| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 20 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.634 INCHES MINIMUM AND |
| 0.766 INCHES MAXIMUM |
| FASTENER LENGTH | 0.734 INCHES MINIMUM AND |
| 0.766 INCHES MAXIMUM |
| MATERIAL | STEEL COMP 302 OR |
| STEEL COMP 304 OR |
| STEEL COMP 305 OR |
| STEEL COMP 316 OR |
| STEEL COMP 384 OR |
| STEEL COMP XM-7 OVERALL |
| SURFACE TREATMENT | CHROMIUM THREADS |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-C-320 FED SPEC SINGLE TREATMENT RESPONSE THREADS |
| HARDNESS RATING | 80.0 ROCKWELL B MINIMUM OVERALL |
| MINIMUM TENSILE STRENGTH | 80000 POUNDS PER SQUARE INCH |
| MINIMUM YIELD STRENGTH | 30000 POUNDS PER SQUARE INCH |
| HEAD STYLE | FLAT CHAMFER |
| HEAD DIAMETER | 0.365 INCHES MINIMUM AND |
| 0.375 INCHES MAXIMUM |
| HEAD HEIGHT | 0.244 INCHES MINIMUM AND |
| 0.250 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | HEXAGON |
| WIDTH ACROSS FLATS | 0.188 INCHES NOMINAL |
| TEST DATA DOCUMENT | 81349-MIL-P-23199 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.). |
| SPECIAL TEST FEATURES | SPECIAL QUALITY CONTROL TESTING |
| NONDEFINITIVE SPEC/STD DATA | 6 TYPE |
| DEPARTURE FROM CITED DOCUMENT | MATERIAL MUST CONFORM TO SHIPS PARTS CONTROL CENTER SPECIAL QUALITY CONTROL PROVISIONS |
| DEPARTURE FROM CITED DESIGNATOR | AS MODIFIED BY THD CLASS AND FINISH |
| CRITICALITY CODE JUSTIFICATION | ZZZW |
| SPEC/STD CONTROLLING DATA | |
| MANUFACTURERS CODE | 81348 |
| NON-DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | FFS86 |