Bugger me. I knew the Rawl bolts were burly, but I wasn't expecting that.
Mikl: they install a bit easier if you lightly squash the cone at the bottom by tapping it with a hammer. In its unsquashed state it's wider than the hole, hence the difficulty banging it in. The action of the bolt screwing down into it expands it out again, which - in theory - undercuts or at the very least grips the bottom of the hole. |