Flat-Back Triangular Wire

Flat-back triangular wire is the standard V-profile with one modification: instead of a fully pointed back, one face is flattened into a narrow land, typically 0.5–1.5 mm wide. The apex still points outward and still forms the slot; the flat face on the back is there for one reason — it gives the weld bead, the clamp or the support rib a flat surface to land on.

Why the flat face exists

Standard triangular wire is clamped or looped into the screen frame. That works when the screen is built as a tensioned assembly. But a large share of wedge wire screens are welded: each profile is fusion-welded to the support rods at every intersection. A knife edge meets a round support rod at a single tangent line — the arc is unstable, burn-through is common, and the weld quality varies with the operator.

A flat back changes the joint geometry. The weld lands on a defined land, penetration is repeatable, and the profile sits square against the rod without rolling. The result is a screen that holds slot accuracy after welding instead of drifting as the welds shrink.

Where it is the right choice

• Fully welded screens. Oil well screens, water well screens and laterals where every wrap is welded to the support.
• Sieve bends and static screens. Profiles seat flat into machined grooves in the frame.
• Repair segments. A patch welded into an existing screen — the flat face forgives the hand-positioning that repair welding involves.
• Filter elements with bonded backing. Adhesive and brazing both need a land, not an edge.

If your screen is built by looping and tension rather than welding, standard pointed-back triangular wire is lighter and cheaper — see the standard sizes on the triangular wire list.

How the flat face is specified

Three numbers, then the slot: profile width, height, and flat-face width. The face width is the trade-off dial — wider lands weld more easily but reduce the effective V depth slightly; a narrow land keeps the slot geometry close to a standard profile. For machine welding, 1.0 mm is a common starting point; for hand welding and repair work, 1.2–1.5 mm forgives more.

The slot itself is formed by the apex angle, exactly as with standard V-wire, so slot sizing carries over. The 3×5 triangular wire and 1.8×2.7 pages show how slot and profile dimensions relate.

Specifications

Slot geometry, K-profiles and the screen-specific naming are covered in V, K or trapezoid; the screen assemblies these profiles build are under wedge wire. Send the slot width and whether the screen is welded or looped — the flat-face width follows from that one answer.