Possible Clues:

• Is perhaps 8 down near to a nut? (6)
• It tightens a nut in a cleaning machine
• Plumber's rubber ring
• Ring of metal fitted between two surfaces to improve grip
• One is next thing to a nut with a ring
• Machine that often has a "heavy-duty" setting
• Ring placed between two surfaces to prevent leakage, as in tap
• Seal to prevent leakage
• Leak-stopping ring
• It did be herself that was the next thing to a nut