The lock bolt which is driven by {HEAD ~ the key} to fasten a door, strongbox, etc. has a notch on the slope of the front end thereof to protect against {TAIL ~ insertion} of a pry 
The lock bolt which is driven by { HEAD ~ the key } to fasten a door , strongbox , etc . has a notch on the slope of the front end thereof to protect against { TAIL ~ insertion } of a pry
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH