Fastener Part Standard - Machine Screws
This SAE Part Standard covers selected machine screws manufactured in accordance with American Society for Mechanical Engineers dimensional standards. This SAE standard covers material most often used in ship systems and equipment but its use may be applied wherever fasteners of the covered materials are used. This document permits the fasteners to be identified and ordered by a part identification number (PIN) as defined in this document.
Section 1: Added caution statement about potential hazardous materials.
Section 2: Added new reference standards.
Section 3: Added a Definitions paragraph.
Section 4: Added caution on Black Oxide Coatings. Added requirements for phosphate coatings and zinc/aluminum inorganic coatings. Cadmium coatings are now inactive for new design. Decarburization inspection changed from SAE J121/J121M to ASTM F 2328/F 2328M.
Field 3: Designator H revised to allow indented or non-indented heads; Designators E and U added for trim head screws.
Field 4: Designators C = Combination Cross Recessed and Slotted Drive, N = Hex Head and Hex Washer Head Screws with no internal drives, S = Slotted, T = Six Point Recess and U = Square Recess are added; Designator H = Hex Socket is inactivated.
Field 6: Designator A for Aluminum plating is deleted due to misidentification of the coating. Designators K = Manganese Phosphate Coating, P = Zinc Phosphate Coating, X = Zinc/Aluminum Inorganic Coating-No Chromium Permitted and ZA = Zinc with clear topcoat are added; Z = Zinc Electroplate allows ZA to be furnished; Designator C for Cadmium is inactivated for new design. Hexavalent chrome is now prohibited due to environmental and regulatory concerns.
Table 1: Reformatted CRES Designators to list not more than once. Previous Designator S alloys other than free machining have been removed to Designators S1, S2 and S3. Designator S1 added new alloy 302HQ and previous Designator S alloy XM7 is now identified as 18-9LW. Designator S3 is added and lists alloys 321 and 347 previously listed in Designators S and S1. There is no change to current practice of allowing suppliers to choose the CRES alloy to be provided and this is noted. Hardness range of CRES Designators is been reduced to align with ASTM F 593.
Designator C added copper alloy 260 and hardness range converted from HRF to HRB to reflect industry practice. Designator C1 for copper alloys 462 and 464 is added
Designator G steel expanded alloys range to reflect industry production.
Designator T2 for Titanium Alloy 23 (Ti-6Al-4V ELI) is added.
Permitted coatings column added to table.
Section 4: Informational notes revised and added.
Minor editorial changes, clarifications and corrections made throughout.
Included in: Ground Vehicle Fasteners Subscription Learn More