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Umbrella metal part

3-Fold Rib (Main / Middle / Tail)

Overview

Made by
Supply chain / partners
Materials
Carbon steel strip (U-channel), Carbon steel wire, Fibreglass (FRP) for the tail rib
Finish options
Black electrophoresis, Zinc / nickel plating, Powder coating

Manufacturing process & quality control points

Qinxi in-houseSupply chain / partnersIn-house or supply chain
  1. 1

    Blanking & straightening

    Supply chain / partners

    Steel strip or wire is cut to length and straightened. Consistent blank length is what keeps the canopy symmetric after assembly.

    Quality control points

    • Blank length · Caliper / limit gauge, per drawing · First article + 1 pc per 2 h
  2. 2

    U-channel roll forming / pressing

    Supply chain / partners

    The rib is pressed into its U-channel profile. The channel gives the rib its bending stiffness; die wear changes the profile and is a common source of weak ribs.

    Quality control points

    • Channel width & depth · Profile gauge / caliper · First article + hourly
    • Rib camber · Template check against master sample · First article + hourly
  3. 3

    Rivet hole punching & end forming

    Supply chain / partners

    Holes for the notch joint, stretcher joint and tip are punched; ends are formed or flattened. Hole position controls the whole frame geometry.

    Quality control points

    • Hole pitch · Go / no-go gauge on hole centres · First article + hourly
    • Burr · Visual, no burr at joint faces · 100%
  4. 4

    Stress relieving (as required)

    Supply chain / partners

    Where specified, formed ribs are stress relieved or tempered to stabilise spring-back. This step is usually outsourced and is why it is tagged either.

    Quality control points

    • Hardness / spring-back · Hardness tester + bend sample check · 1 pc per heat lot
  5. 5

    Surface finishing

    Supply chain / partners

    E-coat, zinc or nickel plating, or powder coating. Plating wears first at the hinge and runner contact points, so coating must be verified together with cycling.

    Quality control points

    • Coating thickness · Thickness gauge per drawing · 5 pcs per batch
    • Corrosion resistance · Neutral salt spray 24-48 h, no red rust (per buyer spec) · Per order
  6. 6

    Tail rib (FRP) forming

    Supply chain / partners

    Tail ribs are commonly fibreglass: pultruded rod is cut, tip-formed and drilled. Fibreglass bends instead of breaking, which is why it is used at the outermost section.

    Quality control points

    • Bend recovery · Bend to specified deflection and release, no break / no permanent set · 5 pcs per batch
    • Tip hole position · Caliper + pin gauge · First article + hourly

Used in

Automatic Open-Close 3-Fold Umbrella

Relevant compliance

Get a quote for 3-Fold Rib (Main / Middle / Tail)

Custom materials, finishes and logos available. Send your drawing or sample.

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