BOLT, .25-28,
| MILITARY STANDARDS PROMULGATED BY MILITARY DEPARTMENTS UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M | 96906 |
| TRIUMPH THERMAL SYSTEMS, INC. | 78943 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.554 INCHES MINIMUM AND 0.625 INCHES MAXIMUM |
| FASTENER LENGTH | 0.625 INCHES NOMINAL |
| HEAD STYLE | FILLISTER |
| HEAD DIAMETER | 0.389 INCHES MINIMUM AND 0.414 INCHES MAXIMUM |
| HEAD HEIGHT | 0.161 INCHES MINIMUM AND 0.170 INCHES MAXIMUM |
| HOLE DIAMETER | 0.062 INCHES NOMINAL |
| INTERNAL DRIVE STYLE | CROSS RECESS TYPE 1 |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| HOLE QUANTITY | 1 |
| THREAD QUANTITY PER INCH | 28 |
| MINIMUM TENSILE STRENGTH | 55000 POUNDS PER SQUARE INCH |
| SCREW MATERIAL | STEEL |
| SCREW MATERIAL DOCUMENT AND CLASSIFICATION | QQ-S-633 FED SPEC SINGLE MATERIAL RESPONSE |
| SCREW SURFACE TREATMENT | CADMIUM AND CHROMATE |
| SCREW SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE |
| HEAD HOLE CONFIGURATION STYLE | ROUND |
| THREAD SERIES DESIGNATOR | UNF |
| An externally threaded fastener whose threaded portion is of one nominal diameter, No ( . 6 in./1.5 mm) or larger, designed to be held or driven with either a wrench or an inserted driver or both (excluding internal socket or internal multiple spline types), in sizes below No. 1 ( .19 in./5 mm). No. 1 and larger sizes must have a head designed for any type inserted driver (excluding internal socket or internal multiple spline types), but may also be designed for external wrenching. A locking feature may be incorporated in the design of the head or threads. Excludes BOLT, CLEVIS; BOLT, EXTERNALLY RELIEVED BODY; SCREW, EXTERNALLY RELIEVED BODY; and SCREW, ASSEMBLED WASHER. See also, SCREW, INSTRUMENT; BOLT, MACHINE; BOLT, INTERNAL WRENCHING; and SCREW, CAP SOCKET HEAD. |
