The Clamp,block, cataloged under National Stock Number 5340-01-257-5231, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 15 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active. Unit of issue: EA.
| Parameter | Value |
|---|---|
| NSN | 5340-01-257-5231 |
| Primary Part Number | 68A690879-2015/2017/2019 |
| Item Name | Clamp,block |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Mounting Hole Quantity | 22 |
| Clamping Hole Quantity | 55 |
| Center to Center Distance Between First and Fourth Clamping Holes | 2.133 INCHES NOMINAL IN |
| Block Height | 0.250 INCHES MINIMUM AND 0.250 INCHES MINIMUM AND 0.255 INCHES MAXIMUM0.255 INCHES MAXIMUM IN |
| Style Designator | RECTANGULAR |
| Material Document and Classification | MIL-P-15035 MIL SPEC SINGLE MATERIAL RESPONSE |
| Clamping Hole Diameter | 0.391 INCHES MINIMUM AND 0.395 INCHES MAXIMUM FOURTH HOLE IN |
| Clamping Hole Diameter | 0.391 INCHES MINIMUM AND 0.395 INCHES MAXIMUM SECOND HOLE IN |
| Clamping Hole Diameter | 0.391 INCHES MINIMUM AND 0.395 INCHES MAXIMUM THIRD HOLE IN |
| Center to Center Distance Between First and Third Clamping Holes | 0.600 INCHES MINIMUM AND 0.602 INCHES MAXIMUM IN |
| Distance From Center of Mounting Hole to Edge Along the Width | 0.205 INCHES MINIMUM AND 0.205 INCHES MINIMUM AND 0.211 INCHES MAXIMUM0.211 INCHES MAXIMUM IN |
| Mounting Facility | UNTHREADED HOLE(S)UNTHREADED HOLE(S) |
| Center to Center Distance Between First and Fifth Clamping Holes | 3.060 INCHES MINIMUM AND 3.064 INCHES MAXIMUM IN |
| Material | PLASTIC |
| Center to Center Distance Between First and Second Clamping Holes | 0.870 INCHES MINIMUM AND 0.874 INCHES MAXIMUM IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Unit of Issue | EA |
| Part Number | Manufacturer |
|---|---|
| 68A690879-2015/2017/2019 | Plastifab, Inc. Dba Plastifab Leed Plastics Div Plasifab Inc. (USA) |
| 68A690879-2015/2017/2019 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| 68A690879-2015/2017/2019 | 5/9 Secondary reference Plastifab Incorporated |
| 68A690879-2019 | 5/9 Secondary reference The Boeing Company Div Defense |
| 68A690879-2015 | 5/9 Secondary reference The Boeing Company Div Defense |
| 68A690879-2017 | 5/9 Secondary reference The Boeing Company Div Defense |
NSN 5340-01-257-5231 is a Clamp,block, manufactured by The Boeing Company Div Defense, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-01-257-5231 has 2 manufacturer part numbers on file: 68A690879-2015/2017/2019 (Plastifab, Inc. Dba Plastifab Leed Plastics Div Plasifab Inc.), 68A690879-2015/2017/2019 (The Boeing Company Div Defense).
Key specifications for 68A690879-2015/2017/2019: Mounting Hole Quantity: 22; Overall Height: 0.758 INCHES NOMINAL0.758 INCHES NOMINAL IN; Clamping Hole Quantity: 55; Center to Center Distance Between First and Fourth Clamping Holes: 2.133 INCHES NOMINAL IN. 15 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). 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.