If we order large quantity springs, will you house the springs, wire forms, and ship to us based on a required basis?

Our warehouse provides specific stock service for long term business. You can make your shipment schedule on an annual, monthly basis. We will ship on a specific schedule.

What payment term do we accept for spring orders?

We could accept payment terms based on T/T, L/C at sight, DP, Westunion.

Heavy Duty Extension Spring for Garden Swing Hammock

Name: Heavy Duty Extension Spring for Garden Swing Hammock
Brand: Yueqing Dofo Spring Manufacturing Co., Ltd.
SKU: 1902969455

Zhejiang, ChinaYueqing Dofo Spring Manufacturing Co., Ltd.

US$0.20-1.00

10,000 Pieces

Sample price:US$80.00/piece.Request sample

Product profile

Customization

Available

Function

Pressed, Buffer

Material

Steel

Model NO.

DF2103540

Usage

Industrial, Auto, Motorcycle, Home Appliance

Load Type

Extension

Production Process

Cold Roll

Shape

Coil

Product Name

Hammock Extension 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

Different Hooks Available

Surface Treatment

Trivalent Zinc Coating

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

8mm*39*113mm

Trademark

DOFO

Origin

Wenzhou, China

HS Code

7320909000

Production Capacity

1, 000, 000 Pieces Per Month

Key features

Comprehensive Customization: Full customization from samples and designs, including wire range 0.1mm-12mm and various hook types.

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

Free Design Assistance: Engineers provide initial design assistance, CAD/3D/2D layouts, and cost-saving advice.

Fast Lead Time: Delivery within 25 days for standard springs, 30-40 days for complex shapes.

Sample Charge Refund: Sample charges are refunded upon receiving a formal order, excluding additional mold costs.

Stock Service Available: Warehouse provides specific stock service for long-term business with scheduled shipments.

Flexible Payment Terms: Accepts T/T, L/C at sight, DP, Western Union, and PayPal.

ISO9001 Certified Quality: Certified by ISO9001, SGS, RoHS, CE, and TS16949 with 100% final inspection.

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: ≤0.32h

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 kind of materials are available? Do they meet RoHS certification?

DoFo Spring is able to manufacture different spring types of compression springs, extension springs, torsion springs, wire forms with a large range of High-Grade Spring Steel - Carbon steel - Stainless steel - Music Wire, all comply to the RoHS standard. The wire diameter is available from 0.001 inches to 0.075 inches, which can meet the requirement of different applications.

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

DoFo Spring manufactures large quantity springs, small quantity springs based on your demand. We will work with you to choose the most effective solution.

Q:Does DOFO spring offer DESIGN service OR initial ASSISTANCE ON SPRINGS?

Our engineers could give initial assistance on the design and advise to lower the production cost. Our engineer has years of experience in spring design. We could provide drawing format in CAD, 3D, and 2D design layout as well as prototype development.

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

The lead time varies in custom springs. For compression springs, extension springs, torsion springs, wire forms in our mold range, we are able to deliver within 25 days. However, for some complex shapes of springs, the delivery time would be around 30~40 days.

Q:Do you charge custom spring samples?

We make the custom springs sample charge as a subscription of formal order. In other words, the sample charge could be refunded when we receive the order. However, if your sample requires an additional mold, we will charge it.