Here's my version from an earlier post. I'm posting this only to show my take on channel fork construction. So far they have held up to anything my little machine is capable of lifting without any problems.
http://www.tractorbynet.com/forums/customization/128844-quick-attach-pallet-forks.html
http://www.tractorbynet.com/forums/customization/128844-quick-attach-pallet-forks.html