Stainless Steel 18-8 Thumb Screw, Knurled Head, #4-40, 1/2" Length (Pack of 25)

Thumb screws are designed to be tightened and loosened by hand. They come in a variety of head styles, but each includes an easy-grip head which allows for simple "by-hand" installation.Stainless steels are used for their corrosion resistance, high-temperature strength, scaling resistance, and low-temperature toughness. These properties account for their extremely wide use in practically every industry. Austenitic Stainless Steels are alloys of iron and carbon that contain between 16% and 30% Chromium, a maximum of 0.15% carbon, along with Nickel (or Manganese), and other alloying elements. The chromium, which helps develop a passive surface oxide film, provides corrosion resistance in stainless steels. Austenitic Stainless Steels are designated by a 3 digit SAE Stainless Steel Grade beginning with the number 3 (e.g. 304, 316). Another common naming convention for Austenitic Stainless Steels are 18/8, 18/10, 18/0, etc. where the 18 refers to the % of Chromium and 8 to % of Nickel contained in the material.Stainless Steel 18-8 denotes 18% chromium and 8% nickel. Stainless Steel 18-8 can be formed and welded. Stainless Steel 18-8 is typically non-magnetic, though the material can become slightly magnetic when cold worked (cold working refers to altering the physical properties of the material without the use of temperature). Usually found on thumb screws, a knurled surface on the head gives a better gripping surface, making it easier to tighten or loosen fasteners manually. A threaded fastener's size name includes information about the major external diameter, followed by the threads per inch, which indicates if it is coarse or fine. Coarse threads are better when working with brittle materials; they are sturdier and are easier to thread and unthread compared to fine. Coarse threading also allows for thicker coatings and platings.

• Thumb Screws allow for simple "by-hand" installation
• General Purpose Stainless Steel suitable where formability and cost are important considerations
• Knurled head provides extra grip for manual tightening
• Tools not necessary for tightening or loosening
• Coarse threads are better for brittle materials, and will assemble and disassemble more quickly than fine threads