| FASTENER LENGTH | 0.312 INCHES NOMINAL |
| HARDNESS RATING | 45.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM SECONDARY WASHER |
| HEAD DIAMETER | 0.256 INCHES MINIMUM AND 0.270 INCHES MAXIMUM |
| HEAD HEIGHT | 0.072 INCHES MINIMUM AND 0.082 INCHES MAXIMUM |
| HEAD STYLE | PAN NO. 2 |
| INTERNAL DRIVE STYLE | SLOT |
| MATERIAL DOCUMENT AND CLASSIFICATION | QQ-S-634 FED SPEC 1ST MATERIAL RESPONSE OR 66,1060-1080 FED STD 2ND MATERIAL RESPONSE OR QQ-S-636 FED SPEC 2ND MATERIAL RESPONSE OR MIL-S-7952 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-7952 MIL SPEC 4TH MATERIAL RESPONSE OVERALL |
| MATERIAL | STEEL COMP 1010 OR STEEL OR STEEL COMP 1020 OR STEEL COMP 1025 OVERALL |
| NOMINAL THREAD DIAMETER | 0.138 INCHES |
| PRIMARY WASHER MATERIAL THICKNESS | 0.031 INCHES NOMINAL |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.250 INCHES NOMINAL |
| PRIMARY WASHER STYLE | SPLIT HELICAL RING |
| SECONDARY WASHER MATERIAL THICKNESS | 0.016 INCHES NOMINAL |
| SECONDARY WASHER OUTSIDE DIAMETER | 0.258 INCHES NOMINAL |
| SECONDARY WASHER STYLE | FLAT |
| SECONDARY WASHER RELATIONSHIP TO PRIMARY WASHER | NOT IDENTICAL |
| SPECIAL FEATURES | LOCKWASHER AND WASHER NOT RATED SCREW 55000 POUNDSPER SQUARE INCH |
| SPECIFICATION/STANDARD DATA | 80205-NAS720 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416,CL 3 FED SPEC ALL TREATMENT RESPONSES OVERALL |
| SURFACE TREATMENT | CADMIUM AND CHROMATE OVERALL |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.211 INCHES MAXIMUM |
| THREAD QUANTITY PER INCH | 32 |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL COARSE (UNC) |
| WASHER QUANTITY | 2 |