Catalog Searcher
Categories

Fastening Parts

Fastening parts are a general term for screws and anchors used to secure components, and mounting brackets, to a substrate. Listed products include screw-in fixing anchors that are driven into ALC panels (autoclaved lightweight aerated concrete panels) without a pilot hole or with a simple pilot hole, used to fix saddle bands, lighting fixtures, downspout bands, and duct channels, as well as structural screws that fasten structural plywood to load-bearing walls in wood-frame construction. Holding power comes from the thread biting into the substrate. Head shapes include flat (countersunk) and truss heads, selected according to the shape and finish of the fixed item. They are used for building services installation and structural applications in wooden houses.

How to choose Fastening Parts

  1. 1. Select a nominal diameter suited to the substrate and load

    The nominal diameter is the outer diameter of the thread. A larger diameter increases pull-out and shear resistance, but it must pass through the hole in the mounted item. Listed examples are 4 mm, 5 mm and 6 mm; determine the size by matching the hole diameter of the bracket and the weight of the suspended equipment.

  2. 2. Determine the overall length from item thickness plus required embedment

    The overall length L of listed products is 35 to 80 mm. The remaining length after subtracting the thickness of the mounted item (band or bracket) is the embedment depth into the substrate, so for soft substrates such as ALC panels choose a length that secures sufficient embedment. Also confirm that the screw does not pass through the back of the substrate thickness.

  3. 3. Check the thread length engaging the substrate

    The thread length ℓ of listed products is 30 to 55 mm, and this threaded portion provides the holding power. Even with the same overall length, a short threaded section means fewer threads engage the substrate depending on the thickness of the mounted item. Estimate the effective engagement length together with the thickness of the mounted item.

  4. 4. Choose the head shape according to the mounting hole and finish

    Flat heads sink into countersunk holes to give a flush surface. Truss heads have a large, low profile and suit holding down brackets or bands with holes that are not countersunk, using their wide bearing surface. Decide based on the hole shape of the mounted item and whether the head may protrude.

  5. 5. Verify bearing surface and clearance using head diameter and height

    Head diameter D is in the range of 7 to 12 mm and head height H is 2 to 3.5 mm. If the head diameter is not sufficiently larger than the hole in the mounted item, it cannot hold securely, and head height affects interference with surrounding members or covers. For brackets with slotted holes, confirm that the head diameter reliably exceeds the slot width.

  6. 6. Check material and surface treatment for outdoor or humid environments

    Corrosion is a concern for applications outdoors, such as downspout bands. Check the body material (such as stainless steel) and whether anti-corrosion treatment is applied, and watch for galvanic corrosion where the fastener contacts dissimilar metals in the mounting bracket. For structural applications where certified products are specified, as with structural screws, use products that conform to the certified specification.

This guide was written by AI based on the listed products' documents and specification items. Check each manufacturer's documents before adopting.