What size is a #10 screw?
US Machine Screw Diameters
Drill bit sizes for pre-drilling (most commonly used sizes in bold)
|Screw Size||Pilot hole size for hardwoods*||Pilot hole size for softwood**|
- Use a bit 1/64” smaller than the target hole size for softwoods. Use a bit exactly the same size as the hole when working on other materials. If you're not sure which to select, choose a drill bit 1/64” larger than the hole you wish to create. This will account for variables such a wood density and screw type.
- Cobalt (HSCO) is considered an upgrade from HSS because it includes 5-8% Cobalt blended into the base material. This is a great option for drilling into harder steel as well as stainless steel grades. Carbide (Carb) is the hardest and most brittle of the drill bit materials.
- Wood Screw Diameters
Size Major Thread Diameter* Decimal Nearest Fractional Measurement #8 .164" 5/32" #9 .177" 11/64" #10 .190" 3/16"
Wood Screw Pilot Hole Sizes
|Screw Size||Hard Wood|
|Tapered Bit||Straight Bit|
- Drill the tap hole: The size of the drill bit to be used is dependent on the type of spile you are using. Most spiles require either a 7/16 or 5/16 bit. Drill a hole 2 to 2 ½ inches deep.
- Your normal wood screws are not structural. While undoubtedly considerably stronger than normal screws, this leads me to still question their shear resistance. In the end: nails, hex bolts, and lag bolts are still better in most applications. Structural screws are just easier than bolting and cooler than nailing.
- Difference Between Nails and Screws. Since a screw has threads, you can not use a hammer, you need a screwdriver or some tool that turns the screw into the material. Hence that is why on the top of a nail, the head is flat, while the screw has a dimple for a philips, flat head or another type of tool to do the turning.
Your pilot-hole drill-bit size will depend on the size of your sheet-metal screw. A size-4 screw should have a pilot-hole drill size of 3/32 inches; size 6, 7/64 inches; size 8, 1/8 inches; size 10, 9/64 inches; size 12, 5/32 inches; size 14-1/4 inches, 3/16 inches; and 5/16 inches, 1/4 inches.
- Wood Screw Pilot Hole Sizes
Screw Size Hard Wood Soft Wood Tapered Bit Tapered Bit #7 5/32" 9/64" #8 11/64" 5/32" #9 3/16" 11/64"
- Wood screw diameter can be measured either as a shank diameter or a root diameter. The measurement is then cross referenced to a size number known as a wire gauge size. Thread diameter is used when measuring sheet metal screws. The measurement is then cross referenced to a size number known as a wire gauge size.
- The sharp-tipped screws are designed for drilling their own hole into softer materials such as wood and plastic so they don't need a pilot hole. For thicker metal, it may require more than one screw to drill through the surface. To save time and labor, you can use self-drilling self-tapping screws to drill into metal.
Updated: 3rd December 2019