Smith & Wesson Multi-Model Auto Pistol Mainspring — New OEM Part 103620000
$8.99
Skip to product information
Smith & Wesson Multi-Model Auto Pistol Mainspring — New OEM Part 103620000
$8.99
Smith & Wesson Multi-Model Auto Pistol Mainspring — New OEM Factory Part
Factory new OEM mainspring (hammer spring) for multiple Smith & Wesson semi-automatic pistols spanning 1st, 2nd, and 3rd generations. This genuine S&W replacement part (part #103620000) powers the hammer to strike the firing pin for reliable ignition in both double-action and single-action modes. A worn or weakened mainspring can cause light primer strikes and misfires — this new OEM spring restores factory-correct trigger function and ignition reliability.
Specifications
- Part Number: 103620000
- Manufacturer: Smith & Wesson
- Part Type: Mainspring (Hammer Spring)
- Calibers: 9mm, .40 S&W, .45 ACP, 10mm
- Generations: 1st, 2nd, and 3rd Generation Semi-Auto Pistols
- Condition: Factory New OEM
Model Compatibility Chart
| Model | Generation | Caliber | Compatibility |
|---|---|---|---|
| Model 39 | 1st Gen | 9mm | ✓ Compatible |
| Model 439, 539 | 2nd Gen | 9mm | ✓ Compatible |
| Model 3904, 3906, 3944, 3946 | 3rd Gen | 9mm | ✓ Compatible |
| Model 5903TSW, 5906TSW, 5943TSW | 3rd Gen TSW | 9mm | ✓ Compatible |
| Model 1006, 1026, 1076, 1086 | 3rd Gen | 10mm | ✓ Compatible |
| Model 4003TSW, 4006TSW, 4043TSW, 4046TSW | 3rd Gen TSW | .40 S&W | ✓ Compatible |
| Model 4553TSW, 4563TSW, 4566TSW, 4583TSW, 4586TSW | 3rd Gen TSW | .45 ACP | ✓ Compatible |
| Model 59, 459, 559, 659 | 1st/2nd Gen | 9mm | ⚠ Verify fit — double-stack frame |
| Model 4506, 4513, 4516, 4526, 4536, 4546 | 3rd Gen | .45 ACP | ⚠ Verify fit — non-TSW variants |
| Model 4003, 4006, 4043, 4046 (non-TSW) | 3rd Gen | .40 S&W | ⚠ Verify fit — non-TSW variants |
| M&P Series (all) | Modern | Various | ✗ Not compatible — striker-fired |
Important Notes
- This listing is for the mainspring only. Other fire control parts, pins, and associated components are sold separately. >li>This mainspring fits a wide range of S&W semi-auto pistols across multiple generations and calibers. Internal fire control parts often interchange within the same frame size/generation regardless of caliber. >li>The TSW (Tactical Smith & Wesson) variants are confirmed compatible. Non-TSW 3rd generation models may share the same mainspring but verify fit before ordering. >li>Mainspring replacement requires frame disassembly. Installation by a qualified gunsmith is recommended. >li>All Smith & Wesson factory parts are subject to availability and may require backorder processing.