Spotted a couple of these tag-like objects around the Hoover Dam. What are they for?
Answer: They’re survey markers or plaques used for monitoring settlement or movement. They sometimes are retro reflective and a surveyor with a theodolite either manual or automatic will check the distance of the survey plaque.
-1
1.
Member 5 year s ago
#3 is a reamer - when a hole is drilled into metal and you want the hole larger, you would ream this bit in and out to enlarge it.
1
2.
Carwash 5 year s ago
Member no it isn't. It is a screw extractor for broken screws or bolts. Note the threads turn left handed in order to get a tighter grip in an anti clockwise direction
after drilling a hole inside the screw. A reamer has sharp ridges and are set in a clockwise direction
after drilling a hole inside the screw. A reamer has sharp ridges and are set in a clockwise direction
after drilling a hole inside the screw. A reamer has sharp ridges and are set in a clockwise direction