What Size of Drill Bit Do I Need For a #6 Screw?

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So you’ve got yourself a wood drill and some #6 screws, and you can’t wait to try it out. The problem now is finding the right size of drill bit for #6 screws. There’s a lot to choose from, and even the most experienced woodworker can get lost. 

But fret not, our engineers have compiled everything you need to know about drill bits for #6 screw.

What Drill Bit Size Corresponds to a #6 Screw?

For a #6 screw, the recommended pilot hole sizes are 5/64″ for softwoods and 3/32″ for hardwoods. 

If you refer to the table below, you will notice that hardwoods generally require larger pilot holes. This is for a good reason: hardwoods are denser and may crack when a screw is driven in if the hole is made too small. 

#6 screws

In contrast, softwoods have more give; their fibers can compress and decompress a bit more. Hence, they require a smaller pilot hole that will create a tighter fit for the #6 screw.

Screw SizeDrill Hole Sizes

The diameter of tapered bits gets increasingly smaller as you get to the tip, as opposed to straight bits that maintain a uniform diameter all throughout. 

different screw sizes

The following table includes hole sizes made with tapered bits and straight bits. For softwood, #6 screws would need a 1/8″ tapered bit or a 3/32″ straight bit. For hardwood, #6 screws would need a 9/64″ tapered bit or a 7/64″ straight bit. 

Screw Size

Tapered BitStraight BitTapered BitStraight Bit

How to Properly Utilize a #6 Screw

#6 screws are mostly used in fine woodworks like boards, or wooden box projects. These need smaller holes, and thus, a smaller size screw like #6 is preferable, if not necessary.

You need to determine the type of wood you are using for your project. Is it hardwood or softwood? This will dictate the size of drill bit you would need. Refer to the table above for the pilot hole sizes and the drill bit sizes you would need to fasten a #6 screw properly. 

#6 screw on wooden surface

When you have chosen your drill bit, you will need a drill. Cordless drills are fine for smaller projects involving #6 screws, but for tougher wood, you might need a corded drill for more torque. 

Most drills nowadays can double as a screwdriver with screwdriver attachments, but if you made proper pilot holes, a regular screwdriver is enough for a #6 screw. 

Considerations to Know for #6 Screws

#6 screws are commonly used for boards and plywood. For thicker materials, you might want to consider using  #8 to #12 screws. 

drilling on wood

Take into consideration the type of wood as well. For softwoods, you will usually create smaller pilot holes, as opposed to slightly larger ones on hardwoods. 

What to Do Before You Use #6 Screws

Screws act as a wedge when driven into materials like wood. Without proper preparation, the screw can split the wood, especially hardwood. 

This is why you need to drill pilot holes. A pilot hole is a hole you drill in a construction material (in our case, wood); you can drive a screw in easily, safely, and securely. Think of it as a primer for screws. Measure the pieces of wood you will be joining with the screw so you can get screws of the proper length.


Is M6 the same as #6?

No, M6 is not the same as #6. The ‘M’ in M6 means metric. All measurements of screws in this series–M0, M1, M2, and so on–use the metric system [1]

#6 screws, or Number 6 screws along with the other screw sizes on the tables above, use the Unified Thread Standard commonly used in the US and Canada. 

What does a #6 screw mean?

A #6 screw means that it’s the sixth thread size in the Unified Thread Standard. It has a certain diameter along with others in the standards, and for simplicity, is just referred to as such.


As the saying goes, “the right tools, for the right job.” You need the proper drill bit and the proper hole for the screw you will use. In this article, we listed the size of drill bits you will need for #6 screws and the preparations and considerations you need to know. 

Robert Johnson is a woodworker who takes joy in sharing his passion for creating to the rest of the world. His brainchild, Sawinery, allowed him to do so as well as connect with other craftsmen. He has since built an enviable workshop for himself and an equally impressive online accomplishment: an extensive resource site serving old timers and novices alike.
Robert Johnson
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