Views: 142 Author: Winnie Publish Time: 2026-09-08 Origin: Site
Hinges support almost the full weight of the door leaf, which is frequently underestimated during ordering.
Material choice: Stainless steel hinges are strongly recommended for exterior doors and coastal humid areas for excellent rust resistance. Galvanized hinges are acceptable for dry indoor projects.
Load bearing standard: Heavy security doors and fire rated doors require heavy duty hinges. The quantity of hinges shall match door height and weight. Insufficient or low load hinges will cause door sagging over time, resulting in uneven gaps, hard closing and sealing failure.
Practical test point: Open and close the door repeatedly. Smooth movement without squeaking or loose rotation is required. Hinge surface should be free of burrs, with color consistent with the rest hardware set.
The main lock acts as the centre of the multi point locking system. All auxiliary lock points work based on its linkage.
Lock body structure: Prioritize reinforced thick lock bodies for better anti pry performance. Thin lock bodies are easy to deform under external force.
Function check: Locking and unlocking action must be flexible without jamming. Sample testing across bulk production is necessary to avoid batch inconsistency.
Installation fit: Door cut out size shall perfectly match the main lock body. Wrong cutting will lead to lock malfunction after on site installation.
A single main lock cannot meet high security requirements for residential and commercial entrance doors. Side locks and auxiliary locks add multiple locking points along the door vertical edge.
Side lock: Installed on the vertical side of door leaf. Its bolts extend into door frame once locked, defending forced prying from door side. Widely applied on metal security doors.
Second lock: Works as supplementary locking points. Together with the main lock, they disperse impact force and raise overall security level.
Inspection note: All bolts of side lock and auxiliary lock must extend and retract smoothly. Stuck lock bolts will cause doors unable to open or close normally.
Up and down lock connects with the main lock linkage, delivering lock bolts to the top and bottom of door frame.
Typical applications: Security entrance doors, fire rated metal doors and oversized heavyweight doors.
Working logic: When turning the key or handle, bolts pop out synchronously from top and bottom of door leaf and insert into frame mortises. It improves anti burglary capacity and optimizes door sealing performance.
Key inspection item: Synchronous linkage is critical. Asynchronous or jammed top bottom mechanism belongs to common after sales failure. Full locking cycles need to be tested before shipment.
The lock cylinder is the key operated core part. The security grade of the whole door heavily depends on lock cylinder quality.
Security standard: Different markets enforce varying lock cylinder standards. High security cylinders resist technical picking and drilling attack.
Material & durability: Copper lock cylinders feature better wear resistance. Low cost zinc alloy cylinders tend to break after frequent usage.
Operation test: Insert and rotate keys repeatedly. No sticking or rough turning. Confirm key quantity in bulk orders; missing keys will delay project handover.
When confirming order specifications, a cylinder security grade and hinge load bearing requirement.
Request hardware samples for function testing before mass production, especially for new project bulk orders.
During pre shipment inspection, run full lock unlock cycles. Verify synchronous movement of all lock points including main lock, side lock, auxiliary lock and top bottom lock.
Match hinge material according to project environment; select anti rust stainless steel hinges for coastal high humidity markets.
Quality matched hinges and multi point locking systems reduce your after sales risk and help you build good reputation among local contractors and end customers.
