Description

Elevator door knife spring 17mm 35mm 41mm 58mm Brief Introduction

Product Name	Elevator door knife spring
Model Number	17mm 35mm 41mm 58mm
Quality	Original.Brand New
Payment	T/T. Paypal. Western Union
Delivery	3-5 Working Days
Packaging	Packed by carton

58mm: Elastic Reset Core from Nanjing Zhuye Elevatorparts

Elevator Door Knife Spring 17mm/35mm/41mm/58mm is a critical elastic reset component for elevator door knife systems, covering four mainstream specifications (17mm, 35mm, 41mm, 58mm—referring to free length) to match different elevator door knife models and door opening/closing force requirements. Installed inside the elevator door knife assembly, it provides stable elastic force to ensure the door knife accurately clamps or releases the door lock roller during elevator door opening and closing, realizing reliable reset of the door knife and ensuring synchronous operation of the car door and landing door. Each specification is tailored to specific scenarios: 17mm for small light-duty door knives (residential villa elevators); 35mm for standard residential/commercial elevator door knives; 41mm for medium-load commercial elevator door knives; 58mm for heavy-duty industrial elevator door knives. Widely compatible with mainstream elevator door systems, these springs are essential for maintaining the stability and safety of elevator door operation. Exclusively supplied by Nanjing Zhuye Elevatorparts, a professional provider of high-quality elevator mechanical components, the Elevator Door Knife Spring 17mm/35mm/41mm/58mm fully complies with international elevator safety standards (EN 81-20, GB 7588) and spring technical specifications (GB/T 1239). Manufactured with premium spring steel and precision forming technology, they feature excellent elastic fatigue resistance, high structural stability, and reliable performance in harsh shaft environments, earning recognition from global elevator maintenance teams.

Nanjing Zhuye Elevatorparts adheres to the core philosophy of “Stable Elasticity, Reliable Reset” and implements rigorous quality control for the 17mm/35mm/41mm/58mm elevator door knife springs. Each unit undergoes multi-stage pre-delivery inspections, including elastic force testing, fatigue life verification, corrosion resistance detection, and dimensional accuracy evaluation. The door knife springs adopt advanced materials and technologies: the spring body is made of high-carbon spring steel (65Mn) with quenching and tempering treatment, ensuring elastic modulus stability and fatigue life of over 1 million times; the surface is treated with galvanizing or electrophoresis, achieving excellent anti-rust performance to adapt to humid and dusty shaft environments (-20℃ to 70℃); the end of the spring is ground flat, ensuring uniform force transmission and avoiding eccentric wear of the door knife assembly; the wire diameter and coil number of each specification are precisely calculated to match the door knife’s load-bearing and reset requirements. The standardized dimensional design enables seamless matching with corresponding door knife assemblies, simplifying selection and replacement.

Step-by-Step Usage Guide for Elevator Door Knife Spring 17mm/35mm/41mm/58mm

To maximize the elastic performance, service life, and operational stability of the Elevator Door Knife Spring 17mm/35mm/41mm/58mm, strictly follow the professional guidelines provided by Nanjing Zhuye Elevatorparts for selection, installation, and maintenance:

1. Professional Selection & Pre-Installation Preparation

Installation must be performed by certified elevator technicians. Prior to selection, refer to the elevator’s door knife model, maintenance manual, or consult Nanjing Zhuye Elevatorparts’ technical team to confirm the correct spring specification (match the free length and wire diameter with the original part). Preparation steps: Cut off the elevator’s main power supply and lock the power switch; place a “Maintenance in Progress” warning sign at the elevator entrance; fix the elevator car door in the fully open position with a mechanical support; disassemble the door knife cover to expose the spring installation position, and clean the assembly area to remove dust, oil stains, and debris.

2. Correct Installation & Elastic Force Calibration

Old Spring Removal: Use pliers (with protective sleeves to avoid damaging components) to gently release the elastic force of the old spring, then take it out from the door knife’s spring groove. Check the spring groove and contact parts for wear, corrosion, or deformation; if there is damage, repair or replace the relevant parts before installing the new spring.
New Spring Installation: Take the matched 17mm/35mm/41mm/58mm door knife spring from Nanjing Zhuye Elevatorparts, apply a thin layer of anti-rust lubricant (recommended by the brand) to the spring surface and installation groove. Align the spring with the positioning pins in the spring groove, and use pliers to slowly compress the spring into the installation position, ensuring it is firmly clamped and does not fall off.
Elastic Force Calibration: After installation, manually simulate the door knife’s clamping and reset process to check if the spring provides stable elastic force—ensure the door knife clamps the lock roller tightly without slipping, and resets quickly without jamming. Use a force gauge to test the door knife’s clamping force (comply with elevator manufacturer’s requirements: 80–120N). Adjust the spring installation position if the force is too large or too small; after calibration, reinstall the door knife cover.

3. Post-Installation Testing & Daily Maintenance

Function Testing: Restore the elevator’s power supply and switch to inspection mode. Operate the elevator door to open and close automatically (≥ 15 times) to verify that the door knife and door lock cooperate smoothly, the door opens and closes synchronously without delay, and there is no abnormal noise. Test the door’s anti-pinch function to ensure it does not affect the safety performance of the door system.
Daily Inspection: Maintenance personnel should check the door knife spring during daily patrols: Observe the spring for deformation, breakage, or rust through the door knife’s inspection hole; check if the door knife resets normally after door opening/closing; listen for abnormal sounds (e.g., creaking) that may indicate spring failure.
Regular Maintenance: Every 3 months, open the door knife cover to clean the spring and installation groove with a soft brush; apply a small amount of anti-rust lubricant to the spring surface. Every 6 months, test the spring’s elastic force—if the elastic force decreases by more than 20% compared to the new spring, prepare for replacement. For elevators in high-traffic or harsh environments, shorten the maintenance interval to 1 month.

Recommended Replacement Cycle for Elevator Door Knife Spring 17mm/35mm/41mm/58mm

As a core elastic component enduring long-term repeated compression, elastic fatigue, environmental erosion (humidity, dust, temperature changes), and mechanical friction, the 17mm/35mm/41mm/58mm elevator door knife spring has a specified service life. Timely replacement is crucial to avoiding faults such as reduced elastic force, permanent deformation, or breakage—issues that may lead to door knife reset failure, inability to open/close the door, or asynchronous operation of car and landing doors, posing serious safety risks to passengers.

1. Standard Replacement Cycle

Under normal operating conditions (elevator daily operation time 12–24 hours, daily door opening/closing cycles ≥ 2000, shaft environment temperature -20℃ to 70℃, humidity 10%–95%), the recommended replacement cycle for all four specifications (17mm/35mm/41mm/58mm) is 1.5–2.5 years. This cycle is determined based on Nanjing Zhuye Elevatorparts’ long-term field operation data, fatigue test results, and global user feedback on elevator door components.

2. Adjustments for Special Scenarios

High-Traffic & Harsh Environments: For elevators in high-traffic locations (e.g., large airports, central shopping malls) with daily door cycles ≥ 3500, or in harsh environments (e.g., high-humidity coastal areas, high-dust industrial sites), the replacement cycle is shortened to 8–12 months. Frequent compression accelerates elastic fatigue, while harsh environments cause rapid rusting and structural damage to the spring.
Low-Frequency Use & Stable Environments: For elevators with low usage frequency (e.g., villa elevators, small office buildings with daily operation time < 8 hours) and stable shaft environments (constant temperature and humidity), the replacement cycle can be extended to 2.5–3 years—only after Nanjing Zhuye Elevatorparts’ technicians inspect and confirm that the spring’s elastic force, dimensional stability, and surface condition meet factory standards.

3. Immediate Replacement Conditions

Replace the door knife spring immediately if any of the following issues occur, regardless of its service life:

The spring has obvious deformation (e.g., bending, flattening) or surface cracks, affecting elastic reset performance.
The elastic force decreases by more than 20% (tested by force gauge), leading to unstable door knife clamping or slow reset.
The spring is severely rusted, with rust spots penetrating the wire diameter or causing stuck operation with the installation groove.
The spring breaks partially or completely, resulting in door knife failure and inability to open/close the elevator door normally.

In conclusion, the Elevator Door Knife Spring 17mm/35mm/41mm/58mm from Nanjing Zhuye Elevatorparts are high-quality, tailored elastic components for different elevator door knife systems. By following the correct selection, installation, maintenance, and replacement guidelines, elevator maintenance teams can effectively ensure the reliable operation of the elevator door system, reduce door failure rates, and enhance passenger ride safety. Choosing Nanjing Zhuye Elevatorparts means you get 100% authentic door knife springs of all specifications, plus professional support—including specification matching, on-site installation guidance, and prompt after-sales service. Trust Nanjing Zhuye Elevatorparts for the elastic reset stability of your elevator door knife system.

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