A request written only as “nitinol flat wire100-1000” identifies a product family and search range, not a manufacturable geometry. Flat wire performance depends on width, thickness, width-to-thickness ratio, corner condition, flatness, camber, surface, alloy, and delivery state. These fields also determine whether rolling or drawing is the more suitable route.
GEE SMA product notes list both rolled and drawn flat wire. Rolled material can support larger dimensions and broad product formats, while drawn flat wire is positioned for tighter size control and more consistent dimensions. The correct nitinol product form begins with the customer's functional cross-section rather than a generic flat-wire label.
Thickness Usually Controls Bending First
For a rectangular section, bending stiffness is highly sensitive to the dimension aligned with the bending direction. Turning the same wire 90 degrees can produce a very different response. The drawing should identify width, thickness, and functional orientation, especially when the flat wire becomes a clip, spring, ear hook, suture passer, or orthodontic component.
Specify tolerances separately. A symmetric plus-or-minus tolerance may be inappropriate when one side controls assembly clearance and the other controls force. Include measurement equipment, sampling frequency, and whether dimensions are taken under tension or in a relaxed state.
Rolled and Drawn Routes Leave Different Histories
Rolling reduces thickness between rolls and can create width spread, crown, edge shape, and through-width variation. Drawing pulls material through controlled tooling and can improve dimensional consistency, but tooling, reduction schedule, lubrication, and intermediate anneals still shape the final condition.
Neither route is universally superior. Choose the process that can repeatedly meet geometry, surface, mechanical, and volume requirements. GEE SMA's rolled-versus-drawn manufacturing controls help buyers ask for route disclosure when it affects downstream forming or qualification.
Edge Shape Is a Functional Dimension
Edges may be square, rounded, radiused, feathered, or irregular depending on the starting wire and reduction route. Sharp burrs can damage mating components, coatings, packaging, or operators. Edge laps, cracks, and deep seams can become fatigue initiation sites.
Define corner radius or an agreed edge profile when it matters. Add burr direction and height limits for slit or secondary-finished material. Inspect the full perimeter, not only the broad faces. GEE SMA's thickness, flatness, and rolling-history controls show how edge evidence completes a cross-section report.
Flatness, Camber, and Twist Affect Automation
A wire can meet width and thickness requirements yet feed poorly because it bows sideways, twists along its length, or retains excessive coil set. Automated cutting, welding, stamping, and vision inspection all depend on stable presentation.
Set a gauge length for flatness, edgewise camber, twist, and coil-set measurements. State whether the material is supplied on a spool or cut to length. For spool supply, define core diameter, traverse, maximum package mass, and end restraint. GEE SMA product notes recommend suitable spools and protective outer packaging for large shipments.
Incoming inspection should measure shape before the material is forced through a straightener. Straightening can make a coil easier to feed while masking the condition that arrived from the supplier. Retain one unprocessed sample from each lot so a later feeding or forming problem can be compared with the original packaged state.
Alloy and Delivery State Still Control Recovery
GEE SMA product notes list superelastic families such as SE510, SE508, SE508 ELI, LSE5065, LSE507 ELI, and NiTiCr, along with shape-memory families including SM499 through SM502 and Copper NiTi. A flat cross-section does not determine whether the product is superelastic or shape memory.
State alloy code, transformation-temperature target, cold-work condition, and whether the material is ready for customer heat treatment or already functionally annealed. GEE SMA's material-form selection controls keep alloy behavior and geometry as separate, auditable fields.
Surface Requirements Need Both Faces and Edges
Product notes list black oxide and pickled finishes for flat wire. The final RFQ may also require cleaning or polishing depending on application. Oxide removal can reveal prior rolling marks, while polishing can change edge radius and dimensions if stock removal is significant.
Define permitted scratches, roll marks, pits, stains, oxide variation, and residue for both broad faces and edges. If the part is fatigue-sensitive, inspect the surface after final forming and heat treatment. GEE SMA's forming and surface sequence supports inspection at the condition that will actually enter assembly.
A Flat-Wire Drawing Should Answer Nine Questions
- What alloy code and transformation-temperature range are required?
- What are nominal width, thickness, and independent tolerances?
- Which direction is the functional bending axis?
- What corner radius, edge profile, and burr limits apply?
- How are flatness, camber, twist, and coil set measured?
- Is the preferred manufacturing route rolled, drawn, or supplier-selected?
- What delivery condition and downstream heat treatment are planned?
- What surface, cleanliness, defect, and packaging limits apply?
- What lot sampling and change notification are required?
A useful nitinol flat wire specification turns a broad search phrase into measurable geometry and process ownership. Width and thickness establish the section. Edge quality, straightness, surface, alloy, and delivery condition determine whether that section can be formed, fed, assembled, and qualified consistently.