M5 Retaining Screw Fastening Torque Limits: 3.5 to 4.5 N.m Manual Standard
Engineering Overview: Installation guide specifying M5 cylinder retaining screw torque limits (3.5 - 4.5 N.m) to prevent brass bridge distortion and plug binding.
Technical & Engineering Specifications
| Fastener | Metric M5 x 65 mm / M5 x 75 mm Countersunk Screw |
|---|---|
| Failure Mode | Over-tightening bends central bridge, seizing plug rotation |
| Thread Pitch | M5 x 0.8 mm Standard Metric |
| Recommended Torque | 3.5 - 4.5 N.m (Hand Tighten Only) |
The Over-Tightening Hazard
The lateral M5 metric fixing screw holds the cylinder inside the mortise lockcase.
Fastening Torque Specifications
- Recommended Torque: 3.5 N·m to 4.5 N·m using manual hand screwdrivers.
- Failure Mode of Over-Tightening: Exceeding 6.0 N·m with power drills bends the slender 10 mm brass waist of the cylinder, pinching the internal rotating plugs and causing severe key stiffness or lock seizure.
Frequently Asked Engineering & Selection Questions
Q1: What is the key installation rule for this cylinder?
Installation guide specifying M5 cylinder retaining screw torque limits (3.5 - 4.5 N.m) to prevent brass bridge distortion and plug binding.