bolts › internal wrenching bolts
MS20004-20
Bolt
Description
Bolt
Specifications
| Country of Origin | USA |
|---|---|
| Fastener Length | 1.735 inches minimum and 1.765 inches maximum |
| Features | Internal Wrenching |
| Grip | 1.250 in |
| Grip Tolerance | ±0.010 in |
| Hardness Rating | 34.0 rockwell c minimum and 40.0 rockwell c maximum |
| Head Diameter | 0.428 inches minimum and 0.438 inches maximum |
| Head Height | 0.250 |
| Head Style | Bevel-conical |
| Head Type | Key Locking |
| Industry Standards/Certification | MS20004 |
| Internal Drive Style | Hexagon |
| Length | 1 3/4 |
| Material | Steel |
| Material Specification | Mil-s-5626 mil spec 1st material response or mil-s-5000 mil spec 2nd material response or mil-s-8503 mil spec 3rd material response or mil-s-6098 mil spec 4th material response or mil-s-6049 mil spec 5th material response |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| NIIN | 00-638-7737 |
| NSN | 5306-00-638-7737 |
| Suggested Nuts for the Bolts | 42FLW |
| Surface Treatment | Cadmium and chromate |
| Surface Treatment Specification | Qq-p-416 type 2 class 3 fed spec all treatment responses |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.475 inches minimum and 0.525 inches maximum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNF |
| Thread Size | 1/4-28 |
| Total Length | 1.750 in |
| Weight | 0.03 lb |
| Width Across Flats | 0.188 inches minimum and 0.190 inches maximum |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
Cross-reference
Similar parts
Parts with matching key dimensions — often from a different standards family. Candidates for comparison only; verify the full specification before substituting.
- MS20004-16 MS 1/4-28 · 0.073 in · Bevel-conical · Steel
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Catalog data updated 2026-07-05. Report a data error