garage door spring

1. we can make it according to your drawings or specifications

2. materil: spring steel, steel, stainless steel, carbon stell, Mn-steel and so on

3. surface finish: znc/chrome/nickel plated, plaint black

4. with high quality and good service

5. if any requirments, pls email us

Summary: Extension spring is one of our main products. We accept OEM orders. We can produce various of extension spring with different hooks, such as long loop, German hook, British hook and side hook. Our extension springs are with diameter from 0.2mm to 20mm. These extension springs are widely used.

Material: usually use spring steel, carbon steel, stainless steel, music wire, alloy steel, etc.

Wire diameter: we can produce extension spring with wire diameter from 0.2mm to 20mm

Surface: usually oiled, shot peening, galvanization, nickel plating, chroming, powder coating, etc.

Technical parameters & procedure:

Before sampling or producing, we need to know some important factors, such as material, wire diameter, outer diameter, inner diameter, free length, hook radius etc. or technical drawing.

Usually we produce extension spring as below steps: winding, making hooks, grinding, shaping, quenching, stereo type, dynamometry, surface treatment, inspection and packing. The technical details and procedure are very different based on different springs request

Packing: usually packed by sack or cartons. We can do according to buyer's requests.

QC/quality control:

We passed ISO9001:2008 international quality system.

Before producing, we have confirmed technical drawing and approved samples. And we have pre-production meeting.

When producing, we checked every 15 minutes for every steps by professional.

Before packing, we tested and checked all products. If OK, will packe

Application: Our extension springs are widely used in computer, electron, home appliances, camera, instrument, motorcycle, automobile, engineering machinery, mining machinery, construction machinery, and other industry.

Lead-time: usually 7-10 working days for samples, 25-30 working days for production. The correct lead-time would base on your exact orders.

Minimum quantity: usually 5000-10000pcs

Payment terms: total amount below or equal to USD5000.00, 100% T/T in advance

             Total amount above USD5000.00, 50% T/T in advance, 50% T/T before shipment

Delivery terms: usually FOB shanghai or ex-works;