screws › hexagon head cap screws
B1821BH031C138N
Screw
Description
Fastener Length: 1-3/8", Thread: 1/4-18, Thread Length: 0-63/64"
Specifications
| Fastener Length | 1.313 inches minimum and 1.375 inches maximum |
|---|---|
| Features Provided | Finished head |
| Hardness Rating | 32.0 rockwell c minimum and 38.0 rockwell c maximum |
| Head Height | 0.195 inches minimum and 0.211 inches maximum |
| Head Style | Hexagon Head |
| Length | 1 3/8 |
| Material | Steel |
| Material Specification | Sae j429 grade 8 assn std single material response or astm a354 grade bd assn std single material response |
| Min. Tensile Strength (psi) | 150000 pounds per square inch |
| Surface Finish | 63.0 microinches threads |
| Surface Treatment | Zinc and chromate |
| Surface Treatment Specification | Astm b633 ty 2 sc 3 assn std single treatment response |
| Thread Class | 2a |
| Thread Diameter | 0.312 |
| Thread Direction | Right-hand |
| Thread Length | 0.875 inches minimum and 1.062 inches maximum |
| Thread Qty | 18 |
| Thread Qty Per Inch (tpi) | 18 |
| Thread Series Designator | UNC |
| Thread Size | 1/4 |
| Width Between Flats | 0.489 inches minimum and 0.500 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.
- MS90725-36 MS 1/4-18 · 0.073 in · Hexagon Head · Steel
- MS90728-38 MS 1/4-18 · 0.073 in · Hexagon Head · Steel
- B1821BH031C125N Other 1/4-18 · 0.073 in · Hexagon Head · Steel
- B1821BH031C150N Other 1/4-18 · 0.073 in · Hexagon Head · Steel
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Catalog data updated 2026-07-05. Report a data error