The sheets of ply have a habit of separating when screws are inserted or even large nails. However, if you get the ball rolling with a little bit of pre-drilling this issue disappears completely.
Coarse thread drywall screws will do the job unless you want something decorative.
If you are building with plywood or MDF, use coarse thread screws. For solid wood, the choice of screws depends on the wood: coarse thread for softwood, fine thread for hardwoods.
Because the wood expands and contracts as a reaction to moisture, nails provide a more flexible fastening job.
The clamping is safest. You can also do a pilot hole all the way through, then the final size buy you will want to drill about half way from one side and the rest from the other. You may have some splintering but is should be minimal. Masking tape on both sides may further reduce splintering.
Screwing into the face of a very soft material like plywood is fine (though even that will splinter at the edges). Always use a drill bit that's smaller than the screw you're using so that the screw has something left over to grab onto. The harder the wood, the more you can guarantee it will crack.
Drill a Pilot/Guide Hole
By far the best thing you can do if you're worried about splitting wood is drilling a pilot hole. By drilling a small hole for the screw, you create a secure passage, reducing the screw's movement and the risk of splitting the wood.
Subfloor. Screw spacing should be 6" o.c. at the boundaries and 12" o.c. in the field, assuming an unblocked diaphragm. For blocked diaphragms increase the numbers of screws by 15%.
The exterior threading results in areas of thin metal that can easily break when exposed to stress or pressure. Nails don't have a threaded shaft, so they aren't as brittle as screws. And in turn, they offer greater tensile strength, making them desirable for construction and carpentry applications.
Environmental Impact: OSB's manufacturing process utilises smaller, fast-growing trees, which could be considered more sustainable. Ease of Installation: Both materials are relatively easy to install, with plywood being slightly more forgiving due to its ability to hold screws along the edges better.
The highest screw withdrawal strength was obtained for sandwich panels made of plywood and medium-density fiberboard (12.51 MPa). Furthermore, the difference between experimental and predicted screw withdrawal resistance changed from 0.20% to 24.86%.
Use wood filler
Crucially, wood filler's extremely easy to use. Most modern fillers come ready-mixed so you don't have to worry about ratios – you simply open the pot and push the filler into the screw hole with a scraper. Wait for the filler to dry, then sand it flush.
Yes, you can use pocket holes with 1/2″ plywood, but you need to use shorter screws, ¾” or 1″, to avoid breaking through the surface.
Coarse-Thread screws are recommended for use with softwoods like cedar, pine, fir, etc. — as well as for sheet goods such as plywood and MDF — that are soft and not very dense. Coarse screws have deep, aggressive threads that bite into those soft fibers to ensure solid holding power.
Their coarse threads grip the wood tightly, ensuring that everything stays stable and reduces the risk of loosening over time. While lag screws can work with other materials like metal and concrete, they shine the most when used with wood.
PAMFast AutoFeed Screws are the preferred choice for interior and exterior subfloor.
Rather than nails, screws are best to use for subfloors — these fasteners are convenient, easy to remove and capable of providing torque that nails lack. Because of their structure, screws can penetrate plywood more easily and improve the connection, whereas nails can weaken the plywood.
Our first recommendation is to pre-drill if you are going to be screwing something into the edge of the plywood. The sheets of ply have a habit of separating when screws are inserted or even large nails. However, if you get the ball rolling with a little bit of pre-drilling this issue disappears completely.
Generally, nails (6d ring or screw shank, or 8d common) should be spaced 6 inches on center along supported panel edges and 12 inches on center on the panels' interior supports, or as specified on the construction drawings. Many manufacturers print a fastener template directly on the panel face.
Fasteners: Recommend 2” #10 exterior wood deck screws either stainless steel or coated with non-staining finish. Slightly recess all fastener heads. Fastener Spacing: Space fasteners 6” (150mm) o.c. along edges and 8: (200mm) o.c. along intermediate supports.
Bury them in counterbores
You then plug the counterbore to either hide it or highlight it, shown below. A counterbore bit drills the pilot hole,countersink, and counterbore in onestep. A set for #6, #8, and #10 screws[Sources] will cover most situations. You can buy plugs or make your own.
For plywood projects, your best bet is aliphatic wood glue. It's easy to use, dries strong, and cleans up with just water. Look for brands like Titebond II or Gorilla Glue Carpenter's Wood Glue. Avoid using superglue – it dries too fast and won't create a strong, lasting bond.
The hole should be as long as the screw so you can drill it in without too much effort.