Cutting 4×4 with Miter Saw

Cutting 4x4 with Miter Saw
The 4x4s are some of the most common pieces of wood used in construction, particularly fence posts. The 4×4 is both thick enough to be used for fencing, yet still light and easy enough to work with to make the job easier.

However, finding the right size blade to make the cuts with your miter or circular saw means doing a little research to ensure you get the proper one. What follows are some tips that will help you find the right size saw to efficiently cut 4x4s.

What Size Saw to Cut 4×4?

Power saws such as circular saws and miter saws make the cutting job effortless. However, you should have the right tool for the job.

So, what size saw do you need to cut a 4×4 fence post?
DEWALT 12-Inch Miter Saw, 15-Amp, Single Bevel, Compound (DWS715)
Recommended 12-inch Saw for 4×4 – Click to See Price

A 12-inch miter saw is the best saw to cut 4×4 posts in a single pass. This is before you install them on the ground. You need to use a circular saw to cut a 4×4 post in the ground. Depending on the blade size you may need to make several passes to achieve a clean cut. You can also use a bandsaw and table saw for cutting 4×4 lumber.

Can a 10” Miter Saw Cut a 4×4?

The 10-inch miter saw is a common power tool used for cutting different sizes of wood. This includes the 4×4 as the cutting depth of a 10” saw is roughly 5 ½”. This means that you can make the cut in one pass. However, because of the depth, it will not be an easy cut to make. This is especially true if you are using a free-standing saw and not one that is stationary.

10-inch stationery saw with the proper preparation has just enough capacity to make the cut, but you would be better off with a 12” blade. If you are going to use a 10-inch saw for this task, you will have to adjust your blade-guard or in some cases completely remove it. This is a major safety concern and because of this, I do not recommend using a regular 10-inch saw. The size of the 12” miter saw blade is such that it can easily cut through a 4×4. So, if you want to avoid the extra work, then a 12” saw is recommended.

But what if you do not have access to a 12” saw and you need it cut right now? If that is the case, then the 10” saw will have to do. Be prepared to make an additional pass if you want a clean cut.

There is one exception, the sliding miter saw. Because it slides, it can extend the depth of the cut into the full width of the wood. The result is that you can make a cleaner cut with a 10” sliding saw. Keep in mind that this type of miter saws are more expensive compared to standard versions. If you are cutting 4x4s regularly, then you want to invest in a 12” saw or a 10” sliding compound miter saw.

Makita LS1019L

Makita 10-inch Dual-Bevel Sliding Compound Mitre Saw
Makita 10″ (Sliding) – Click to See Price


However, you are only making occasional cuts of 4x4s, then it probably isn’t worth investing in a more expensive saw or sliding system.

But what if you do not have a 10” blade for on your chop saw? Can the job still be done with a 7 ¼” saw?

Can a 7 ¼” Miter Saw Cust a 4×4?

The 7 ¼” blade is typical with circular or miter saws, but the maximum cutting depth is roughly 2 ½”. This means that you cannot make a complete cut through a 4×4 with one pass. You will need at least one more pass and possibly more to make a complete cut through a 4×4.

If you need a perfectly straight edge, this can be complicated as it means lining up each cut perfectly. If such precision is not needed, then you can simply mark the area that needs to be cut, line up and go. However, if you need the edge to be perfectly straight, then you will need to follow a few tips.

Mark the Cutline:

A square will help guide the pencil. Make sure the line is as even as possible. To make a straight line, do the following.

  • Put the shoe flat of the saw on the face
  • Line up the blade with the cutline
  • Put the square on the corner of the post and place it against the shoe
  • Hold the square and pull the saw slightly away
  • Pull the trigger and push the saw blade into the cutline

Once you have made the cut, you can use the kerf to line up the square. Start by making a single rotation of the post towards you. Then put the blade in the kerf, put the square against the shoe and hold tight. Pull the blade from the kerf and then pull the trigger to start the blade. The edge of the square will help keep the cut aligned.

Keep repeating until the post is fully cut. The result should be a straight line across with minimal issues. Remember that you can use this technique on any size timber where the blade can at least reach the middle of the post.

The same techniques applied with a miter saw will work with a circular saw as well. You will need to be careful when handling wood that is thicker than the depth of the blade. If you can, get a blade large enough to cut through the lumber in a single pass.

What is the Best Saw to Cut a 4×4 Post?

Cutting 4×4 with Circular Saw

A circular saw or skil saw is the best saw to cut the top of 4×4 fence posts on the ground. They are sufficiently accurate and easy to use. The only downside is that you have to make at least two passes to cut through the fence post.

In order to make your cuts as precise as possible, use a speed square to mark the cut line clearly.

12-inch Miter Saw

The two best miter saws to cuts a 4×4 post uses either a 12-inch or a 10-inch blade on a sliding miter saw. Both power saws have the cutting capacity to cut a 4×4 in one pass. A single pass is preferable to maintain the straight lines and integrity of the cut. If the edges are not important, then you can use a smaller blade and make multiple passes.

Another advantage is the ability to do angle cuts precisely. However, the 12” blade can do the job in a single pass which makes it easier to use and more desirable, especially if you are frequently cutting 4x4s. In addition, the 10” blade on a sliding miter saw can also work just as well. Just keep in mind that a 12” blade is more expensive compared to a 10” blade. And the dual bevel sliding compound miter saws are more expensive compared to a standard version.

Should I get a 10” or 12” Miter Saw?

It all comes down to the frequency and accuracy of the 4x4s you wish to cut. For infrequent cuts that do not have to be 100% precise, then a 10” or even a 7 ½” standard blade will do. You will make multiple passes and the cuts may not line up perfectly, but in a pinch, they can do the job.

For more frequent cuts, it’s better to invest in a 10” sliding miter saw or a 12-inch saw. This will provide a single, straight cut that offers more precision which is perfect for attaching the 4×4 to other material in a straight, even line.

Can you cut a 4×4 with a Table Saw?

Yes. A table saw with a 12-inch blade can cut 4×4 in one pass. However, a 10-inch blade can cut only 3-⅛ inch deep which is not sufficient to cut the 4×4 in one pass. In such cases, you have to flip the lumber and pass a second time to complete the cut.

The main advantage of a table saw is its ability to do rip cuts. That means you can cut a 4×4 lengthwise with a table saw or you could also use a vertical bandsaw for this. A bandsaw is a better option for resawing (slicing thin strips of wood).

Can I use a Chain Saw?

You can use a chainsaw to cut the 4x4s if you are very particular about the accuracy and aesthetics. Unlike a circular or table saw, the chain saw is difficult to control and produces rough surfaces. It is an excellent tool for rough cuts.