Possible Clues:

• Hand tool
• What a wrench for society with Anne in public relations
• Tool for fastening nuts
• Tool box contains not a thing - nothing less
• It's quite a wrench to get over the gap with this, perhaps
• Unreasonable request from Newby
• Tool -- second one missing from saddlebag
• What a wrench to have to work with a nut!
• What a wrench such a bridge, perhaps, may be (7)
• Wrench for nuts