The Countersink, cataloged under National Stock Number 5133-00-253-5469, is classified within Federal Supply Class 5133 (Drill Bits, Counterbores, and Countersinks: Hand and Machine) of the Hand Tools group. Government technical data includes 9 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5133-00-253-5469 |
| Item Name | Countersink |
| FSC / FSG | 5133 / 51 — Drill Bits, Counterbores, and Countersinks: Hand and Machine |
| Status | ACTIVE |
| Shank Diameter | 0.250 INCHES NOMINAL IN |
| Body Diameter | 0.438 INCHES NOMINAL IN |
| Cutting End Style | STRAIGHT FLUTE POINT END |
| Hardness Rating | 40.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM |
| Cutting Rotation Direction | RIGHT-HAND |
| Shank Style | STRAIGHT ROUND |
| Flute Quantity | 3 |
| Included Angle | 100.0 DEGREES NOMINAL |
| Material | STEEL OVERALL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| MM312-4 | 3/1 Design control — primary reference Martin Aircraft Tool Company |
NSN 5133-00-253-5469 is a Countersink, classified under FSC 5133, Drill Bits, Counterbores, and Countersinks: Hand and Machine. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5133-00-411-2333. Verify interchangeability with system specifications before substitution.
Key specifications for 5133-00-253-5469: Shank Diameter: 0.250 INCHES NOMINAL IN; Body Diameter: 0.438 INCHES NOMINAL IN; Cutting End Style: STRAIGHT FLUTE POINT END; Hardness Rating: 40.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM. 9 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.