| SCREW MATERIAL DOCUMENT AND CLASSIFICATION | BS S143D NATIONAL STD/SPEC SINGLE MATERIAL RESPONSE OR AMS 5659 ASSN STD SINGLE MATERIAL RESPONSE |
| SCREW MATERIAL | STEEL CORROSION RESISTING |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.220 INCHES NOMINAL |
| THREAD QUANTITY PER INCH | 56 |
| THREAD SERIES DESIGNATOR | UNF |
| FASTENER LENGTH | 0.245 INCHES MINIMUM AND 0.255 INCHES MAXIMUM |
| FEATURES PROVIDED | FINISHED HEAD |
| HEAD DIAMETER | 0.230 INCHES MINIMUM AND 0.240 INCHES MAXIMUM |
| HEAD HEIGHT | 0.040 INCHES MINIMUM AND 0.050 INCHES MAXIMUM |
| HEAD STYLE | PAN NO. 2 |
| INTERNAL DRIVE STYLE | SLOT |
| III PART NAME ASSIGNED BY CONTROLLING AGENCY | SCREW PAN HEAD 3-56 UNF X 0.25 |
| NOMINAL THREAD DIAMETER | 0.099 INCHES |