The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-180-0372, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Piper Industrial Manufacturing Company, Llc Div Piper Industrial Manufacturing Company. Government technical data includes 22 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-00-180-0372 |
| Primary Part Number | 402 437 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Piper Industrial Manufacturing Company, Llc Div Piper Industrial Manufacturing Company |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES GRIP |
| Surface Finish | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.234 INCHES MINIMUM AND 0.266 INCHES MAXIMUM IN |
| Fastener Length | 3.969 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-P-416 TYPE 2 CLASS 3 FED SPEC ALL TREATMENT RESPONSES OVERALL |
| Thread Length | 0.657 INCHES MINIMUM IN |
| Hardness Rating | 26.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.106 INCHES NOMINAL FIRST HOLE IN |
| Material Document and Classification | MIL-S-6049 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-6050 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6098 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 4TH MATERIAL RESPONSE OR MIL-S-6758 MIL SPEC 5TH MATERIAL RESPONSE OR AMS 6300 ASSN STD 6TH MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.437 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 3.312 INCHES NOMINAL IN |
| Width Between Flats | 0.615 INCHES MINIMUM AND 0.627 INCHES MAXIMUM IN |
| Grip Diameter | 0.4362 INCHES MINIMUM AND 0.4367 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 125000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | STEEL COMP 8740 OR STEEL COMP 8630 OR STEEL COMP 8735 OR STEEL COMP 4140 OR STEEL COMP 4130 OR STEEL COMP 4037 OVERALL |
| Thread Series Designator | UNF |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 3.796 INCHES NOMINAL FIRST HOLE IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 402 437 | Piper Industrial Manufacturing Company, Llc Div Piper Industrial Manufacturing Company (USA) |
| Reference | Meaning |
|---|---|
| AN177-37 | 2/2 Government specification standardization U.S. Government activity |
| B6812 | 4/1 Identification reference U.S. Government activity |
NSN 5306-00-180-0372 is a Bolt,close Tolerance, manufactured by Piper Industrial Manufacturing Company, Llc Div Piper Industrial Manufacturing Company, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-180-0372 has 1 manufacturer part number on file: 402 437 (Piper Industrial Manufacturing Company, Llc Div Piper Industrial Manufacturing Company).
Key specifications for 402 437: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.234 INCHES MINIMUM AND 0.266 INCHES MAXIMUM IN; Fastener Length: 3.969 INCHES NOMINAL IN. 22 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.