Wood Screw Size Chart

Long before wood screws were a thing, carpenters were using adhesives, nails, and wood joints to fuse to or more segments. Each technique had its disadvantages and advantages. However, the inception of this new wood fastener introduced a new way of fastening and mounting.

Summary

Wood screw sizes come in many options, and the best way to find the right wood screw size is with the charts below. Choosing the wrong material, as well as mixing the metric and imperial measurement systems are serious mistakes to avoid making with wood screws.

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Wood screws work with hardwood, chipboard, MDF, and softwood. Several types are available in the market, which have different features. Most have safety features, such as the following:

  • Avoid wood splitting through shanks
  • Effective driving through twin threads
  • Sharp tips will no longer need you to pre-drill

You can purchase these items in different head shapes and drive types. Each one is best for a specific application. Manufacturers initially use steel or bras to produce these items. The shaft has an increasing thickness from the tip to the head.

These fasteners have several thicknesses and lengths. We are covering everything you need about wood screw size charts, types, and some practical applications. 

Wood screw size charts

The tables below shows the typical measurements. Slight variations are possible depending on the type. 

Here are the wood screw size charts you need


“A” Flat Head“A” Flat Head“A” Pan Head“A” Pan Head“A” Pan Head“A” Round Washer Head“A” Round Washer Head“A” Round Washer Head“B” Body Dia“B” Body Dia“C” Thread Dia“C” Thread Dia
SizeMinMaxMinMaxT maxMinMaxT maxMinMaxMinMax
40.1950.2250.2050.2190.086N/AN/AN/A0.0840.0950.1050.116
60.2440.2790.2560.270.103N/AN/AN/A0.1070.1180.1310.142
80.2920.3320.3060.3220.120.3520.3760.110.1250.1360.1570.168
100.340.3850.3570.3730.1370.4110.4430.1250.1460.1570.1830.194
120.3890.4380.4070.4250.153N/AN/AN/A0.1650.1760.2090.22
140.4520.5070.4730.4920.175N/AN/AN/A0.190.2010.2350.246

 

Gauge

Screw GaugeHead diameter (mm)Shank diameter (mm)
00002.741.37
0002.891.44
003.041.52
03.201.60
13.351.67
24.062.03
34.772.38
45.482.74
56.193.09
66.603.30
77.623.81
88.334.16
99.044.52
109.754.87
1110.465.23
1211.165.58
1311.885.94
1412.586.29
1513.306.65
1614.027.01
1714.737.36
1815.447.72
1916.148.07
2016.868.43
2117.568.78
2218.289.14
2318.989.49
2419.719.85
2621.3310.56
2822.5511.27
3023.9711.98
3225.4012.70

Length

Length (Inches)Length (mm)
¼”6.4mm
⅜”9.5mm
½”12.8mm
⅝”15.9mm
¾”19.1mm
⅞”22.2mm
1″25.4mm
1 ¼”31.8mm
1 ½”38.1mm
1 ¾”44.5mm
2″50.8mm
2 ¼”57.2mm
2 ½”63.5mm
2 ¾”69.9mm
3″76.2mm
3 ¼”82.6mm
3 ½”88.9mm
4″101.6mm
4 ½”114.3mm
5″127.0mm
6″152.4mm
wood screws next to a ruler

Sizing explained

If you search for sizing, you will see different lengths, gauges, and threads, confusing several people. Take extra care while choosing because one wrong choice may ruin the entire application. Here are three parts worth keeping in mind.

The main measurements fall under three categories – threads per inch (TPI), length, and gauge. These are the measurements you will often encounter when shopping for these items.

Premium wood screws of various types

Gauge

The gauge is the first number, referring to the thread diameter. Others also refer to it as major diameter. The size labels #0 to #14 have a major diameter of less than 0.25 inches, while greater than #14 are in fractions of an inch.

Each gauge size has an equivalent decimal value. For example, a #1 gauge is 0.073 inches. The size has an incremental value of 0.013 inches per gauge.

Aside from the major diameter, we also have the minor. It refers to the width measurement below the threaded part. We call the unthreaded portion the shank diameter.

Length

The length of the shaft is the next important measurement. The part of it that drives through a surface is the shaft length. You measure from the tip to the top of the head for types that can drive beneath the surface. These countersinking types include the bugle-head, trim-head, and flat-head.

You measure from the head’s bottom to the tip for types you cannot drive beneath the surface. Some examples of this non-countersinking are round, hex, button, pan, and truss. One exception to it is the oval head, which classifies as partial-countersinking. 

Threads per Inch (TPI)

The TPI refers to the thread count within a one-inch section. It occasionally follows the gauge with a hyphen. A label that says #8-10 means a #8 gauge and ten threads per inch. 

Wood screws

Length

Several lengths are available in the market. The largest size most manufacturers produce is size 32. It has a shank diameter of 0.5 inches and a head diameter of one inch. On the other hand, the small size most manufacturers have is size 0000, with a shank diameter of 0.054 inches and a head diameter of 0.108 inches.

Generally, a head reduction of 0.0028 inches and a shank reduction of 0.0014 inches happens until it reaches size one. The diameter reduction is 0.006 inches and 0.003 inches after it passes this point, respectively.

Types

Not all wood screws are a one-type-fits-all. Each variety has a recommended application. For example, a flat head is best for cabinetry. However, a hex head is best for roofing and flooring. The following are the common wood screws in the market.

wood screw seen from above

Hex Head

As the name suggests, there is a hexagonal shape on the head of this variety. It helps you drill faster while reducing the chances of stripping. The most common applications are on bearing structures, roofs, and floors.

We recommend the following products for this type.

LuKaiSen Self-Tapping Hex Head

Pros

  • Large variety of screws – 17 different sizes.
  • Exquisite storage box.

Cons

  • They keep breaking during drilling.
LuKaiSen Self-Tapping Hex Head
17 different sizes to choose from.

EASTLO Hexagon Head

Pros

  • Great addition to any garage or workshop.
  • They do not break under pressure.

Cons

  • Poor customer service, the company did not answer our questions.
EASTLO Hexagon Head
You need these in your garage.

Heavy Duty Hex Head

10-inch heavy duty wood screws

These screws are intended to support loads heavier than those carried by hex-head structural screws. Their washer heads are wider than the others. When considerable tension is present, they first prevent the head from sinking into the material. Secondly, the wider head improves grip on the surface. These screws have a diameter ranging from 66 to 87 millimeters.

We recommend the following heavy-duty products.

VIGRUE Heavy Duty Kit

Pros

  • Affordable price and exceptional value.
  • Large variety of screws.

Cons

  • The bolts are not coated well.
VIRGUE Heavy Duty Kit
Premium stainless steel coated with black oxide.

Jake Sales Heavy Duty Fastening Kit

Pros

  • Superior quality.
  • They can support heavier loads.

Cons

  • Some screws were missing from the package.
Jake Sales Heavy Duty Fastening Kit
Perfect for jobs with heavy loads.

Stainless Steel Hex Head

The stainless steel type is corrosion-resistant, allowing you to use it in places high in moisture. A hex head prevents it from stripping out during insertion or removal.

The following items are our recommendations.

SG TZH Sheet Stainless Steel

Pros

  • We fastened 2 pieces of wood with this screw.
  • Less prone to rust and corrosion.

Cons

  • We had to wait a long time for the package to be delivered.
SG TZH Sheet Stainless Steel
No more worrying about rust and corrosion with these ones.

Mellewell Stainless Steel Screw

Pros

  • Great for thin material.
  • Will hold well in wet environments.

Cons

  • Not as strong as other models.
Mellewell Stainless Steel Screw
These are simple but they always get the job done.

Flat Head

The difference between the standard hexagonal and flat-head varieties is the absence of angled edges, reducing screw splinters. The best application is finishing wood cabinetry. These have a tighter thread, allowing more grip and higher resistance.

The following are our recommendations.

BCP Fasteners Flat Head for Wood

Pros

  • BCP Fasteners is a well-known company.
  • We appreciate the black phosphate coating.

Cons

  • They have a very sharp point and you can get hurt easily.
Sale
BCP Fasteners Modified Truss Head
Produced by a trusted brand with many positive reviews.

Mr. Pen Flat Head Assortment Set

Pros

  • Easy to store thanks to the package included.
  • Great value for the money.

Cons

  • Some screws were missing from the package.
Sale
Mr. Pen Flat Head Assortment Set
Screws made of halvanized iron with a good holding power.

Standard Wood

We use the standard type to fuse wood pieces. The head is smooth, and the shank has threads. The flat type provides a finish after driving into the wood. You will find it cheaper and available in several varieties.

We recommend the following products for this type.

JERLITU Self-Tapping Standard Kit

Pros

  • We love how precise these screws are with their high-precision cutting technology.

Cons

  • They are fragile and you have to handle them with care.
JERLITU Self-Tapping Standard Kit
With 8 different kinds of screws, there are plenty to choose from.

BCP Fasteners Modified Truss Head

Pros

  • Heads will not break with more torque.
  • Strong and durable, the heads do not shear off.

Cons

  • You can get hurt by the splinters. We recommend wearing gloves.
Sale
BCP Fasteners Modified Truss Head
You need these in your garage before you start working.

Pocket

The pocket is famous for its self-tapping ability. The wide head attaches to the flat shoulder.

We recommend using this with pocket holes. Please refrain from using a standard type because it will split the wood. The square drives you will find the help you place it easily.

We recommend the following products for your pocket screw needs.

Massca Pocket Assortment Kit

Pros

  • We love the case that contains the screws.
  • Large variety of screws for multiple purposes.

Cons

  • The heads strip out easily.
Massca Pocket Assortment Kit
This one comes with a box ideal for organizing your screws.

LIONMAX Self-Tapping Exterior Screws

Pros

  • Great for both outdoor and indoor uses.
  • The tip is very sharp.

Cons

  • Not ideal for bigger projects.
LIONMAX Self-Tapping Exterior Screws
300 sharp screws for your projects.

Deck

The deck’s best application is outdoors. Manufacturers use copper or steel, allowing resistance from corrosion. The shanks on these have deep threads and sharp tips, making it easy to drive through the surface of the boards.

We can use the deck type on hardwood or softwood applications. They are most useful for people living in coastal areas, where weather conditions are more unpredictable and harsher. This type can withstand all weather conditions while providing a firm and secure bond.

We recommend the following deck types.

Juusmart Stainless Steel Deck Kit

Pros

  • Made of strong marine-grade stainless steel.
  • Excellent for both outdoor and indoor applications.

Cons

  • The package took a long time to arrive.
Juusmart Stainless Steel Deck Kit
Durability ensured by marine-grade stainless steel.

Deck Plus Wood Screws

Pros

  • Good customer support – the company answered all of our questions.
  • They are ideal for outdoor projects.

Cons

  • Heads strip out easily.
Sale
Deck Plus Wood Screws
Best screws for outdoor use.

Drywall

Drywall is the cheapest among all the types, which most people use for woodwork. The thread runs through the entire length and has a thin shank. However, they are not very durable. We do not recommend using them in hardwood.

The following are our recommendations.

Prime-Line Drywall

Pros

  • Good deal, cheaper than those sold at retail stores.
  • Perfect for any kind of job.

Cons

  • The screws are covered in black oil.
Prime-Line Drywall
Sold by a trusted company with more than 40 years of activity.

Rustark Coarse Thread Drywall

Pros

  • Large variety of screws.
  • We like the versatility of this product.

Cons

  • Packaging is haphazardous.
Rustark Coarse Thread Drywall
Multi-purpose screws that are easy to install.

Selecting the suitable size is equally important as choosing the right length. The thickness must also fit the width of the material. Moreover, we recommend ensuring it can support the load.

By Head Drive Type

The main head types are as follows.

  • Slot-head – This is the most common variety among all the head types. You can use a flat-head screwdriver to turn the head through the material. 
  • Robertson or Square Drive – The Robertson has a few advantages over the Phillips. The square drive features a square head, reducing the chances of slippage. You will usually find it in pocket screws.
  • Phillips – The Phillips is more functional than the slot-head variety. It works well on different wooden materials, allowing you to insert it with minimal risks. You may encounter slipping when driving it through the final section. 
  • Starhead – There has been an increase in popularity for star-head over the last few years. It is popular among woodworking applications because of its reliability. It can also accommodate more torque.
Torx wood screw

By Material Type

Manufacturers use steel, stainless steel, and brass for these items. They have different applications. You can quickly drive these into a board with minimal stripping.

  • Steel – Steel is the most common material available. Pre-drilling is not a requirement to fit these into most wooden applications. Hardened steel or zinc-plated offer more durability and corrosion resistance.
  • Stainless Steel – The main advantage of using stainless steel is resistant to moisture. These are available in different heads, depending on the application. 
  • Brass – These have an attractive physical appearance. Most carpenters use this as an alternative to steel in places with naturally occurring acids. They are best for outdoor applications because of their high levels of corrosion resistance. 
long wood screws

4 mistakes to avoid when choosing

Choosing the right one is essential in every application. Each size has its uses. Generally, choose a thickness that can enter at least half of the material.

Incorrect material and grade

3-inch washer head wood screws

Each type has a distinct property appropriate for a specific application. Stainless steel is corrosion-resistant, while grade 316 stainless steel has higher resistance from corrosion. It makes it excellent for saltwater applications. 

Reactive materials

Putting two or more reactive metals together will weaken their integrity. Putting stainless steel and aluminum together in salt water will make an unstable balance, weakening the material and leaving it susceptible to rust. 

Mixing metric and imperial sizes

Always check the sizes before installing or purchasing your materials. Do not mix metric readings with imperial readings or vice versa because these will create inaccuracy and confusion with your measurements. 

Wrong driver size

Using the correct driver size reduces deformation chances and over-screwing. A loose driver increases the chances of stripping and camming out. 

The following are the common ones available in the market.

fastec wood screws

#6

Gauge #6 is not the smallest diameter in the market but is common among small objects. It has a thread size of 0.13 inches and a length ranging from 0.5 to 1.5 inches. The typical applications are toys, drawer slides, light fixtures, and hinges.

Recommendation – SG TZH #6 Self-Tapping Wood Screw

Pros

  • Strong and durable, will last a long time.
  • We like the precision threads.

Cons

  • The screws arrived in a small plastic bag squeezed into a box.
SG TZH #6 Self-Tapping Wood Screw
You have plenty of options to choose from.

#8

Gauge #8 is the most common size in the market. It has a wide application, making it common in several wooden objects. Items such as cabinets, furniture, and other light constructions use the #8. These have lengths ranging from 0.625 to three inches.

Recommendation – Bolt Dropper #8 Stainless Steel

Pros

  • The package arrived quickly.
  • Highly resistant to rust.

Cons

  • The screws left stains on our hands.

#10

Gauge #10 are for larger and heavier objects, which you will find in many construction jobs. Moreover, you will also find it on the patio and outdoor furniture. These have a thread diameter of 0.19 inches.

Recommendation – Deck Plus #10

Pros

  • Affordable price.
  • Easy to install with the star-drive feature.

Cons

  • Some screws had their heads deformed.
Sale
Deck Plus #10
The best screws with a 4-layer epoxy coating.

#12

Gauge #12 works great on woodworking projects, specifically when connecting two or more points. The one we recommend below is 100% stainless steel, which is resistant to rust. 

Recommendation – LIONMAX #12 Woodworking Kit

Pros

  • Wide application.
  • You can save drilling time with the self tapping point.

Cons

  • There is no customer support available.
LIONMAX #12 Woodworking Kit
You will save lots of time with these self-tapping screws.

#14

Gauge #14 is excellent for outdoor and indoor use. The stainless steel material prevents corrosion from building up around the shaft. 

Recommendation – Bolt Dropper #14 Stainless Steel

Pros

  • Corrosion resistant feature makes them ideal for external applications.
  • Pure stainless steel without coatings.

Cons

  • You need specific screwdrivers for these screws.
Bolt Dropper #14 Stainless Steel
Screws that you can depend on.

6/32

It has a black phosphate coating, enabling higher resistance to corrosion and rust. Ideally, we recommend using it in renovations and fixing wooden flooring. It also works with plastic and soft metals. 

Recommendation – MR SCREWS #6-32 Stainless Steel Self-Tapping

Pros

  • We used these screws for many applications.
  • The black phosphate coating is an unique feature.

Cons

  • We didn’t receive 330 screws in our package.
MR SCREWS #6-32 Stainless Steel Self-Tapping
High-quality screws coated with black phosphate.

8/32 screw diameter

These have sharp tips but are not corrosion-resistant. We recommend using it indoors and away from moisture and direct contact with water. 

Recommendation – Snug Fasteners #8-32 Black Phillips Truss Head

Pros

  • Superior quality.
  • They have a sharp point.

Cons

  • Not ideal for outdoor use.
Snug Fasteners #8-32 Black Phillips Truss Head
Besides being practical, these screws also look cool.

4/40

The 4-40 size is ideal for different applications. It includes chipboards, fiberboards, hardwoods, and softwoods.

Most manufacturers make these using a single thread, allowing for easier and quicker insertion. It is also not limited to wooden applications because it works with metal or plastic. Those using zinc coating or a stainless steel material are unlikely to rust

10/32

The 10-32 has 32 threads per inch (TPI). It roughly translates to a diameter of 0.1875 inches. We recommend using the 10-32 in indoor and outdoor woodworking of:

  • shelves
  • tables
  • benches
  • door hinges
  • and fence panels.

You can use it outdoors if you have a corrosion-resistant screw. Otherwise, we recommend staying away from moisture and water.

2/56

The 2-56 has around 56 threads per inch (TPI). This type is not very common in woodworking. However, you will rarely find it in small objects or items. 

10/24

The 10-24 diameter is for general woodworking purposes. Some manufacturers produce corrosion-resistant items that you can use in wet and dry applications. Please check with the manufacturer before taking further action.

A flat-head type will work great in furniture because of its flushed design. We also recommend using it in fences and decks.

Recommendation – Hillman #10-24 Galvanized Wood Screw

Pros

  • Excellent corrosion protection.
  • We love the galvanized exterior of these screws.

Cons

  • Some of the screws were bent during delivery.
Hillman #10-24 Galvanized Wood Screw
With 750 pieces included in the package, you will never run out of screws again.

M3

The M3 size is excellent for woodworking jobs and do-it-yourself projects. These are typically corrosion-resistant, durable, and secure. The deep threads you will find here prevent stripping and provides a good hold. 

Recommendation – Erioctry M3 Stainless Steel Wood Screw

Pros

  • Great for DIY projects.
  • Made with high-quality stainless steel.

Cons

  • Package took a long time to arrive.
Erioctry M3 Stainless Steel Wood Screw
Deep threads on these screws will help you get the job done faster.

M4

The M4 size is common among assembling wood pieces, such as:

  • chairs
  • tables
  • and furniture.

We recommend drilling a small hole before tapping

4 screws on a table

We will be happy to hear your thoughts

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