Trusted Nuts Factory: Threaded, Tested & Shipped Worldwide
Kbear Metal manufactures hex nuts, lock nuts, flange nuts, wing nuts, cap nuts, T-nuts, and weld nuts at scale. Property classes 6 through 12, sizes M3 to M64, finished to match every bolt range we supply.
// Nut Production Spec
Nine nut categories from our production floor
Each runs on dedicated tapping and forming tooling with its own QC checkpoints.
Hex Nuts
The standard finished hex nut for general assembly. Pairs with hex bolts in DIN 933 / 931 configurations.
Hex Jam Nuts
Thin hex nut used as a locking nut against a primary hex nut, or where clearance is limited.
Nylon Lock Nuts
Hex nut with nylon insert that grips the bolt thread and resists vibration loosening.
All-Metal Lock Nuts
Prevailing-torque metal lock nut for high-temperature service where nylon would fail.
Flange Nuts
Integrated washer flange distributes load and reduces vibration loosening on flange surfaces.
Cap / Acorn Nuts
Domed nut that covers exposed bolt threads — decorative and protective for visible assemblies.
Wing Nuts
Two-winged nut for hand tightening without tools. Common in equipment that needs frequent disassembly.
T-Nuts
T-slot nuts for machine tool tables, jig fixtures, and aluminum extrusion frame systems.
Weld Nuts
Hex or square nut with projections for spot welding to sheet metal in automotive body assembly.
Nut sizing and mechanical properties
Reference table for metric hex nut property classes per ISO 898-2.
| Property Class | Tensile Stress (MPa) | Proof Load (MPa) | Typical Material | Mating Bolt Class |
|---|---|---|---|---|
| Class 4 | 510 min | 400 | Low carbon steel | Class 3.6, 4.6, 4.8 |
| Class 5 | 610 min | 500 | Medium carbon steel | Class 5.6, 5.8 |
| Class 6 | 720 min | 600 | Medium carbon steel | Class 6.8 |
| Class 8 | 830 min | 800 | Medium carbon, heat treated | Class 8.8 |
| Class 10 | 1040 min | 1000 | Alloy steel, Q&T | Class 10.9 |
| Class 12 | 1150 min | 1150 | Alloy steel, Q&T | Class 12.9 |
| A2-70 (SS 304) | 700 min | 450 | Stainless steel 304 | A2-70 bolts |
| A4-80 (SS 316) | 800 min | 600 | Stainless steel 316 | A4-80 bolts |
Material grades for every service environment
Match nut alloy to mating bolt and operating environment.
Q235 · C45
Standard nuts up to Class 8
35K · 40Cr · SCM435
Class 10 and 12 high-strength
304 · 316 · 316L
A2 and A4 grades
H62 · H59
Plumbing, electrical, decorative
6061 · 2024
Lightweight assembly
C65500 Silicon
Marine hardware
Inconel · Monel
Chemical and high-temp
17-4PH · Titanium
Aerospace, severe service
How a nut becomes a finished part
Six stages from hex bar stock to packed export carton.
Wire / Bar Stock
Hex bar or coiled wire inspected against mill certs.
Cold Forming
Multi-station presses form the hex profile and pilot hole.
Tapping
Internal thread tapped to 6H or 2B class on multi-spindle machines.
Heat Treatment
Quench and temper for Class 8, 10, 12 mechanical properties.
Surface Coating
Zinc plating, galvanizing, black oxide, or specialty finish.
QC & Pack
Thread gauging, proof-load test, packing for export.
Nuts that fit the first time, every time.
Every batch ships with proof-load test certificates, dimensional inspection reports, and material certs. Third-party SGS or BV verification on request.
Proof Load Testing
Each nut grade verified to the proof load specified in ISO 898-2 — no slip, no thread deformation.
Thread Gauging
Go / no-go plug gauges check 6H thread fit on every shift across every tapping line.
Hardness Testing
Rockwell hardness verified after heat treatment to confirm Class 8, 10, 12 properties.
Salt Spray Testing
Coated nuts run through ASTM B117 cycles to confirm corrosion-resistance targets.
Industries that source nuts from our leading factory
Each market has its own standards, finishes, and documentation requirements.
Construction
Heavy hex nuts, structural nuts paired with A325 / A490 bolts.
Automotive
Flange nuts, weld nuts, and lock nuts for chassis and body assembly.
Wind Energy
Tower flange nuts in HDG and Geomet finishes.
Oil & Gas
A194 grades 2H, 7, 8 heavy hex nuts for flange connections.
Marine
316L stainless and silicon bronze nuts for offshore service.
Machinery
T-nuts, lock nuts, and flange nuts for equipment assembly.
Furniture
Tee nuts, barrel nuts, and decorative cap nuts.
Aerospace
17-4PH and titanium lock nuts for severe-service assemblies.
Why distributors choose Kbear for nuts
Six factory-direct advantages that compound across nut and bolt orders.
Matched bolt-nut pairs
Order bolts and nuts from one factory — guaranteed property class and thread fit.
In-house tapping
Multi-spindle tapping machines run 6H metric and 2B inch threads at high volume.
Hex bar inventory
Stock material lets us start small batches without long mill lead times.
Mixed-SKU shipping
Pool nuts with bolts, washers, and screws in one container.
Lock nut options
Nylon, all-metal, and prevailing-torque designs in stock or made-to-order.
Documentation
Material certs, proof-load reports, and AQL inspection bundled per batch.
Inside our nut professional production lines
Multi-spindle tapping machines, cold-forming presses, and dedicated nut QC stations across the factory floor.
Watch nuts being made
Three short videos showing hex forming, thread tapping, and final inspection of finished nuts.
Cold Heading to Thread Rolling
Hex bar stock cold-formed into nut blanks, then internal threads tapped on multi-spindle machines.
Inspection & Testing Process
Proof-load testing, thread go/no-go gauging, and hardness checks for Class 8, 10, 12 nuts.
Packing to Container Loading
Finished nuts counted, bagged or boxed, and palletized for container shipment.
Free Samples
Standard fastener samples shipped free for evaluation. You only cover express courier cost.
First-Order Inspection
Third-party SGS or BV inspection on your first order at our cost — verify before paying balance.
30% Deposit Only
T/T 30% deposit gets your order into production. 70% balance after pre-shipment inspection.
Quality Replacement
Any defect outside agreed AQL gets replaced free on the next shipment, no questions asked.
Common questions on nut sourcing
Quick answers on standards, locking options, and finishes.
What is the difference between Class 8 and Class 10 nuts?
What kind of lock nuts do you produce?
Do you produce ASTM A194 heavy hex nuts?
What thread class do you produce?
Can you supply nuts with mating bolts?
What surface treatments are available?
Contacts
Kbear Metal Factory
Zhanggezhuang Industrial Pack, Pingdu, China
Head Office
Support
+86 18562662895