I recently acquired a 4″ Burnerd 4 jaw independent chuck. Now I need to find a chuck key – it looks like it’s 3/16″ square. I’ve trawled the usual suppliers with no luck yet. If anyone has one, please PM me, thanks.
Yes, make it yourself but twice as long and put the cross handle in the middle so it has two ends – then you can use the other end in the future for another chuck, or perhaps insert a bit of hex key to fit the tool holder screws.