Genuine Aircraft Hardware Co. Socket Head Cap Screws NAS1351 (Fine) and NAS1352(Coarse) Lengths may be requested that are less than "Thread Length Min", they will just be fully threaded HELP WITH THE SELECTION OF PART NUMBERS The four numbers after "NAS" denote "Fine" or "Course" Threads Then to designate material add a( - ) for Alloy Steel 180KSI, or a ( C ) for Corrosion Resistant Steel (18-8) 80KSI, or an ( N ) 140-160KSI for Heat Resisting Steel per AMS5731 or 5737 (A286). After the ( - , C, or N) for material, place the Diameter Designation for your desired Shank Diameter that corresponds with your desired Thread Size. After all that but before the Length add Features if desired. After features (if any) then the Overall Features for rotational security. Length is stated in 1/16ths of an inch. The last ( H ) for Drilled Head, or designation is for plating or finish. P= Cadmium II Plating Type 2, class 2, All materials ( LE ) for self locking element any type ( LL ) for self locking element Strip Type S= Silver Flashed for ( C ) and ( N ) materials. ( LN ) for self locking element Pellet Type No Suffix = Black oxide for (Alloy Steel) and Passivated for ( C ) and ( N ) Materials ( LB ) for self locking element Patch Type Example of Part Number: NAS1351-4H14 Socket Head Cap Screw, 1/4-28 Threads, Alloy Steel, Holes in Head , 7/8" Overall Length, Black Oxide Coated. 22 Documents in this book for REFERENCE ONLY, not intended for design. Not guaranteed for accuracy. All Original Text, Tables and Drawings are Copyright (c) by Genuine Aircraft Hardware Co. 2005