From Family Handyman · Alex Shoemaker · · 40s
Why Plug Prongs Have Tiny Holes
Tiny holes in electrical plug prongs keep them from slipping out of outlets.
In brief
Tiny holes in electrical plug prongs keep them from slipping out of outlets. Holes in plug prongs prevent slipping, but modern outlets grip prongs securely without them. Originally reported by Family Handyman.
Why Plug Prongs Have Small Holes
Holes originally kept plugs from slipping out of older outlets with bumps.
“Most manufacturers stopped putting the detent nibs on the female contacts, as it made it much harder to meet the maximum force to withdraw and did nothing for the minimum requirement, as the gage had no holes”
Modern Outlets Grip Prongs Securely
Newer outlets hold plugs without bumps, so holes are no longer needed.
Holes Don't Help Safety
Holes aren't child safety features; tamper-resistant outlets use built-in shutters instead.
“TRRs work like normal outlets”
Holes Used for Manufacturing
Manufacturers sometimes use holes to hold prongs during production or for safety tags.
The headline
Holes in plug prongs prevent slipping, but modern outlets grip prongs securely without them.
