4-40 X 3/4 FLAT SHCS ALLOY
Description
Low-profile, 82° countersunk head. Alloy zinc plated flat head socket cap screws are ideal for applications requiring a strong, corrosion-resistant fastener with a flush mount. Length is measured from the top of the head
Material
Screws shall be made from alloy steel per ASTM F835
Hardness
½” diameter and smaller HRC 39-45 Over ½” HRC 37-45.
Zinc
Zinc electroplating is a corrosion-resistant coating that slows rusting by keeping out the moisture lingering in air molecules. It has a high-temperature tolerance of up to 120 and can be useful for applications requiring aesthetic details. The finish is smooth and silvery blue. Coated fasteners are RoHS compliant (hexavalent chromium-free).
Screws are baked within 1 hour after plating for 14 hours to reduce susceptibility to Hydrogen Embrittlement. HE is unpredictable. All plated lots are thoroughly tested prior to sale to further reduce incidence.