Ian White GM3SEK wrote in news:vjC1vRDSbWvGFAt1
@ifwtech.co.uk:

....
The only special part is the slotted shank that snaps into the chuck.
This is exactly the same on every SDS+ drill bit and tool, so you can
simply buy the cheapest item you can find (probably a small masonry
bit)
and chop off the end that you don't need.

Then find a short piece of steel tubing that will slide loosely over
the
end of your ground rods, and have the two parts welded together.

This can't be too hard, can it Ian!

I just looked on Ebay here in Oz, and I can buy a 20mm SDS chisel for
about $14 delivered. I would cut the shank just above the chisel end and
slip a 50mm long piece of 20mm NB steel pipe over the remaining shank
end, weld it on, and there you go. Ideally, the end of the tool should be
harder, but if you are only driving a few rods, you probably won't split
the collar.

Wrap your copper clad earth rod with a good few wraps of electrical tape
so that the tool does not noodle up the end of the electrode.

Protect your eyes when using this type of tool, especially improvising
tools from cheap asian chisels.

Owen