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Adjusting & fastening

Cap Back Closure Set (Slider + Oval / Round Eyelets + D-Ring)

The metal kit that turns the open back of a cap into an adjustable closure: a square sliding adjuster tucks and locks the strap, oval and round eyelets reinforce the holes the strap passes through, and a D-ring anchors the free end. Kit sizes are a slider around 18 x 21 mm, an oval eyelet around 25 x 12 mm, a flat oval eyelet around 26 x 13 mm and a round eyelet around 9 mm outside diameter.

Overview

Made by
Supply chain / partners
Materials
Brass, Iron / low-carbon steel, Stainless steel, Zinc alloy (die-cast slider version)
Finish options
Nickel, Nickel-free plating, Antique brass, Gunmetal, Black nickel, Matte brushed, Lacquer sealed
Customization
Logo on the slider face, Plating matched to the eyelet and front-panel trim, Set composition (slider only, or slider + eyelets + D-ring), Strap width and eyelet barrel length to the cap maker's strap, Nickel-free specification for EU skin contact

Applications

  • Baseball capsStandard strapback: slider on the inner band, eyelets on the outer strap end
  • Work capsHeavier strap material; eyelet barrel length must match the thicker strap
  • Bucket hatsUsed mainly as a size adjuster inside the sweatband
  • BackpacksThe same slider plus eyelet combination is widely used to repair or finish backpack straps

Selection tips

  • Decide stamped or die-cast at the enquiry stage. Stamped brass/steel kits are cheaper and thinner; zinc die-cast sliders take a logo and more shape but need a tool.
  • Eyelet barrel length must match the strap thickness: too short and it will not roll over, too long and the flange stands proud and scratches.
  • Ferrous parts can trigger garment needle detectors. For markets where finished garments are 100% needle-detected, specify brass or a non-magnetic stainless grade and confirm on the buyer's detector.
  • Nickel release applies to anything in prolonged skin contact, and a sweatband is exactly that - ask for nickel-free plating on EU orders.
  • Salt spray hours alone are not a specification; pair the duration (commonly 24-48 h NSS, ISO 9227) with a coating thickness and an acceptance rating.
  • Order the eyelet setting tool matched to the eyelet: a mismatched die crushes the barrel instead of rolling it, which is the most common cause of loose eyelets.

Manufacturing process & quality control points

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

    Route decision: die-cast vs stamped

    Supply chain / partners

    Two routes exist for the same kit. A zinc alloy die-cast slider is made on Qinxi's own die-casting line (in-house); the sheet-metal slider and the eyelets are progressive-die stamped parts and Qinxi has no stamping or cold-heading line, so those come from the supply chain.

    Quality control points

    • Route confirmed against material and order quantity · Engineering review of the enquiry · Each new tool or project
  2. 2

    Stamping of slider and eyelets

    Supply chain / partners

    Coil stock is blanked, drawn and formed in a progressive die; the eyelet barrel must be formed so that it rolls over cleanly instead of splitting when set.

    Quality control points

    • Barrel and flange dimension · Caliper and go/no-go gauge · Per lot, AQL 2.5 (ISO 2859-1 general level II)
    • Cracking after setting · Trial setting on the production strap · One sample set per batch
  3. 3

    Deburring, polishing and plating

    Supply chain / partners

    Parts are tumble deburred, polished and plated. Burrs matter more than they look: on a cap sweatband a sharp edge scratches the wearer, and burrs on garment trims are also a needle-breakage risk in automated sewing.

    Quality control points

    • Sharp edge / burr · Gloved touch check plus 10x loupe · Per lot, AQL 2.5 (ISO 2859-1 general level II)
    • Coating thickness · XRF coating thickness gauge (ISO 3497 / ASTM B568) · One set per plating colour per batch
    • Corrosion resistance · Neutral salt spray, 5% NaCl, 35 C (ISO 9227 / GB/T 10125) · One sample set per batch
  4. 4

    Function test on the real strap

    Supply chain / partners

    The slider is fitted to the production strap and pulled: it must hold under normal wearing tension and still release by hand. Holding behaviour depends on the strap material, not only on the metal part.

    Quality control points

    • Slip resistance on the production strap · Fit test with the actual webbing to be sewn · One sample set per batch
  5. 5

    Kit assembly and packing

    Supply chain / partners

    Slider, eyelets and D-ring are counted into sets and packed so plating surfaces do not scuff each other. Set assembly is handled by the supply chain.

    Quality control points

    • Set count and composition · Weigh-count or 100% count check · Per lot, AQL 2.5 (ISO 2859-1 general level II)
    • Eyelet pull-through on the strap · Universal tensile machine, 50 mm/min, record peak and failure mode · One sample set per batch

Relevant compliance

Get a quote for cap back closure set (slider + oval / round eyelets + d-ring)

Custom shapes, finishes and logos. Email us your artwork or sample photos.

Request a quote