Here is what im talking about.
This is a cloe up of the bit screw thing itself, and the grabbernut that fits on it. Notice the raised corners. when you hammer it in, it really grabs in there well. Better than anything ive ever used.
How do I make the links clickable again?
There is also a bigger set here: http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=10416&group_ID=1254&store=snapon-store&dir=catalog
If anyone can find these anywhere other than Snap -on, I would be gratefull.