In most situations, a #8 screw calls for a 1/8” straight drill bit. However, the right size of the drill bit deserve to vary relying on the product you’re using, and you’ll need a narrower pilot hole as soon as working through soft materials.

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How to figure Out What dimension Drill bit for #8 Screw

Figuring the end what size drill little for #8 screws will assist you create pilot holes that enable for this fasteners to connect materials securely.

The drill little size shows the diameter that the little bit you’re making use of to create pilot holes for fasteners. The drill little size is one indication the the diameter the the pilot feet you can create, yet the bit size diameter shouldn’t complement the screw diameter precisely to allow the subject to penetrate the material.


There is a wide selection of drill little bit sizes, v some conventional sizes you’ll uncover in most tool kits. If you’re making use of the ISO standard, you’ll describe drill little sizes in millimeters, when the ANSI device uses fractions of inches.

Keep in psychic that many commercial drill bits have a diameter the is actually slightly narrower 보다 the number indicated because the trajectory the the drill little can shift slightly and will typically an outcome in a broader diameter.

In hands-on applications with a center punch and drill, there is a tolerance of .080 customs or 2 mm in most cases. This yongin drops to .020 inches or .5 mm because that applications that require much more precision.

Drill little bit Sizes because that Pre-Drilling Screws and Pilot Holes

Size of ScrewDrill Hole size (Softwood)Drill Hole size (Hardwood)

How Drill little bit Sizing functions for #8 Screws

A good rule of ignorance is to have the diameter the the bit complement the column of the screw without accounting for the protruding threads. This rule enables the threads to cut into the material and act together a reputable fastener with no play.

However, girlfriend shouldn’t apply this rule of ignorance in every situation. Don’t forget come account because that the method different materials behave and how much weight the screw will hold.

It’s also important to think about different species of bits. If you usage a straight drill bit, you’ll develop U-shaped pilot feet with straight walls.

If friend opt for a tapered bit, you’ll drill V-shaped pilot holes. A tapered pilot hole allows the screw come get more contact with the material. It deserve to be more an overwhelming to insert the fastener, yet you’ll finish up through a much more reliable link that have the right to bear much more weight. Typically, you would use a slightly larger drill little bit diameter because that a tapered pilot hole.

The closest enhance you can gain to the diameter the a #8 screw without the object is a 1/8” directly drill bit. This number translates to 0.125” or 3.175 mm.


If you need to produce a tapered pilot hole, opt for a tapered little with a slightly bigger diameter. One 11/64,” 0.171,” or 4.36 mm little bit is your best option.

What does a #8 Screw Mean?

There room 16 typical sizes in the screw sizing system, through numbers varying from 000 come 14. A #8 screw has a diameter the 0.164.” The nearest portion is 5/32.” A #8 screw can have 32, 36, or 40 threads per inch.

These screws are typical fasteners with a wide range of applications. It’s essential to understand what dimension drill little for #8 screw because you’ll come across these fasteners when working on countless different projects.

Keeping part #8 screws comfortable is crucial when functioning on wood building and construction projects. You can use #8 screws to connect wood to wood, affix wood boards to wall studs, certain thicker boards, and also attach fiberboard to a door frame.

It’s likewise a renowned option because that sheet metal fasteners. You’ll often find #8 screws v pan heads and also threads that cover the whole length the the screw for this application.

Do various #8 Screws Need different Drill Bits?

The answer is yes. The first thing you must do is inspect the pointer of her #8 screws and choose the right kind of drill bit. If she using an equipment screws v a level point, you’ll need to use a straight bit.

If you have actually #8 screws through a self-drilling tip, you deserve to use a directly or tapered bit, however a tapered bit will an outcome in a more powerful connection.

The material is one more important consideration. Due to the fact that it’s much easier to gain screw threads v softwoods choose pine, cedar, or spruce, you have to work through a narrow pilot feet to gain a secure connection.

Learn exactly how to usage your drill in our comprehensive guide!


Here room the best drill little bit sizes come use with a straight bit:

7/64” for softwood, or 2.77 mm1/8” for hardwood, or 3.17 mm

If you’re utilizing a tapered bit, here are the recommended sizes:

5/32” because that softwood, or 3.96 mm11/64” for hardwood, or 4.36 mm

For sheet steel fasteners, you’ll need a 0.137” pilot hole if you working with pierced holes. If you’re using drilled holes or clean punched holes, your pilot hole diameter can variety from 0.113 come 0.128.”

For drywall, you’ll need to use wall anchors. Your best bet is to enhance the size of her drill little bit to the diameter that the wall surface anchor you’re using, however you can go over by 1/16,” as long as the fastener i will not ~ bear a many weight.

What size Drill little Do I usage for #8 Screw?

A 1/8” right jobber drill little will carry out a reliable pilot hole because that the 0.164” diameter of a #8 screw. It’s a suitable drill bit size for working v hardwoods favor oak, maple, or walnut and materials with comparable properties.

With softer materials, you’ll need a narrower pilot hole for a much more secure fit.

Get began With #8 Screws

Choosing the right drill bit size is an important when working v #8 screws. This screws are amongst the standard sizes you’ll find on a wide selection of projects, and also you should make sure you have actually the right drill bits for these screws since you’ll more than most likely use them.

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We recommend utilizing a 1/8” right drill little for most applications, however don’t forget to take into consideration the properties of the product you’re using. Girlfriend should likewise consider utilizing a tapered drill little if you need a trusted fastener that will certainly bear much more weight.

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