Cover Hook (End Hook)

The cover hook is also known as End Hook. It is formed from the curling of the lid’s during the formation of the double seam.  If the cover hook is incorrect – this can lead to bad seams, bad overlap and ultimately a serious defect. Cover hook can be measured indirectly after a teardown procedure, or directly through a seam inspection system SEAMetal & SEAMscan by cutting or sectioning of the seam with a twin blade saw (or “bread saw”).

Possible causes for Short Cover Hook:

• Loose 1st operation roll
• Long Body Hook
• Countersink is too deep!
• Under-curled end
• Incorrect 1st or 2nd operation setup

Possible causes for Long Cover Hook:

• Tight 1st operation roll
• Short Body Hook
• Countersink is too shallow (not deep enough)!
• Over-curled end
• Incorrect 1st or 2nd operation setup