<p>Probably the cleanest way to cut materials like thin plywood is to use utility knife and a straightedge. Mark the lines you want to cut, align and hold tight the straightedge, and make each cut in multiple passes.</p>
<p>Be sure to have a sharp blade in the knife, be patient, and do not use too much force to prevent ripping the plywood. Optionally when you get nearly through you can reverse the piece and gently cut through from the other side to finish the cuts (you will have to do this if you are not using a cutting surface.)</p>
<p>It is best to use a metal straightedge/ruler for this. Plastic or wood will allow the blade to dive into it and ruin the cut. Also, though this is a smaller cut so it is less of an issue, really be sure to hold the straightedge tight throughout the cutting. Its very easy towards the end of a cut to get the pressure wrong and have the straightedge suddenly pivot and again mess up the cut (or worse, a finger).</p>
<p>If you are cutting these boards in place, ie they are attached to the back of the boxes, then you could use the inside edges of the box as the guide but being wood it will be easy to go off course. Instead poke or drill holes in the corners like before but then use the knife to cut through from the other side using the holes as reference.</p>

CC BY-SA 4.0
2024-10-28T16:41:12.150Z
2024-10-28T17:04:09.287Z
2024-10-28T17:04:09.287Z
rebusB
<p>Although this may fall into the category of opinion based, one answer is a relatively inexpensive coping saw. It uses fairly thin high-tooth-count blades which provide for a clean cut. You don't have a huge project which is perfect for this type of saw. Manually operated, easily controlled. One could use a powered version but why spend the extra money? These coping saws are perfect for thin material.</p>
<p>You've noted that you used a &quot;mini-saw&quot; but that's a bit ambiguous. If it is a wallboard cut-out saw, it would have coarser teeth count and be less suited for this task.</p>
<p>Of course, <a href="https://rads.stackoverflow.com/amzn/click/com/B000B3AR04" rel="nofollow noreferrer" rel="nofollow noreferrer">Amazon</a> is one resource:</p>
<p><a href="https://i.sstatic.net/EDdtsXoZ.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/EDdtsXoZ.png" alt="coping saw listed on Amazon" /></a></p>
<p>Image from linked source. US$9.99 Amazon.</p>

CC BY-SA 4.0
2024-10-28T15:13:51.397Z
2024-10-28T15:13:51.397Z
fred_dot_u
<p>A Japanese hand saw has the advantages of having a high tooth count and flexibility. The higher tooth count provides a smoother cut, and the flexibility allows for flush cutting against a surface.</p>
<p><a href="https://i.sstatic.net/OlGapo21.jpg" rel="nofollow noreferrer" title="Product photo of the different features of a Japanese hand saw"><img src="https://i.sstatic.net/OlGapo21.jpg" alt="Product photo of the different features of a Japanese hand saw" title="Product photo of the different features of a Japanese hand saw" /></a></p>
<p><sub>[Source: <a href="https://a.co/d/9m8nCXP" rel="nofollow noreferrer">Amazon's RUITOOL Japanese Hand Saw</a>]</sub></p>

CC BY-SA 4.0
2024-10-30T07:10:19.063Z
While I do believe that you can cut the bottom of a box with such a blade, I'm afraid you would scratch the inside walls of the box. Plus, the box is much too small for such a saw blade to actually fit and be of any use.
Elmy
CC BY-SA 4.0
2024-10-29T14:40:13.037Z
2024-10-29T14:40:13.037Z
agarza
<p>If the sharp utility knife idea doesn't work, then I would roughly drill around the edge and then break out the whole bottom in pieces and dispose of the waste.</p>
<p>This should leave an empty channel around the edges into which you can slip new thin strips of wood, or simply leave as-is.  If you want a ledge there, put in wider strips of wood that overhang as required.</p>
<p>There is a chance the bottom panel was glued in place, which may make it harder to pull the scraps.  If there's a lot of glue, you might find it easier to disassemble the box completely, then chisel the slot clear, and reassemble.</p>
<p>If the height of the box is not important, and you can afford to loose the bottom ~half-inch then run it over the tablesaw on its side four times, so the blade cuts off the floor and the bottom part of the sides.   You could also cut just below the floor and let the floor push out the bottom though this would leave a step in the underside of the walls.</p>

CC BY-SA 4.0
2024-10-30T00:59:18.027Z
2024-10-30T00:59:18.027Z
Criggie
<p>I am looking to cut out a perfect rectangular shape on the inside of a plywood box. I've tried using a drill to create holes in each corner and then using a mini saw to cut it out. However, the result was really messy with uneven sides and I'm looking for a tool that can achieve a cleaner cut.</p>
<p>The area I want to cut out only measures 6.5 cm x 10.5 cm, so I need a tool with a smaller blade. Does anyone have any idea what tool to use and how to achieve this? The wood is very thin plywood that I want to cut out. I've put a black rectangle around the area.</p>
<p><a href="https://i.sstatic.net/MLawYtpB.jpg" rel="nofollow noreferrer" title="Photo of a plywood box with holes drilled in the bottom and a black line highlighting the area to be cut."><img src="https://i.sstatic.net/MLawYtpBm.jpg" alt="Photo of a plywood box with holes drilled in the bottom and a black line highlighting the area to be cut." /></a></p>

CC BY-SA 4.0
2024-10-29T09:46:47.063Z
It seems like you want to take out the bottom (perhaps while leaving the overall height of the box intact). What is the construction of the box like? Wouldn't it be easier to take out the bottom (and if so desired attach a few wooden bars at the bottom of each side to readjust the height of the entire box)?
Joachim
CC BY-SA 4.0
2024-10-30T01:05:48.137Z
@Joachim good point - if one end can be detatched from the box then the floor should slide out easily (resuming no glue)  but those mitre joints look good, I bet they're glued and nailed, and maybe even have a biscuit or dowel hidden inside.  Would be awful hard to do without damage
Criggie
<tool-selection><wood><cutting><woodworking>
Tools for cutting out a perfect rectangle on the inside of small wooden box
Artsywolf
# Tools for cutting out a perfect rectangle on the inside of small wooden box

(Asked by: username_0 on 2024-10-28)

I am looking to cut out a perfect rectangular shape on the inside of a plywood box. I've tried using a drill to create holes in each corner and then using a mini saw to cut it out. However, the result was really messy with uneven sides and I'm looking for a tool that can achieve a cleaner cut.

The area I want to cut out only measures 6.5 cm x 10.5 cm, so I need a tool with a smaller blade. Does anyone have any idea what tool to use and how to achieve this? The wood is very thin plywood that I want to cut out. I've put a black rectangle around the area.

[![Photo of a plywood box with holes drilled in the bottom and a black line highlighting the area to be cut.](https://i.sstatic.net/MLawYtpBm.jpg)](https://i.sstatic.net/MLawYtpB.jpg "Photo of a plywood box with holes drilled in the bottom and a black line highlighting the area to be cut.")

**Tags:** tool-selection, wood, cutting, woodworking

> **Comments:**
> **username_1**: It seems like you want to take out the bottom (perhaps while leaving the overall height of the box intact). What is the construction of the box like? Wouldn't it be easier to take out the bottom (and if so desired attach a few wooden bars at the bottom of each side to readjust the height of the entire box)?  
> **username_2**: @username_1 good point - if one end can be detatched from the box then the floor should slide out easily (resuming no glue)  but those mitre joints look good, I bet they're glued and nailed, and maybe even have a biscuit or dowel hidden inside.  Would be awful hard to do without damage  

---

## 4 answers

### Answer by username_3 on 2024-10-28. Score: 3

Probably the cleanest way to cut materials like thin plywood is to use utility knife and a straightedge. Mark the lines you want to cut, align and hold tight the straightedge, and make each cut in multiple passes.

Be sure to have a sharp blade in the knife, be patient, and do not use too much force to prevent ripping the plywood. Optionally when you get nearly through you can reverse the piece and gently cut through from the other side to finish the cuts (you will have to do this if you are not using a cutting surface.)

It is best to use a metal straightedge/ruler for this. Plastic or wood will allow the blade to dive into it and ruin the cut. Also, though this is a smaller cut so it is less of an issue, really be sure to hold the straightedge tight throughout the cutting. Its very easy towards the end of a cut to get the pressure wrong and have the straightedge suddenly pivot and again mess up the cut (or worse, a finger).

If you are cutting these boards in place, ie they are attached to the back of the boxes, then you could use the inside edges of the box as the guide but being wood it will be easy to go off course. Instead poke or drill holes in the corners like before but then use the knife to cut through from the other side using the holes as reference.


---

### Answer by username_4 on 2024-10-28. Score: 2

Although this may fall into the category of opinion based, one answer is a relatively inexpensive coping saw. It uses fairly thin high-tooth-count blades which provide for a clean cut. You don't have a huge project which is perfect for this type of saw. Manually operated, easily controlled. One could use a powered version but why spend the extra money? These coping saws are perfect for thin material.

You've noted that you used a "mini-saw" but that's a bit ambiguous. If it is a wallboard cut-out saw, it would have coarser teeth count and be less suited for this task.

Of course, [Amazon](https://rads.stackoverflow.com/amzn/click/com/B000B3AR04) is one resource:

[![coping saw listed on Amazon](https://i.sstatic.net/EDdtsXoZ.png)](https://i.sstatic.net/EDdtsXoZ.png)

Image from linked source. US$9.99 Amazon.


---

### Answer by username_5 on 2024-10-29. Score: 1

A Japanese hand saw has the advantages of having a high tooth count and flexibility. The higher tooth count provides a smoother cut, and the flexibility allows for flush cutting against a surface.

[![Product photo of the different features of a Japanese hand saw](https://i.sstatic.net/OlGapo21.jpg "Product photo of the different features of a Japanese hand saw")](https://i.sstatic.net/OlGapo21.jpg "Product photo of the different features of a Japanese hand saw")

[Source: [Amazon's RUITOOL Japanese Hand Saw](https://a.co/d/9m8nCXP)]

> **Comments:**
> **username_6**: While I do believe that you can cut the bottom of a box with such a blade, I'm afraid you would scratch the inside walls of the box. Plus, the box is much too small for such a saw blade to actually fit and be of any use.  

---

### Answer by username_2 on 2024-10-30. Score: 1

If the sharp utility knife idea doesn't work, then I would roughly drill around the edge and then break out the whole bottom in pieces and dispose of the waste.

This should leave an empty channel around the edges into which you can slip new thin strips of wood, or simply leave as-is. If you want a ledge there, put in wider strips of wood that overhang as required.

There is a chance the bottom panel was glued in place, which may make it harder to pull the scraps. If there's a lot of glue, you might find it easier to disassemble the box completely, then chisel the slot clear, and reassemble.

If the height of the box is not important, and you can afford to loose the bottom ~half-inch then run it over the tablesaw on its side four times, so the blade cuts off the floor and the bottom part of the sides. You could also cut just below the floor and let the floor push out the bottom though this would leave a step in the underside of the walls.


---

