Slider Lock Strength: Slider Lock Strength (拉头锁定力)
The maximum force a locked slider resists before the chain begins to open. It measures the effectiveness of the bridge or pawl and spring inside the slider. Adequate lock strength prevents self-opening under tension, which is critical for trousers, skirts and bags. The test pulls the tapes apart with the slider closed and the puller released. Weak springs, worn pawls or poor tooth fit reduce lock strength.