NINGBO TOPBOLT METALWORKS CO.,LTD. has specialized in the R&D and batch production of DIN standard lock nuts for over a decade, equipped with dedicated cold forming, automatic nylon pressing and precision tapping production lines. All production processes are formulated referring to DIN985, ISO10512 and ASTM A563 international standards.
We adopt imported high toughness PA66 nylon material for lock ring, which features stable temperature resistance and ageing resistance, avoiding nylon shedding during long-time vehicle bumping and outdoor harsh environment operation. Our DIN985 lock nuts have been exported to Europe, North America, Middle East and Southeast Asia for many years, matched with DIN931 bolts, DIN125 washers to form complete fastening sets for equipment manufacturers and engineering contractors globally. Customized height, thread pitch and surface treatment are available per customer technical drawings for non-standard project demands.
2. Strict Full-Process QC Inspection Standard
2.1 Raw Material Acceptance Check
Carbon steel raw material follows EN10263 standard; stainless steel blanks (304/316) source from certified steel mills in accordance with ASTM A240, complete with official MTR material test reports before warehousing and production. Unqualified raw materials are rejected directly to eliminate hidden quality risks from source.
2.2 Mid-production Real-Time Monitoring
During cold heading forming and internal thread rolling, QC team samples dimensions every 30 minutes to control thread tolerance within DIN standard range. Nylon ring pressing process is monitored by intelligent equipment to ensure uniform compression tightness, neither too loose to lose locking effect nor too tight to block bolt assembly.
2.3 Finished Product Lab Testing
Finished goods pass multi-item tests following ISO898-2 standard: proof load test, locking torque test, high-low temperature ageing test and neutral salt spray test. Zinc plated carbon steel lock nuts reach ≥72h salt spray without rust; passivated 304 stainless ≥500h, 316 stainless ≥1000h salt spray performance, effectively adapting to coastal and high-humidity working conditions.
3. Standard Specification Parameter Table
Inspection Item | Specific Parameter | Executed Standard |
Standard | DIN985, ISO10512 | DIN985 |
Available Material | Carbon Steel(Grade8/10), SS304(A2-70), SS316(A4-80) | ISO3506,ISO898-2 |
Metric Size | M3~M36 | DIN13 coarse thread |
Surface Treatment | Zinc plated, Hot dip galvanized, Passivation, Black oxide | ASTM B633 |
Nylon Material | High-strength PA66, -40℃~120℃ working temperature | Industry PA standard |
Core Feature | Nylon ring self-lock, anti-vibration, anti-loose | - |
Application | Auto chassis, new energy mounting, marine equipment, pump & valve, coastal construction | - |
4. Graded Material Selection Guide for Different Working Conditions
4.1 Carbon Steel DIN985 Lock Nut Application Scenarios
Grade8 zinc plated carbon steel lock nuts are cost-effective choice for indoor general machinery, inland electrical equipment and ordinary mechanical assembly with normal atmospheric environment; Grade10 hot-dip galvanized lock nuts fit open-air inland steel structure, outdoor power equipment to improve rust resistance.
4.2 Stainless Steel 304 & 316 DIN985 Selection Rules
304(A2-70) nylon lock nuts apply to inland food machinery, freshwater pipeline and dry outdoor solar brackets; 316(A4-80) molybdenum-containing stainless lock nuts are required for coastal salt spray areas, ship fittings, offshore wind facilities and chemical equipment with chloride corrosion, greatly extending component service life and lowering later maintenance cost.
4.1 Practical Engineering Case
NINGBO TOPBOLT METALWORKS CO.,LTD. has supplied large batches of DIN985 lock nuts for Southeast Asia coastal new energy photovoltaic projects and European automotive component manufacturers in recent two years. Customer feedback shows zero loosening failure after long-term vibration operation, verifying reliable locking performance.
5. Factory Supply & Export Packaging Specification
As a certified physical manufacturer, NINGBO TOPBOLT METALWORKS CO.,LTD. keeps sufficient safety stock for conventional DIN985 sizes, stock items deliver within 5~10 working days for bulk orders; customized non-standard items are arranged for priority production to shorten lead time.
Packing adopts inner PE plastic bag + export carton, loaded onto fumigation-free pallet for ocean shipment, moisture-proof and rust-proof to prevent damage during long-distance global transportation. Our professional foreign trade team provides real-time order tracking, technical parameter consulting and after-sales service. All products support CE & RoHS certification, we can supply full inspection documents including MTR, torque test report for customer factory audit and customs clearance.
6. FAQ for Global Buyers
Q1: What is the maximum applicable temperature of DIN985 nylon lock nut?
Standard PA66 nylon insert works steadily from -40℃ to 120℃; high temperature resistant customized nylon version available for equipment above 120℃ working environment.
Q2: Can DIN985 replace all plain hex nuts in vibration equipment?
Yes, its built-in nylon anti-loose design solves the loose defect of ordinary DIN934 nut under frequent vibration, the preferred fastener for moving and vibrating components.
Q3: Do you accept small trial order before bulk cooperation?
NINGBO TOPBOLT METALWORKS CO.,LTD. supports small trial purchase for customer quality verification.
