Spring Manufacturing — Biga, Çanakkale

Who makes them

Metiş Yay is an independent manufacturer of steel springs in Biga, a district of Çanakkale in north-western Türkiye. Production began in 1978; the present plant has been running since 1998. Our main line of work is springs for agricultural implements and machinery, but the coiling line does not discriminate — automotive, white goods and general machinery springs are produced on the same line.

Biga is one of the few places in Türkiye where spring manufacturing is concentrated, with several spring makers in the district. The practical benefit of that concentration is in the supply chain: wire, heat treatment and coating services are all resolved within the same industrial area, which shortens lead times on custom work.

Our location has also shaped what we work on. Biga and its surroundings form a dense forage and cereal growing region, where balers, rotary rakes and seed drills are everyday equipment. That is why our catalogue runs deep in those machine groups — the products were shaped by demand coming in from the field.

What we make

The coiling line works across wire diameters from 0.20 mm to 40 mm. That range covers everything from wire form parts as fine as a clock spring to heavy duty springs on a cultivator leg.

• Compression springs — cylindrical springs compressed under axial load. The calculator on this site works out spring rate, working length and a Wahl-corrected safety factor for this type.
• Extension springs — with hooks or loops, carrying initial tension. The hook is the most highly stressed region of the spring; most failures start there rather than in the body.
• Torsion springs — the body twists and the leg bends. Every pickup and rake group on agricultural machinery belongs to this family.
• Conical springs — coil diameter varies along the length. Chosen for resistance to buckling and for the small solid height when closed.
• Wire form parts — hairpins, R clips, D pins, S hooks, swallowtail and U form parts. More a matter of bending geometry than of spring calculation.

How custom production works

Working without tooling dependency means this in practice: you do not need to commission tooling for a spring that is not on the list. Production can start from any one of three inputs.

The sample route is the most certain — the old spring itself is sent and dimensions are taken from it. The drawing route suits series production and machinery manufacturers. The dimensional route is the quickest: wire diameter, outside diameter, free length and coil count on compression and extension springs; on torsion and form springs, leg length and leg angle as well.

If you cannot measure, a photograph of the old part next to a ruler works for most items. The quote form accepts file attachments, so a photograph, a technical drawing or the drawing sheet produced by the calculator can be attached directly.

Material and coating

Spring steel is chosen according to where the product will work. Spring carbon steel for general machinery springs, stainless where corrosion is a risk, and heat treated spring wire for agricultural items carrying high fatigue loads. The reasoning behind steel selection is set out in a separate article in our technical guide.

Stress relieving after coiling is never skipped. A spring coiled without stress relief loses free length in its first cycles; in the field this is described as "the new spring settled straight away", and it is a quality defect.

On the coating side, galvanised finish is standard, and painted and coloured coatings are also produced. On an agricultural item, coating is not a visual preference: corrosion lowers spring force through loss of cross-section, so an uncoated field spring stops doing its job before it ever breaks.

Questions to ask a spring manufacturer

The most common problem with a spring order is a part that meets the dimensions but not the performance. The questions below exist to prevent that — a supplier without answers may hit the dimension and miss the service life.

• What is the wire diameter range? A narrow range means your requirement may keep landing at the limit. Ours is 0.20–40 mm.
• Is stress relieving carried out after coiling? If not, the spring loses free length in its first season. This is where a price difference is most often hidden.
• Is tooling required? If tooling is required, single parts and small batches are not economic. We have no tooling dependency.
• Do you produce from dimensions, or only from a sample? A supplier that accepts only samples is no help if you have no broken part in hand.
• What coating options are there? Galvanised finish is the minimum on a field spring; an uncoated quote looks cheaper and delivers a shorter life.