Screws Buying Guide | Lowe's (2024)

FAQs

What to look for when buying screws? ›

The screws you choose will depend on the task. Things to consider are the thickness, density, and strength of the substrate material, the size and weight of the load they need to hold, and the risk of the material tearing or splitting.

In the Imperial system of units, a number 10 machine screw (0.190 inch major diameter) is bigger than a number 8 machine screw (0.164 inch major diameter).

The screw's length is essential when choosing the right screw size. While thicker materials may require longer fasteners for a firm hold, short screws may be suitable for thinner materials. The general rule is that the screw should enter at least half of the attached material's thickness.

A screw's measurements are usually indicated as diameter x length, so a countersinking wood screw with a 5/32-inch diameter and a 1-1/2-inch length would be labeled as a #8 x 1-1/2-inch countersinking head wood screw.

All screws are listed by diameter but the terms used for different types of screws vary. A 3/8"-16 screw is a machine screw, the "3/8" is the diameter and the "16" is the number of threads per inch. This screw will thread into a nut or threaded hole.

The "No 10" does not have a numerical relation to the screw size, other than the larger the number the larger the screw is. A No10 screw is approx 5mm diameter or 3/16" if you're doing imperial.

A good all-around choice is #10 decking screws—generally in 2 1/2- to 3 1/2-inch lengths. Decking screws are sharp, tapered, self-sinking, and coated for corrosion resistance. With a cordless drill/driver, you can drive them about as fast as nails.

Common choices for fastening 2x4s together include wood screws, deck screws, and drywall screws. The most typical screw sizes for this purpose are: #8 Screws: These are 2½ inches to 3 inches in length and are commonly used for general construction and framing with 2x4s. They provide a strong and secure connection.

To measure the diameter of screws and bolts, you measure the distance from the outer thread on one side to the outer thread on the other side. This is called the major diameter and will usually be the proper size of the bolt.

What is the most common screw size? ›

The most common size of wood screw is #8 (approximately 5/32 inch in diameter), but as we've said before the best size of screw for you will depend on the project or task you're pursuing.

According to the Bolt Depot, the strongest is a grade 8 “Medium carbon alloy steel, quenched and tempered” with a minimum tensile strength of 150,000 psi, proof load of 120,000 psi , and a minimum yield strength of 130,000 psi. 1/4 to 1 1/2 inches long.

The most common grading system used for bolts in the U.S. is the SAE system, but you can find metric grading systems as well. There are several grades of bolts but the three common grades for SAE are 2, 5 and 8. The common class (grades) for metric are 5.8, 8.8, 10.9 and 12.9. Each grade has a specific bolt strength.

The #8 gauge screw has a major diameter of 0.17" and 8 TPI. The screw is 1-1/4" long, a measurement taken from the bottom of the head to the point. If you're shopping for collated screws and need help, contact Customer Service for assistance. Shop Collated Screws.

A lag screw is the strongest in the family of wood screws. It is a sturdy and durable fastener often designed with an externally driven hex drive or square head. Lag screws feature a tapered point and coarse threads and are typically tougher and much heavier than conventional wood screws.