What are your terms of payment?

We can accept T/T, L/C for general Paypal and Western Union for small orders or sample orders.

What is your packing?

Our packing is 15-25 kg for one carton,36 or 48 pcs cartons for one pallet. One pallet is about 900-960 kg. We can make the customer's logo on the cartons. Or we customized cartons according to customers' requests.

Can we print our own logo?

Yes, we can make it according to your request.

Yes, for big orders, old customer and frequent customers, we give reasonable discounts.

How many screws can you produce per day?

We can produce nearly 200000 to 300000 pcs a day. If you are interested in any of our products, please do not hesitate to contact us for more details.

DIN 557 Carbon Steel Square Nut-Coarse Thread

Name: DIN 557 Carbon Steel Square Nut-Coarse Thread
Brand: Ningbo Oukailuo Hardware Co., Ltd.
SKU: 2277836995

Zhejiang, ChinaNingbo Oukailuo Hardware Co., Ltd.

US$0.005-5.00

50,000 Pieces

Product specifications

Specification

Sample price:US$0.50/piece.Request sample

Product profile

Customization

Available

Material

Carbon Steel / Stainless Steel 304/316

Shape of Head

Round

Model NO.

OKL-175

Surface Finishing

Zinc Plated

Certification

ISO, GS, RoHS, CE

Customized

Product Name

Square Nut

Keywords

Nut

Surface Finish

Zinc Plated (Carbon Steel) / Natural (Stainless St

Diameter Range

3.5mm - 6.0mm

Length Range

13mm - 100mm

Point Style

Sharp Piercing Point

Feature

Corrosion Resistant, Anti-Loosening, High Torque T

Application

Construction, Industrial, Furniture, Woodworking

Transport Package

Standard Packaging or Customized

Specification

Standard Specifications or Customized

Trademark

OUKAILUO

Origin

Zhejiang, China

HS Code

7318150000

Production Capacity

300000000PCS/Year

Key features

Anti-Rotation Design: Square shape fits into square holes or slots, preventing spinning during bolt tightening.

High Torque Resistance: Larger contact area distributes clamping force evenly; less likely to round off under high torque.

Vibration Resistance: Precision-engineered thread geometry with micro-serrations creates mechanical interference locking.

Extended Service Life: Tensile pull-out strength exceeds 1200N; validated through 50,000+ cyclic load fatigue testing.

Customizable Options: Customized product name, surface finish, diameter, length, and point style are available.

100% Quality Inspection: Full-batch dimensional verification, torque validation, and ASTM B117 salt spray testing included.

Easy to Weld: Flat sides make square nuts ideal for welding onto flat surfaces in various applications.

Multiple Material Choices: Available in Carbon Steel (Zinc Plated/Black Oxide/Galvanized) and Stainless Steel 304/316.

Company profile

Importers and ExportersHigh Repeat Buyers ChoiceYears of Export ExperienceODM Services

Ningbo Oukailuo Hardware Co., Ltd.

Zhejiang, China

CertifiedBusiness Type: Manufacturer/Factory CertifiedR&D Capacity: ODM Service Available & OEM Service Available CertifiedCustomization Options: Customization from Samples CertifiedExport Year: 14 Years CertifiedNearest Port: Ningbo Port, Shanghai PortAverage Response Time: ≤4.55h

AI-Powered supplier vetting

SummaryThe supplier is a fastener manufacturer with capabilities spanning R&D, design, production, quality control, and after-sales service. It reports recent new-product development, ODM services, OEM experience with well-known brands, sample-based customization, five production lines, and approximately one-month lead times in both peak and off-peak periods. However, the available evidence also identifies important limitations: no supplier-management certification is listed, service procedures lack records, no overseas warehouse, showroom, agent, branch, or offline trade-show participation is reported, and no factory environmental impact assessment or regular fire drills were reported. Financial information is represented only by year labels, without substantive financial metrics, so credibility cannot be determined from the provided slices.

Supplier typeThe supplier describes itself as a fastener producer covering R&D, design, manufacturing, quality control, and after-sales service. Its reported five production lines and OEM/ODM activities support classification as a manufacturer rather than only a trading or service intermediary.

CertificationsThe supplier-management certification field is explicitly recorded as “NIL,” and no other certification is identified in the provided evidence. This is a stated absence of certification information rather than merely incomplete documentation.

R&D capabilityThe supplier reports new products during the past year, provides ODM services, and has two years of R&D engineer experience in the supplied data. These points support active product development, although the reported absence of an available SDK limits evidence of software or integration-oriented R&D capability.

Production capacityThe supplier reports five production lines, fastener-production experience, CNC machining with micron-level precision, and one-month lead times in both peak and off-peak seasons. Its Ningbo location and access to Ningbo and Shanghai ports further support logistics, although production capacity volume is not quantified.

Customization capabilityThe supplier explicitly offers customization from samples, ODM services, and custom-machined parts using CNC lathes. This provides direct evidence of both sample-based and design-oriented customization capability.

Client casesThe supplier states that it provides OEM services for well-known brands, which is direct evidence of customer experience with recognized-brand projects. However, no customer names, project details, or verifiable case records are provided, so the breadth and quality of its customer portfolio cannot be fully evaluated.

Product Q&A

Q:How about your price?

High-quality products at a reasonable price. Please give me an inquiry, and I will quote you a price for you to refer to at once.

Q:How do you control your quality?

We have our in-house QC daily and advanced optical inspection equipment. You could hire a third party for random inspection.

Q:Could you provide free samples?

For our regular products, we offer free samples. For customized screws, bolts, tooling, and moulding, charges are needed. All free samples do not including its courier charge.

Q:Do you accept small orders?

Sure, we can accept any orders. We keep lots of stock for ALL STAINLESS STEEL FASTENERS and CARBON STEEL FASTENERS, like pan head screws, flat head screws, Phillips screws,torx screws, hex screws, etc.

Q:How about your delivery time?

Generally speaking, if the goods are in stock, we can deliver them within 2-5 days. If the quantity is 1-2 containers, we can give you 25-35 days. If the quantity is more than 2 containers and you are very urgent, we can let the factory prioritize producing your goods.