| THREAD SERIES DESIGNATOR | UNC | 
| THREAD LENGTH | 1.500 INCHES MINIMUM AND | 
 | 1.688 INCHES MAXIMUM | 
| FASTENER LENGTH | 2.422 INCHES MINIMUM AND | 
 | 2.562 INCHES MAXIMUM | 
| MATERIAL | STEEL OVERALL | 
| HEAD STYLE | HEXAGON | 
| THREAD DIRECTION | RIGHT-HAND | 
| NOMINAL THREAD DIAMETER | 0.625 INCHES | 
| THREAD QUANTITY PER INCH | 11 | 
| THREAD CLASS | 2A | 
| MATERIAL DOCUMENT AND CLASSIFICATION | ASTM A449 ASSN STD SINGLE MATERIAL RESPONSE OR | 
 | ASTM A354 ASSN STD SINGLE MATERIAL RESPONSE OVERALL | 
| SURFACE TREATMENT | CHROMATE ZINC OVERALL | 
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | ASTM B633,TYPE 2,CLASS 3 ASSN STD SINGLE TREATMENT RESPONSE OVERALL | 
| HARDNESS RATING | 32.0 ROCKWELL C MINIMUM AND | 
 | 38.0 ROCKWELL C MAXIMUM OVERALL | 
| MINIMUM TENSILE STRENGTH | 150000 POUNDS PER SQUARE INCH | 
| HEAD HEIGHT | 0.378 INCHES MINIMUM AND | 
 | 0.403 INCHES MAXIMUM | 
| WIDTH BETWEEN FLATS | 0.922 INCHES MINIMUM AND | 
 | 0.938 INCHES MAXIMUM | 
| LOCKING FEATURE | PATCH THREADS | 
| FEATURES PROVIDED | FINISHED HEAD | 
| DEPARTURE FROM CITED DOCUMENT | FF-S-85,PARAGRAPH 3.1.6,SELF-LOCKING ELEMENT AND PARAGRAPH 3.4.4 ZINC PLATING | 
| SUPPLEMENTARY FEATURES | MEETS ANSI B18.2.1 TABLE 4 SIZE 5/8 EXCEPT SELF-LOCKING ELEMENT MIL-F-18240 | 
| SPECIFICATION/STANDARD DATA | 81348-FF-S-85 GOVERNMENT SPECIFICATION | 
| NONDEFINITIVE SPEC/STD DATA | 2 TYPE AND | 
 | 10P STYLE AND | 
 | 5/8-11UNC SIZE | 
| SPEC/STD CONTROLLING DATA |  | 
| MANUFACTURERS CODE | 81348 | 
| NON-DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | FF-S-85 |