Specification
Material: zinc alloy
Color: Silver
Size:1/4 inch x 1-1/2 inch
Guide hole drilling size:1/2 inch, please check the size again before purchase.
Tap the insertion hole with a hammer until flush, then screw in the screw, the bolt will spread the tension cover to the sides making the screw easier to screw in.
Allows square head screws to be installed into concrete, brick, block or masonry structures; suitable for medium-sized projects, shelves, window frames and ductwork.
Package includes: 20 expansion screw shrouds