Smith & Wesson K Frame Strain Screw Square Butt Blue Steel Old Style - Used - 173G
Smith & Wesson K Frame Strain Screw — Square Butt, Blue Steel, Old Style
This factory original strain screw is a small but critical component in your K Frame revolver. It threads into the grip frame and bears against the mainspring, allowing you to tune trigger pull weight — tightening increases spring tension for more reliable ignition, while backing it out slightly reduces pull weight for competition use.
Pulled from a Model 17-3 .22 LR revolver, this old-style blue steel screw fits all K Frame square butt models regardless of caliber.
What's Included
- Strain screw (blue steel)
Specifications
- Part Number: 173G
- Condition: Used, fully functional
- Frame: K Frame
- Grip Frame: Square butt
- Finish: Blue steel
- Style: Old style
- Source Model: Model 17-3 (.22 LR)
Model Compatibility
| Model | Frame | Caliber | Grip | Notes |
|---|---|---|---|---|
| Model 10 | K Frame | .38 Special | Square Butt | Verify old-style fit |
| Model 12 | K Frame | .38 Special | Square Butt | Verify old-style fit |
| Model 13 | K Frame | .357 Magnum | Square Butt | Verify old-style fit |
| Model 14 | K Frame | .38 Special | Square Butt | Verify old-style fit |
| Model 15 | K Frame | .38 Special | Square Butt | Verify old-style fit |
| Model 16 | K Frame | .32 Long | Square Butt | Verify old-style fit |
| Model 17 / 17-3 | K Frame | .22 Long Rifle | Square Butt | Source model — direct fit |
| Model 18 | K Frame | .22 Long Rifle | Square Butt | Verify old-style fit |
| Model 19 | K Frame | .357 Magnum | Square Butt | Verify old-style fit |
| Model 48 | K Frame | .22 Magnum | Square Butt | Verify old-style fit |
| Model 53 | K Frame | .22 Jet | Square Butt | Verify old-style fit |
| Model 64 | K Frame | .38 Special | Square Butt | Verify old-style fit |
| Model 65 | K Frame | .357 Magnum | Square Butt | Verify old-style fit |
| Model 66 | K Frame | .357 Magnum | Square Butt | Verify old-style fit |
| Model 67 | K Frame | .38 Special | Square Butt | Verify old-style fit |
Note: Fits K Frame square butt models only. Not compatible with K Frame round butt configurations. Strain screw interchanges across all K Frame square butt models regardless of caliber. This is an old-style part — verify your revolver uses the old-style configuration before ordering.