The Washer,concave, cataloged under National Stock Number 5310-01-321-8612, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Government technical data includes 11 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-321-8612 |
| Primary Part Number | K52207P7 |
| Item Name | Washer,concave |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Radius | 0.496 INCHES MINIMUM AND 0.501 INCHES MAXIMUM IN |
| Hardness Rating | 38.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM |
| Style Designator | CONCAVE |
| Material Document and Classification | MIL-S-6049 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OVERALL |
| Outside Diameter | 0.863 INCHES MINIMUM AND 0.873 INCHES MAXIMUM IN |
| Recess Depth | 0.075 INCHES NOMINAL IN |
| Material Thickness | 0.170 INCHES MINIMUM AND 0.180 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Material | STEEL COMP 8740 OR STEEL COMP E4340 OVERALL |
| Hole Diameter | 0.592 INCHES MINIMUM AND 0.598 INCHES MAXIMUM 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 |
|---|---|
| K52207P7 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
NSN 5310-01-321-8612 is a Washer,concave, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-321-8612 has 1 manufacturer part number on file: K52207P7 (Howmet Global Fastening Systems Inc).
Key specifications for K52207P7: Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Radius: 0.496 INCHES MINIMUM AND 0.501 INCHES MAXIMUM IN; Hardness Rating: 38.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM; Style Designator: CONCAVE. 11 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.