How strong are pocket hole screws?

Have you ever built a seating bench or a chair using a Kreg Jig pocket hole system and wondered, how much weight can this bench hold? When working on my DIY projects, that thought always crosses my mind. What if someone sits on that chair that I build and that chair just crumples to the ground? That would be really embarrassing. So I did some research on how strong are pocket hole screws and this is what I found.   

According to a study conducted by the RADCO testing division, a common 90-degree pocket hole joint using a 2×4 rail that is attached to a 4×4 post could hold 1361 lbs before failing. However, using the same setup, if you apply pressure from the bottom of 2×4, the same side as the holes, this 2×4 holds only 410 lbs. 

When it comes to woodworking, not all screws are created equal. The type of screws to use will depend on situations, and some can be cheaper and easier to use than other types.

What are Pocket Hole Screws?

A pocket hole is, in a nutshell, a hole drilled at an angle that forms a “pocket” for the screw. The pocket hole is an advanced and precise toe-nailing that involves the pocket hole jig, which allows us to drill into the wood at an angle to produce the pocket to house the screw head.

The pocket hole screws, on the other hand, are designed as a joint between two adjacent boards. The idea is to have both boards to have the angled pockets drilled to them to hide the screws from sight. Since the screw must hold the two boards together at the joint, this whole system must be sufficiently secured.

Why Use Pocket Hole Screws?

The pocket hole screw system is especially important in DIY projects because the pocket hole screws allow very strong joints but the process of creating it is fairly simple. You don’t need any expensive tools or learn special skills for this: all you need is a Kreg jig you can use to drill angled holes on your wood to house the screws securely,

There are other techniques you can use to secure two different boards from dovetails, half-lap joints, and biscuits, among others, but most of these other techniques are typically time-consuming and would require expensive tools to make.

If woodworking is not a full-time job, then using pocket hole screws are the easiest and the most cost-efficient method. Also, pocket hole screws are strong enough to hold the board together, and you won’t need to use clamps (which can be quite expensive).

How Strong Are Pocket Hole Screws?

Below, I include a chart to display the strength of pocket hole screws based on our test using 4×4 (Post) and 2×4 (Rail) pieces with four different methods/joint types and three different screw positions for each method. This chart was based on a Kreg Jig Tool Company test conducted by the RADCO testing division.

Cedar lumber pocket hole system strength test results

As you can see from the image, there are four different joint types of pocket hole screws. Each joint was assembled as a Post (4×4) and Rail (2×4) system. Each configuration was tested with Cedar lumber as follows:

  • Type 1: the Post and Rail form a 90-degree angle with two pocket holes. The short sides of the Rail sit flush to the sides of the Post.
  • Top Pressure: force is applied to the long side of the Rail (opposite to the pocket holes), can hold 1,361 lbs of pressure
  • Side Pressure: force is applied to the shorter side of the Rail, can hold 1,196 lbs of pressure
  • Bottom pressure: force is applied in a similar way to the top pressure, but the force is applied to the same side as the hole, can only hold 410 lbs
  • Type 2: the Post and Rail are positioned in a similar way to type 1, but the Rail is rotated 90 degrees lengthwise:
  • Top Pressure: force is applied to the long side of the Rail (opposite to the pocket holes), can hold 1,325 lbs of pressure
  • Side Pressure: force is applied to the shorter side of the Rail, can hold 1,025 lbs of pressure
  • Bottom pressure: force is applied in a similar way to the top pressure, but the force is applied to the same side as the hole, can only hold 460 lbs
  • Type 3: the Post and Rail form a T-shape with one pocket hole positioned on the opposite sides of the post.
  • Side Pressure: force is applied to the short side of the Rail, just below the Post. Can hold 1,154 lbs
  • Bottom Pressure: uplift force is applied to the Post from the bottom, can hold 1,025 lbs.
  • Type 4: the Post and Rail form a T-Shape, with two pocket holes positioned on the opposite sides of the Post:
  • Bottom Pressure: uplift force is applied to the Post from the bottom, can hold 1,961 lbs.

About Kreg Jig

Kreg Jig is a proprietary eponym or generic trademark to actually describes pocket hole jig because the brand Kreg makes the most popular jig on the market today. So, understand that when people say “Kreg jig”, it usually refers to the pocket hole jig.

A pocket hole jig, as briefly discussed above, is a tool that is used to create a pocket in a piece of wood where we can then attach a screw to join two boards together. The Kreg jig can guide your drill bit to the right angle and can be moved quickly from spot to spot, so they are very versatile.

Every Kreg jig contains at least these essential components:

  • A drilling guide: The drill guide holds a bit at a proper angle for drilling pocket holes.
  • A stepped drill bit: A 3/8″ drill bit with narrower tip.
  • Depth collar: The depth collar is used to set how deep you want the hole to be drilled
  • Long drive bit: For screwing-in the screws

Using a Kreg jig, we can quickly drill and attach all hole joints faster than with other methods, in general, it would only require 30% of the time it would take using other methods like biscuits or dovetails. Also, Kreg jig allows us to attach the boards using pocket hole screws that are stronger than merely gluing the boards together (as discussed in the above section).

However, that’s not saying the pocket hole joinery using the Kreg jig doesn’t have any downside. First, they need specialized screws to fit the pocket hole, and the process will leave a hole on the boards that might not be aesthetically pleasing.

Different Types of Kreg Jigs

Kreg is, as mentioned, a brand that produces pocket hole jigs, and they actually offer several different Kreg jig products, namely:

  1. Kreg Jig Foreman: for small to large scale projects (up to 75+ pocket holes) with built-in clamping, storage, and high-speed pocket holes feature
  2. Kreg Jig K5: for small to large scale projects (25-50 pocket holes) with built-in clamping and storage
  3. Kreg Jig K4: for small to large projects (25-50 pocket holes)
  4. Kreg Jig R3: for small projects (10-25 pocket holes)
  5. Kreg Jig HD: for outdoor small-large projects (1-100 pocket holes)

Choosing The Right Pocket Hole Screws Length

You can use this chart below to choose the right screw length according to your board’s thickness:

  • 3/4″ and 1″ screw lengths are for 1/2″ material thickness
  • 1 1/4″ screw length is for 3/4″ material thickness
  • 1 1/2″ screw length is for 1″ material thickness
  • 2″ screw length is for 1 1/4″ material thickness
  • 2 1/2″ screw length is for 1 1/2″ material thickness

35 thoughts on “How strong are pocket hole screws?”

    • Hi Simon, Yes the pocket holes could be used to attach 4″ posts. You’ll just need to figure out the best location for the pocket holes for maximum straight.

      Reply
  1. Hi I’m in the process off making some large boxes out of 3/4 plywood for making wardrobes and having wheel on base can you tell me what system I would use

    Reply
    • Hi James, for 3/4″ plywood you would need to use 1 1/4″ pocket hole screws, but the placement of pocket holes depends on how you’re planning to assemble the boxes. Also the more screws you use the stronger the box will be.

      Reply
      • I like ana White’s videos and like her I also glue my pocket hole joints, even end grain. Do you think this adds much strength?

        Reply
        • Hi Robert, I also use wood glue with pocket holes, but the main reason why I use glue is to keep the boards from coming apart over time. Let’s say you made a chair with pocket holes, and you use it all the time. After heavy use, the joints might come loose, and the chair becomes squeaky. But if you use pocket holes with wood glue, those joints will not come apart.

          Reply
    • James
      Pocket hole jigs are a fine way to make furniture and other products but my problem is finding the screws that adjust to leagth of the project. Especially the size of the head of the screw plus leagth in finding those screws. Sometimes the head does not fit or is hidden unless you sand it down. So were do I find the proper screws.

      Reply
    • Hi Joe, When I build wood projects, I try to use wood glue, especially on projects like a chair or a bench. Wood glue keeps the wood together and prevents pocket hole screws to come lose on furniture like a chair that is heavily used. When the screws come lose the chair will become squeaky. But let’s say some parts of the furniture will need to be disassembled later on, then I would not use wood glue.

      Reply
    • Hi Jeff, Pocket hole screws have a flat head, this makes the screws pull the boards together when driving them it. Drywall screws do not have a flat head, so they will rip open the pocket hole and mess up your boards. So I would not recommend using drywall screws in the pocket holes.

      Reply
    • Hi I just use my kreg jig and my problem is the measurements for length of drill and screws is the wood your screwing into or the wood its going into . And I bought the pocket hole screw pack and they didn’t have 3/4 or 2 in screws and guess which ones i needed. I was using 1/4″ plywood for a table top and 1/2 cedar boards for the sides. Didnt know what would work so I had to do it on the other side and fill in the other holes.

      Reply
    • It wasn’t holding so I went to the next size and I bought 1/2 quarter rd mounding held that with Brad nails on 1/4ply turned it and made more holes and used 1/2 plus a little more on the bit and used 2 1/2 screws and glue. That worked but brad nails were a little long but I managed . This was a scrap wood project for a lego table for grandson came out ok. Next is a real furniture piece with instructions. Oh screw driver was to long to get screws in on the short end of table (angled table to fit space) what can you use in that case. Try square head screwdriver that slightly worked.

      Reply
  2. Great article, I just did a small base for my 180 gallon fish tank, I was using treated wood I had issue with the pocket screws doesn’t stop when driving in when the screw head are tight enough, I believe because of the wood being soft after treated, is there any specification on how much ft lb to be used or what setting to use on drill when driving the screws.

    Reply
    • Are you using pocket hole screws with a flat head? If you’re using regular wood screws for pocket holes, it will not work, because regular wood screws do not have a flat head and it will split the wood. Using pocket hole screws on treated wood is perfectly fine. I’ve done it many times.

      Reply
  3. Knowing that flat head screws are a must for strong pocket hole joints, is there another more affordable brand screw that you’ve come across other than Kreg?

    Reply
  4. I am building a storage bench with my son using 3/4″ veneered plywood and notice the workpiece shifts a little – approx 1/32″ when we tighten the screws. All settings are correct on the pocket depth and hole position (3/4″). An suggestions to eliminate (or compensate) for this shift?

    Reply
  5. This article is sorely lacking a basic fact and I wonder how a fairly lengthy article about pocket hole has no mention of the word “grain”. Pocket holes main purpose is not to hide screws but to do away with screwing towards the wood’s end grain. Therein lies the pocket hole strength when doing butt joints.

    Reply
  6. I am constructing a storage bench for the end of a queen size bed. The top will be 3 white pine 1×6 that are 50” long. When the boards are glued and kreg screwed together the lid will be 16.5” wide. The lid will overhang the bench box by 1/2”. Will this lid be safe for an adult to sit on?
    Your article is the best I’ve seen. Thanks

    Reply
  7. Jess, Pocket hole screws are very strong, but it depends on the design of the bed if it will support 300kg. You don’t want to pull all the weight on just few screws, you want to spread it out on many screws.

    Reply

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