Product Overview
SourcingProChina is a sourcing agent based in China, connecting overseas buyers with manufacturers of all-metal anti-loosening lock nut assemblies for high-vibration, high-shock, and high-impact applications. The assembly uses a two-piece system (convex nut + concave nut): when the convex (upper) nut is tightened to the specified torque, the concave (lower) nut is driven into full circumferential contact with the bolt thread, creating a positive mechanical lock across a large contact surface.
This mechanism is an alternative to nylon-insert lock nuts, spring washers, and chemical threadlockers. Per Method 1 transverse vibration testing referenced by our manufacturing partners, the assembly retains ≥90% residual clamp load after test cycles [需补充具体检测机构、标准版本及报告编号]. The assembly is designed for repeated installation and removal without replacement of locking elements.
Products are manufactured to metric coarse and fine thread standards, strength grades Class 8 to Class 12, sizes up to M120. Custom grades up to Class 14 and custom materials can be arranged through our sourcing network upon request.
Core Technical Parameters
Strength & Performance
- Strength Grades: Class 8, Class 10, Class 12 (per GB/T 6184-2000 / DIN EN ISO 898-2)
- Max Standard Size: M120 (larger sizes available via custom tooling on request)
- Custom High-Grade: Class 14 available for special applications, subject to manufacturer confirmation
- Residual Clamp Load: ≥90% after transverse vibration testing (Method 1 installation) [需补充具体测试报告来源]
Standards Compliance
- Standard Threads: GB/T 192, GB/T 193, GB/T 197 (DIN EN ISO 7042)
- Fine Threads: GB/T 192, GB/T 193, GB/T 197 (DIN EN ISO 10513)
- Mechanical Properties: GB/T 3098.2-2000, GB/T 3098.4-2000 (DIN EN ISO 2320)
- Surface Finishes: Per DIN EN ISO 4042
Materials Available
10B21, 5+5c, 40Cr, SCM435, 35CrMo, KNDS, 20CrMnTi, plus other customer-specified materials upon request and manufacturer confirmation.
Surface Treatment Options
Zinc plating, hot-dip galvanizing, phosphating, Dacromet, Geomet, zinc-nickel alloy (per DIN EN ISO 4042).
Thread Types
Metric coarse threads (standard), metric fine threads (standard), inch threads (custom), US threads (custom).
Key Advantages
1. Two-Piece Mechanical Locking Design
The all-metal construction creates a mechanical lock through direct contact between the concave nut and bolt thread, rather than relying on a nylon insert or chemical coating. This design is not affected by the temperature or chemical-resistance limitations associated with nylon-insert or adhesive-based locking methods.
2. Documented Anti-Loosening Performance
Transverse vibration testing referenced by our manufacturing partners indicates residual clamp load retention of ≥90% [需补充具体检测机构及报告编号]. Buyers requiring third-party verification can request the test report through our sourcing team.
3. Reusability
Because the locking action relies on the geometry of the convex/concave nut pair rather than a consumable element (e.g., nylon ring, adhesive), the assembly can be removed and reinstalled multiple times. [需补充具体可重复使用次数数据，如有]
4. Sourcing Cost Advantage
As a China-based sourcing agent, SourcingProChina can access factory-direct pricing for comparable specifications. Specific price comparisons against imported brands require product-specific quotation [需补充具体报价对比数据].
5. Custom Engineering Support
Through our manufacturing network, custom sizes beyond M120, higher strength grades (Class 14), and specified materials can be arranged. Feasibility and lead time are confirmed per project after technical review.
Application Scenarios
- Aerospace & Military: vibration-critical assemblies in airframes, avionics mounts, and defense equipment
- Rail Transit & Bullet Trains: bogie connections, track fastening, undercarriage components
- Heavy Industry & Construction Machinery: hydraulic breakers, excavators, crushers, drilling equipment
- Wind Power Generation: turbine tower connections, nacelle assemblies, blade pitch mechanisms
- National Grid Infrastructure: transmission tower bolted connections, substation equipment
- General Heavy Equipment: applications subject to high-frequency vibration, impact loading, or cyclic stress
Frequently Asked Questions
Q1: How does this lock nut design differ from standard nylon-insert lock nuts?
The all-metal two-piece assembly creates a mechanical lock through direct thread-to-thread contact between the concave nut and bolt, rather than friction from a plastic insert. This avoids the temperature and chemical-exposure limitations associated with nylon components.
Q2: Can these lock nuts be reused?
Yes. The locking action comes from the convex/concave nut geometry interacting with the bolt thread, not from a consumable element, allowing reinstallation without replacing parts.
Q3: What strength grades are available?
Class 8, Class 10, and Class 12 per GB/T 6184-2000 are standard. Class 14 can be arranged for select applications, subject to manufacturer confirmation.
Q4: What is the maximum size available?
M120 is the current standard maximum. Larger diameters can be discussed with our manufacturing partners on a custom-tooling basis.
Q5: What test data supports the anti-loosening claim?
Manufacturing partners reference transverse vibration testing (Method 1) showing ≥90% residual clamp load retention. Full test reports are available on request [需补充具体报告来源].
Q6: What surface finishes are available?
Zinc plating, hot-dip galvanizing, phosphating, Dacromet, Geomet, and zinc-nickel alloy, selected according to the corrosion protection requirements of the application environment.
Q7: Can custom thread types be sourced?
Yes, in addition to standard metric coarse and fine threads, inch and US thread configurations can be arranged through our manufacturing network.
Procurement Information
MOQ: Depends on size, grade, and material specification. Contact our team with your requirements for a specific MOQ.
Lead Time: Depends on quantity, customization level, and manufacturer schedule. [需补充具体标准交期区间，如有]
Customization Options: Custom sizes beyond M120; custom strength grades up to Class 14; custom materials; custom surface finishes; custom thread types (inch/US).
Quality Assurance: Manufacturing partners operate under ISO 9001:2015 and IATF 16949 certified quality management systems [需补充具体证书编号]. Each batch undergoes dimensional verification, mechanical testing, and surface finish validation. Test reports are available on request.
Packaging: Standard export packaging with anti-rust protection. Custom packaging and labeling available on request.
Request a Quote
Send your target size, grade, quantity, and application to receive a factory-direct quote and available test reports within [需补充具体响应时效，如'48 hours'] from our sourcing team.
Contact SourcingProChina for a Quote
