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AN507-428R20
Aeronautical Standard Screw
Description
Fastener Length: 1-1/4", Thread: 1/4-28, Thread Length: 1-11/64"
Specifications
| Countersink Angle | 99.0 degrees minimum and 101.0 degrees maximum |
|---|---|
| Departure From Cited Designator | As modified by material,as modified by min tensile strength,as modified by hardness rating |
| Fastener Length | 1.188 inches minimum and 1.250 inches maximum |
| Hardness Rating | 26.0 rockwell c minimum and 32.0 rockwell c maximum |
| Head Diameter | 0.462 inches minimum and 0.507 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | Cross recess type 1 |
| Length | 1 1/4 |
| Material | Steel |
| Min. Tensile Strength (psi) | 55000 pounds per square inch |
| Nondefinitive Specification/Std Data | 3 type and 3c style |
| Screw Material | Steel comp 2330 |
| Screw Material Specification | Sae assn std single material response |
| Screw Surface Treatment | Cadmium |
| Screw Surface Treatment Specification | Qq-p-416,ty 1,cl 3 fed spec single treatment response |
| Thread Class | 2a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 1.179 inches minimum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNF |
| Thread Size | 1/4 |
Cross-reference
Interchangeable
Parts that share a National Stock Number or are listed as an alternate for AN507-428R20 — functionally equivalent.
- MS24693-S300 Listed alternate 1/4-28 · 0.073 in · Flat countersunk · Steel
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Catalog data updated 2026-07-05. Report a data error