VEVOR - Paquete de 4 postes para barandilla de cable (36 x 1 x 2 pulgadas), con orificios pretaladrados, de acero inoxidable con soporte horizontal y curvo, color negro, 4JZLGZXHS914UUOI6001V0

It’s 0.31" or 0.41" (NOT 0.031"). The product uses two hole sizes depending on the version: 0.31 in (~8 mm) 0.41 in (~10.4 mm) So the correct value is 0.41", not 0.031" — the smaller number you mentioned is almost certainly a typo/misread decimal point. Thickness: 1.5 mm If this answer does not resolve your issue, please contact us again for assistance.

Ensure your deck has internal blocking (extra wood support) directly beneath the post location, as standard decking boards alone are not thick enough to hold the tension. Using the included concrete sleeves on wood is unsafe, as they will loosen over time and compromise the structural integrity of your railing system. If this answer does not resolve your issue, please contact us again for assistance.

The kit includes expansion bolts specifically designed for concrete or cement surfaces; these will not work effectively for securing the post to a wooden deck. It does not come with lag screws or wood-specific hardware; you will need to purchase these separately at a local hardware store. For a secure wood installation, use stainless steel lag screws or through-bolts that are at least 3 to 4 inches long to ensure they bite deep into the structural joists.