Mechanical Performance Requirements

Steel & Stainless Machine Screw Mechanical
Performance Requirements

Description	A straight fastener with external threads designed to go through a hole that is pre-tapped to form a mating thread for the screw.
Applications and Advantages	Machine screws form a fastening superior in strength to spaced thread screws. Zink yellow screws are popular in electronics applications. Stainless steel machine screws are used in applications which require general atmospheric corrosion resistance, in food processing machinery and refrigeration equipment. Stainless is also superior to steel in withstanding some elevation in application operating temperature while maintaining its strength.
Material	Steel: AISI 1006 - 1022 or equivalent steel Stainless: SAE 18-8 stainless steel, passivated
Hardness	Steel: Rockwell B70 - B100 Stainless: Rockwell B85 - B95 (approximate)
Tensile Strength	Steel: 60,000 psi minimum Stainless: 80,000 psi minimum (1000,000 psi after cold working) Machine screws which have a nominal diameter smaller than #4 are not subject to tensile testing. No 4 and No. 5 machine screws which are shorter than 1/2 inch are not subject to tensile testing. Machine screws of diameters No. 6 to 1/2 inch inclusive, which are shorter than either 1/2 inch or 3D (where D is the nominal screw size in inches) are not subject to tensile testing. Such machine screws of a size to be tested shall meet the tensile load requirements given on the thread dimensions page.
Plating	See Machine screw plating specs