Smith & Wesson K Frame Model 18-3 Strain Screw, Blue Steel, Square Butt, Old Style, Used, Part# 18173

Smith & Wesson K Frame Model 18-3 Strain Screw

A genuine used Smith & Wesson strain screw pulled from a Model 18-3 revolver. The strain screw controls mainspring tension, directly affecting trigger pull weight and hammer strike force — a small part with a big impact on your revolver's performance. This blue steel, old-style square butt variant is the correct replacement for restoring your K Frame .22 LR to factory specification.

• Compatibility: Smith & Wesson K Frame — Model 18-3
• Caliber: .22 Long Rifle (rimfire)
• Finish: Blue Steel
• Frame Style: Square Butt
• Style: Old Style
• Condition: Used, original factory part
• Part Number: 18173

Note: Strain screw tension affects trigger pull and ignition reliability. Use the correct part for your specific frame style (square vs. round butt) to ensure proper fit and function.