Tamper Proof Socket Set Screws 18-8 Stainless Steel Commonly used in applications where a screw or bolt head would get in the way of a mechanical partFully threaded with no head projecting past the major diameter of the screw thread. Flush with installation surfaceDesigned to be driven by a special security Allen wrench or bit (Does Not Include Matching Insert Bit)Hex drive with central pin designed to deter vandals and theftHeadless fastener for added security Cup point exerts clamping force through the bottom tip that projects through the hole18-8 Stainless steel for corrosion resistance and durability Socket Set Screws in this selection feature a hex drive with a central pin to prevent installation or removal with a standard hex bit or allen key. Socket Set Screws are used in installations where a flush application surface is important. Set screws are ideal for this type of application because they are headless (blind) fasteners, which means that nothing will protrude above the application surface. Blind fasteners also add another layer of security to a tamper proof assembly. Because they run flush with or even sometimes below the application surface they are less vulnerable to gripping devices such as pliers. Set screws are commonly used in pulleys, tracks, manufacturing, surfboard fins, handles and grips. Product Specifications: Material: 18-8 Stainless SteelDiameter: 1/4"Thread Size: 1/4"-20Thread Type: UNC (Coarse)Thread Pitch: 20 Per InchThread Direction: Right HandDrive Type: Internal Hex (Allen) with PinDrive Size: 1/8" (Tamper Proof)Point Type: CupCup Point Diameter: Max 0.132 - Min 0.118 Tamper Proof Socket Set Screws - 18-8 Stainless Steel 18-8 Stainless Steel Stainless Steel Socket Set Screws, also known as Grub Screws, in this selection are made from grade 18-8 stainless steel. They are corrosion-resistant, durable and suitable for long lasting applications exposed to the elements. 18-8 Stainless Steel is the industry standard for stainless steel fasteners, and ideal for security screws. Tamper Proof Hex Drive with Cup Point Security Screws in this selection feature an internal hex drive style with a central pin making installation or removal difficult (if not impossible) without a matching bit. The drive is designed to deter tampering and vandalism which makes this style of screw popular in public areas including bathroom stalls, gutters, license plates, grills in jails, schools, boats and cars. A cup point is the most common style of set screws, and features a thin edge which digs into the contact surface for high holding power. Headless Design Set Screws are also often used in applications where a flush installation and the look of the final assembly are important, such as furniture assembly. Tamper Proof Socket Set Screws will run flush with the installation surface. They are often plugged after installation for a hidden fastener look. These qualities are what make set screws commonly used in applications where a flat surface is important, such as handles, grips, surfboard fins, and furniture or machine assembly. Because a flush surface is important on complex machines, Set Screws are also commonly used in gears, pulleys, and wheel in machines with moving parts. Additionally, the flush finish adds security to the already tamper resistant design, because without a protruding screw head they are resistant to pliers and other gripping devices.