Stainless Spring Wire 302 - Marked Splices, Stable Feed
302 stainless spring wire
,marked splice spring wire
,stable feed stainless wire
302 Stainless Spring Wire with Marked Splices for Planned Coil Changes
Product Introduction
Long spring wire coils contain at least one splice, because drawing and annealing equipment works in finite lengths. What matters on a coiler is not that a splice exists, but whether the operator knows where it is before the wire reaches the feed rolls.
Every splice in this wire is a butt weld, annealed at the joint, dressed flush, and marked with a tag and paint mark placed ahead of the joint on the coil. The coil tag records the distance from the outer end so the coiler can plan a stop instead of losing a spring length.
Available in diameters from 0.15 mm to 12 mm, grade 302 and 304, bright or soap coated finish.
Product Specifications
| Parameter | Specification |
|---|---|
| Grade | 302, 304, 316 |
| Diameter Range | 0.15–12 mm |
| Diameter Tolerance | ±0.02 mm up to 2.0 mm; ±0.03 mm above 2.0 mm |
| Tensile Strength | 1450–1850 MPa, grade and diameter dependent |
| Splice Type | Butt weld, joint annealed and dressed flush |
| Joint Strength | ≥ 85% of parent wire tensile strength |
| Splice Count | ≤ 2 per coil, customer specified |
| Splice Marking | Paint mark and tag about 1 m ahead of the joint |
| Surface | Bright, soap coated option |
| Coil Weight | 100–500 kg |
| Reference Standard | ASTM A313, EN 10270-3, JIS G4314 |
Why Splices Exist in Long Coils
Drawing and Annealing Length Limits
Wire is drawn and annealed in finite lengths before coiling. To deliver one continuous coil of several hundred kilograms the ends are joined and the run continues. A coil with no splice would mean a coil weight the handling and annealing equipment cannot take.
What a Splice Does to a Coiler
A joint is slightly different from parent wire: diameter can sit a few microns above nominal, and the weld zone may be harder or softer depending on the post-weld treatment. On a coiler this shows up as a feed hiccup, or a step change in formed height for the few parts made from the joint.
How Splices Are Marked and Recorded
Physical Marking
Each splice carries a paint mark and a tag about one metre ahead of the joint, on the pay-off side you specify.
Position Record on the Coil Tag
The coil tag states the number of splices and the approximate distance from the outer end to each one, so the operator can set a stopping point before the joint arrives.
Splice Count Limit
Coils are supplied with a stated maximum, normally one or two splices per coil. Customers running unattended production usually specify one.
Joint Quality Requirements
Joint Strength
The welded joint is tensile tested and must reach at least 85% of parent wire strength. A brittle joint that fails at the die costs more than a marked one that gets cut out.
Diameter and Alignment at the Joint
The joint is dressed flush and checked for diameter over the weld zone. A raised burr marks the guide rollers, and from then on every metre of wire that follows carries the same mark.
Post-Weld Anneal
The weld zone is annealed locally so the joint forms without cracking when it passes through the coiler, instead of acting as a hard spot in the tooling.
Applications
Compression and Torsion Springs
Coiling lines that run large coils to reduce changeover, where a known splice position is part of the production plan.
Wire Forms and Snap Rings
Forming operations where a diameter step at the joint would show up as a dimensional reject rather than a cosmetic one.
Automatic Coiling Lines
Machines with a splice detector or a programmed stop, which need the tag position and the coil tag record to match.
Product Advantages
- Every splice is marked ahead of the joint, so the coiler stops on plan instead of on a broken part.
- Splice position and count are written on the coil tag, giving a traceable record for each coil shipped.
- Joints are annealed and dressed flush, so the weld zone does not act as a hard spot in the tooling.
- Splice count can be limited to one per coil for unattended production lines.
- Tensile strength range and diameter tolerance are stated per lot, so the coil build matches the spring design.
Quality Control
Each lot is checked for chemical composition, tensile strength, diameter and ovality, and surface condition. Splices are tensile tested, inspected for burr and diameter step, and counted against the order limit. The coil tag, inspection sheet and mill test certificate 3.1 travel with the shipment.
Selection and Ordering Notes
- State grade, diameter and tensile range required for the spring design.
- Give the maximum splice count per coil you accept, and whether a splice detector is fitted on the line.
- Confirm which end is the pay-off end, so the mark is placed on the correct side of the coil.
- State coil weight and inner diameter to match your pay-off equipment.
- For lines that cannot cut out a joint, ask for shorter coils with a single splice or none.
Tell us your coiler type, coil weight and the maximum splice count you accept, and we will plan the coil build and the marking accordingly.
