Keystone Electronics 8440D 4-40 Female-Female Hex Standoff
A 5/8-inch 4-40 female-female hex standoff molded in natural Nylon 6/6 with a UL 94V-0 rating.
Product Profile
8440D is a Keystone Electronics threaded nylon standoff for spacing printed-circuit boards or small assemblies. Both ends are female threaded and the hex body supports controlled installation with standard hand tools.
Its part number fixes the 4-40 thread, 0.625-inch length and Nylon 6/6 V-0 material variant.
Technical Data
| Manufacturer | Keystone Electronics |
|---|---|
| Part Number | 8440D |
| Component Type | Female-female threaded standoff |
| Thread | 4-40 UNC |
| Length | 0.625 in (15.9 mm) |
| Outside Dimension | 0.250 in (6.4 mm) hex |
| Material | Nylon 6/6, natural |
| Flammability Rating | UL 94V-0 |
| Threaded Ends | Both ends |
| Packaging | Bulk component |
System Role
- Electrically insulating Nylon 6/6 construction.
- Hex profile for tool access during assembly.
- Female threads at both ends for screw-fastened PCB spacing.
- V-0 flammability-rated material within the manufacturer series.
Compatibility
- Use with 4-40 screws and mounting holes arranged for a 0.250-inch hex body.
- Do not substitute 8440A, 8440B, 8440C or 8440E without checking the changed length.
- Validate mechanical load and environmental limits in the finished equipment.
Applications
- Printed-circuit-board spacing inside control electronics.
- Lightweight insulated separation of terminal or display assemblies.
- Service replacement where 4-40 hardware and 5/8-inch spacing are documented.
FAQ
What spacing does 8440D provide?
8440D provides a nominal 0.625-inch (15.9 mm) board-to-board or board-to-panel separation.
Are both ends of 8440D threaded?
Yes. 8440D is a female-female standoff with 4-40 threads at both ends.
What material is used for 8440D?
Keystone specifies natural Nylon 6/6 with a UL 94V-0 flammability rating.
Can 8440D be replaced by another 8440 suffix?
Only after confirming the length; the letter suffix changes the standoff height within the series.
How should 8440D be tightened?
Use suitable 4-40 hardware and conservative torque so the nylon threads and PCB are not damaged.
Is 8440D intended as a current-carrying spacer?
No. It is insulating mechanical spacing hardware, not an electrical conductor or terminal.
Recommended Models
| 5TE2 AT | ADVU-80-10-PA | GH R4 3108 00 R1 |
| FH87/II2GD EDRE132S4BE11/3GD/TF/AL | JVT248-1540 | IR425 / ir425-D4-2 |
| X20ZF0000 | EYL0001V0010L02J01 | 3UG4841-1CA40 |
| MINI-PS-12-24DC/5-15DC/2 | XM30 X13651469-01 | ABB TU515 C0 1SAP212200R0001 |
| SGDH-30DE-OY | QL-PS1202 | PXX-L11 |
| SB401-50 | HDL-MSD04T.40 | Helios HighVent KD 400/6/80/50 |
| Woodhead BradPower 1300640448 | Inatec ZP 9720/1 3699 | 6ES7151-3AA23-0AB0 |
| 7XV124.50-12 | D642-284 P02KP6D2CNH | AER1600 BA2-1600LP5-XTL MC400LP5 |
| MXS12-50 | ACU4001A | LEGRAND 03842 |
| RXZE2M114M | 6SC9830-0BA31 | YASKAWA JUSP-0P02A |
