Do you offer stock services for large quantity orders?

Yes, our warehouse provides specific stock services for long-term business. You can schedule shipments on an annual or monthly basis.

Black Oxide 3 1/4" Outer Diameter Long Coil Eod Torsion Spring Factory

Name: Black Oxide 3 1/4" Outer Diameter Long Coil Eod Torsion Spring Factory
Brand: Yueqing Dofo Spring Manufacturing Co., Ltd.
SKU: 1902248225

Zhejiang, ChinaYueqing Dofo Spring Manufacturing Co., Ltd.

US$0.20-1.20

10,000 Pieces

Sample price:US$80.00/piece.Request sample

Product profile

Customization

Available

Function

Pressed, Buffer

Material

Steel

Model NO.

DF2103483

Usage

Industrial, Auto, Motorcycle, Home Appliance

Load Type

Torsion

Production Process

Cold Roll

Shape

Coil

Product Name

Oed Torsion Spring

Business Mode

Factory OEM

Material Standard

GB 4357-09 or Equivalent

Wire Range

From Min 0.1mm(0.004inch) to Max 12mm(0.48inch)

Winding Direction

Left and Right

End Type

Single Torsion

Surface Treatment

Black Oxide

Coating Thickness

8~10 Micrometer

Testing Method

Random Sample Inspection

Tolerance

GB Standard, Grade II or as Per Your Requirement

Spring Rate Tolerance

+-3%~10%

Aql Level

Aql 1.0

Packing Method

OPP Bags with Blank Carton

Normal Carton Size

23X23X31/Cm with No Mark

Certificate

ISO9001, SGS, RoHS, CE, Ts16949

Transport Package

Carton and Outer Wooden Case

Specification

customized

Trademark

DOFO

Origin

Wenzhou, China

HS Code

7320909000

Production Capacity

1, 000, 000 Pieces Per Month

Key features

RoHS Compliant Materials: All materials including carbon steel and stainless steel comply with RoHS standards.

Custom Design Support: Engineers provide CAD/3D/2D design assistance and prototype development services.

Flexible Order Quantities: We accept both small quantity and large run orders based on customer demand.

Sample Charge Refund: Custom spring sample charges are refunded upon placement of the formal order.

Fast Lead Time: Standard springs delivered within 25 days; complex shapes take 30-40 days.

Professional QA/QC: 100% visual and functional inspection with 8 dedicated QA/QC inspectors.

Multiple Payment Options: Accept T/T, L/C at sight, DP, PayPal, Western Union, and small-amount payments.

Long-Term Stock Service: Warehouse provides specific stock services for long-term business partners.

Company profile

High Repeat Buyers ChoiceIn-stock Capacity100% Finished Products InspectionQuality Assurance

Yueqing Dofo Spring Manufacturing Co., Ltd.

Zhejiang, China

CertifiedBusiness Type: Manufacturer/Factory & Trading Company CertifiedR&D Capacity: ODM Service Available CertifiedCustomization Options: Customization from Samples, Customization from Designs, etc. CertifiedExport Year: 26 Years CertifiedNearest Port: Ningbo PortAverage Response Time: ≤0.29h

AI-Powered supplier vetting

SummaryThe supplier presents itself as a professional technical supplier with 3D design, R&D, ODM, and broad customization capabilities. It reports structured production, testing, packing, quality-control, traceability, corrective-action, and complaint-handling procedures, as well as valid contracts with associated subcontractors and inventory capability. Export experience is stated at 26 years, with self-operated import/export rights and 21%–30% of sales from exports. However, it has no overseas warehouse, showroom, agents, or branches, and reports no offline trade-show participation. Certification holdings are explicitly described in the company profile, but current validity is not independently established. Financial credibility cannot be assessed because the supplied financial fields contain zero values. Customer cases and named customer references are not provided.

Supplier typeThe supplier is explicitly identified as a professional technical supplier and describes a mature structure covering management, design, production, testing, and packing. It also has valid manufacturing contracts with associated subcontractors and self-operated import/export rights, supporting classification as a manufacturing-oriented technical supplier.

CertificationsThe company description states that it obtained ISO9001, TS16949, ISO14001, OHSAS18001, and BV certification. The slice does not provide certificate numbers, validity dates, or verification records, so the assessment is based on the supplier’s stated holdings.

After-Sales capabilityThe supplier reports clear procedures and followed records for corrective and preventive actions and customer complaints, plus quality assurance and material traceability. However, it has no overseas agents or branches, overseas warehouse, or showroom, which limits local service infrastructure.

R&D capabilityThe supplier reports R&D capability, new products in the past year, 3D software design services, and ODM services. It does not have an available SDK and does not provide OEM services for popular brands, but those limitations do not negate the stated product-development capabilities.

Production capacityEvidence includes valid contracts with every associated subcontractor, inventory capability, one-month average lead times in both peak and off-seasons, 20 qualified service-capability suppliers, standardized finished-product inspection instructions, and established production and testing structures. The supplier also reports 26 years of export experience and self-operated import/export rights.

Customization capabilityThe supplier explicitly offers customization from samples, customization from designs, full customization, minor customization, and flexible customization, together with 3D design and ODM services. This indicates broad design-to-production customization coverage.

Product Q&A

Q:Which materials are available and do they meet RoHS certification?

We manufacture compression, extension, torsion springs, and wire forms using high-grade spring steel, carbon steel, stainless steel, and music wire. All materials comply with the RoHS standard.

Q:Do you support small quantity orders or only large runs?

We support both small quantity and large run orders based on your demand. We work with you to choose the most effective solution.

Q:Does DOFO spring offer design service or initial assistance on springs?

Our engineers provide initial design assistance to lower production costs. We offer CAD, 3D, and 2D design layouts as well as prototype development.

Q:What is the typical lead time for custom springs?

For springs in our mold range, delivery is within 25 days. For complex shapes, the delivery time is around 30-40 days.

Q:Do you charge for custom spring samples?

Sample charges are refunded when we receive the formal order. However, if the sample requires an additional mold, we will charge for it.