Smith & Wesson J Frame Model 640-3 Internal Parts Set - Used
This listing is for a used Smith & Wesson J Frame Model 640-3 internal parts set. Factory OEM parts sold as-is.
Keep your Model 640-3 Centennial running smoothly with this genuine Smith & Wesson factory internal parts lot. The Model 640-3 is the stainless steel, fully shrouded hammer (DAO) Centennial J Frame chambered in .38 Special — a popular choice for concealed carry and backup duty use. This set covers key action springs and components for gunsmiths performing action work or spring replacement on this classic carry revolver.
Part Details
- Part Number: JS1391
- Condition: Used
-
Parts Included:
- Mainspring (1)
- Bolt Spring & Plunger (1 set)
- Pin (1)
- Fits: Smith & Wesson J Frame Model 640-3
- Caliber: .38 Special
- Frame: J Frame (Stainless Steel)
- Style: Centennial (fully shrouded hammer, DAO)
- OEM: Smith & Wesson Factory Part
Model Compatibility
| Model | Frame | Caliber | Compatible |
|---|---|---|---|
| Model 640-3 | J Frame (Stainless) | .38 Special | ✅ Yes |
| Model 640 (other dash) | J Frame (Stainless) | .38 Spl / .357 Mag | ⚠️ Verify dash number |
| Model 442 | J Frame (Aluminum) | .38 Special+P | ⚠️ Verify fitment — similar Centennial |
| Model 642 | J Frame (Aluminum) | .38 Special+P | ⚠️ Verify fitment — similar Centennial |
| Model 36 / 60 | J Frame (Steel) | .38 Spl / .357 Mag | ❌ No — exposed hammer models differ |
| Model 342 AirLite | J Frame (Aluminum) | .38 Special+P | ❌ No — different frame material |
Note: Spring dimensions and pin fitment can vary between Model 640 dash numbers due to engineering changes. Always confirm your exact model and dash number before ordering. To find your model number, swing out the cylinder and check behind the yoke on the frame.
Installation
Disassembly and reassembly by a qualified gunsmith is required. Some parts may require fitting. Verify correct action function after installation. Factory replacement parts are manufactured to the same specifications, tolerances, and materials as the originals.
Questions? Shoot us an email or give us a call — we're here for all your S&W needs.