Hillman 5/16-in x 4-in Black Hardened Round -Head Exterior Lag screws 4 -Pack

One-way lag screws, also known as security screws are commonly used in applications where either theft or vandalism is common or expected. Common applications include safes, security gates, public restroom fixtures and enclosures, and other scenarios requiring greater security. Heat-treated and made high quality, this screw meets strict standards having virtually no chance of shearing. This screw is designed with a slotted drive for simple installation with a standard slotted screwdriver. For greater security, the one-way lag screw requires an extraction tool for removal. Use this screw in a pre-drilled hole to prevent snapping.