| FASTENER LENGTH | 0.312 INCHES NOMINAL |
| HARDNESS RATING | 39.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL |
| HEAD DIAMETER | 0.176 INCHES MINIMUM AND 0.183 INCHES MAXIMUM |
| HEAD HEIGHT | 0.108 INCHES MINIMUM AND 0.112 INCHES MAXIMUM |
| HEAD STYLE | KNURLED NO. 1 |
| INTERNAL DRIVE STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | 66 FED STD ALL MATERIAL RESPONSES OVERALL |
| MATERIAL | STEEL COMP 302 OR STEEL COMP 304 OR STEEL COMP 305 OR STEEL COMP 316 OR STEEL COMP 384 OVERALL |
| MINIMUM TENSILE STRENGTH | 80000 POUNDS PER SQUARE INCH |
| NOMINAL THREAD DIAMETER | 0.112 INCHES |
| NONDEFINITIVE SPEC/STD DATA | 6 TYPE AND 4-40 SIZE AND 5/16IN. LENGTH AND 3ASSJSEUNC CLASS |
| SPECIFICATION/STANDARD DATA | 81348-FF-S-86 GOVERNMENT SPECIFICATION |
| WIDTH ACROSS FLATS | 0.094 INCHES MINIMUM AND 0.095 INCHES MAXIMUM |
| SUPPLEMENTARY FEATURES | FSCM 80204-ANSI B18.3 TABLE 3 SIZE 4 |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| SURFACE TREATMENT | PASSIVATE OVERALL |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.312 INCHES NOMINAL |
| THREAD SERIES DESIGNATOR | UNC |
| THREAD QUANTITY PER INCH | 40 |