were driven until they turned at a near 90° angle.
None of the rods remained bent upon removing them and none them snapped either...Amazing!
We did however break the Impact Cap, due to the extreme heat generated from the force of the hours of jackhammering the impacting cap.
We called BM and they sent us a replacement Impact Cap over night and didn't charge us the shipping fees.
I highly recommend this tool and the people who stand by this product are awesome!
Drain King Plmg