Having a folder full of PDFs might look good on paper, but it’s pretty useless for any engineer. You can’t adjust the design, make the part 3D, or change anything about your PDF drawing. You need to convert it into a usable CAD file, like a DXF, DWG, or HPGL, but how do you do that?
In this guide, we’ll teach you the quickest way to convert a PDF to an AutoCAD file. We’ll also explain some issues with this method and introduce a better, more efficient way to do the conversion. Let’s start by explaining why PDFs are so useless in the world of engineering.
Why Can’t Engineers Use PDFs?
As a team of engineers, we wish that PDFs were more useful in this profession. They’re great for sharing manufacturing drawings with machine shops or sending over drawings for peer reviews, but they can’t do much beyond that. In fact, the only useful PDF is one that was created from a drawing CAD file, not the other way around.
A standard PDF is what’s called a “raster image”. This means that it’s made up of a ton of little dots, called pixels.
Any CAD program needs a vector file, or a collection of lines that have a position and length. For that simple reason, PDFs aren’t useful when it comes to making a design, improving a part, or creating a 3D model — you need a vector file to do anything.
The Benefits of a CAD File
With a CAD file, you can do a ton (as you probably know). A vector file will let you change line types, change layers, create dimensions, make a 3D part, and perfect your design.
All of the features that we love about AutoCAD are contingent on having a vector file, not a raster image from a PDF. This is why the PDF to CAD conversion is so important. You really can’t start doing any engineering work until the conversion is done.
The Quickest Way to Convert PDF to CAD File
In our experience, the quickest way to convert a PDF into an AutoCAD file is by using the PDFIMPORT command. In most cases, it’s a very fast conversion. We should mention that it only works on 2017 AutoCAD or newer, so legacy users can’t access this shortcut.
If You Have the PDF Opened in CAD Already
If you have a pdf opened on your AutoCAD, you’ll notice a PDF Underlay tab on your ribbon, all the way to the right. Clicking this will let you turn on and off layers, change colors, and access PDF Import. Click Edit Layers and turn off everything except for your object layers. Now, click PDF Import and drag a box around the part of the PDF you want to turn into a CAD file.
If You Want to Import a Full PDF Drawing
Let’s say you want to import a full site layout or building plans. In this case, you would also want all the text, layers, and information on the PDF. Type PDFIMPORT in your command bar and type File. This will open a file explorer, so navigate to the folder that your PDF is saved in.
Open it and you’ll see a page where you can choose the sheet number, specify the scale and access different settings. Pick your sheet, make sure you’re clicking the Raster images box, and keep the scale as 1, then click OK.
Now, the full PDF is saved as a vector file in AutoCAD. As you click around your drawing, you’ll find a number of polylines that are combined to make your part. Feel free to use the JOIN and SPLIT commands to make each line perfect.
Issues With AutoCAD PDFIMPORT
Even though the PDFIMPORT command is so handy, it falls short in a lot of regards. In most of our raster to conversion projects, we can’t even use this command. Let’s discuss some issues with AutoCAD’s PDFIMPORT command.
Text Imports as Drawn Shapes
The first thing you’ll notice is that all the text in your PDF is inserted as drawn shapes, not text in AutoCAD. This might seem like a small issue, but you’ll have to redo all the text in your drawing. You won’t be able to move, change, or scale the text until you redo it.
You Won’t Be Able to Extrude
In almost any PDFIMPORT, there’s going to be an area where lines aren’t perfectly connecting. With a small gap, you won’t be able to extrude a seemingly closed shape.
You might think this is a small hiccup, but it’s a bigger problem.
Why? Well, AutoCAD doesn’t show you where the gap is. You need to zoom in incredibly close and trace every line, looking for the smallest gap.You could spend an hour tracking down all of the gaps and closing the object. With that wasted time, you could have redrawn the full part.
A Messy PDF Is a Nightmare
If you scanned a drawing in order to create a PDF, you might be in trouble. Without a super clean PDF, AutoCAD gets confused. Every smear, shadow, and smudge on your scanned PDF becomes a line in AutoCAD that you have to deal with.
This could involve deleting dozens of scanning issues and artifacts in your final AutoCAD file. We’ve had times when a smudge intersected with the drawn lines of the file, and it was time-consuming to separate the two and redraw that section.
Lines Likely Won’t Be the Right Dimensions
Time to talk about a huge issue that you’ll likely deal with: dimensions and scales. Since PDFs don’t have a way of preserving the dimensions of lines, your AutoCAD file could have some strange numbers as you try to dimension your piece.
This is an even bigger issue if the PDF wasn’t made from a scaled drawing to begin with. How are you supposed to dimension a 2D manufacturing drawing in AutoCAD if the initial model isn’t scaled correctly?
You can’t. The worst part is that you might not notice this discrepancy until the last minute. By then, who knows how long you spent cleaning up the imported PDF.
You Still Need to Do a Lot of Cleaning
Although the conversion process is done in a few seconds, you still need to spend a lot of time cleaning up the drawing. We haven’t had a perfect conversion any time we tried using this command.
You still have to connect lines, change layers, add in blocks, redo all the text, change line styles, and redraw damaged lines. In some cases, you might redo 50% of the imported drawing after finding these issues.
It’s simply not worth the headache — you’re inevitably going to waste time and spend money fixing problems that shouldn’t exist in the first place. This shortcut is great for small and very simple parts, but it falls short for most engineering parts.
Warning: Don’t Use Other Programs for PDF to CAD Conversions
Some people try to make the process even quicker by using third-party software to do the PDF to CAD conversion for them. This could be a website where you upload your files, or a program that you download that supposedly does the conversion.
It’s a very bad idea to use any other program for your PDF to CAD conversions. For one, the conversion could result in the same issues we just described with PDFIMPORT, so what’s the point? But, more importantly, these programs can steal your drawings and designs, and there’s nothing stopping them.
When you upload a PDF, the website can take your drawing and sell it to the highest bidder or make a knock-off of your product using your dimensions. It’s incredibly dangerous, and we highly suggest that you never try it.
The Best Way to Convert PDF to CAD File
The industry standard way to convert a PDF to CAD file is by manually redrawing the part, using the PDF as a reference. The best way to achieve this is to work with an outsourced CAD company, like CAD/CAM Services.
We have converted millions of PDFs into CAD files during our decades in business. We know what it takes to deliver CAD Perfect conversions, and it’s a big focus of our business. We want to give you perfect CAD files that can start working for you today.
Whether you have one or one thousand PDFs that you need to convert, you should always start with CAD/CAM Services. We have a team of over 100 engineers and draftsmen who work 24/7 at our facility to deliver the best results possible.
How does it work? It all depends on what you’re starting with. You can either have us scan your Mylar hand drawings or send us a stack of PDFs. From there, we’ll manually draw each file in your 2D or 3D CAD program of choice. Our engineers peer-review each drawing to make sure it’s perfect, then we send it back to you.
We never take shortcuts or use third-party software that could jeopardize the confidentiality of your parts. We respect your intellectual property, so we always manually redraw parts.
You can pay us on a per-project basis, which means you only pay for the engineering time that you receive. This process can save you a ton of time and money. We focus on accuracy and turnaround times, so we know you’ll be impressed when you choose CAD/CAM Services.
Now you know how to quickly convert a PDF to a CAD file. As we described, there are some shortcomings associated with AutoCAD’s built-in feature or using third-party software — we only recommend manually doing the conversion or bringing in an outsourced company like CAD/CAM Services.
We are a full-service engineering and design firm that’s here to handle all of your CAD work. No matter how big or small your project is, you can trust our team and get a free quote today.
This article was last Updated on June 15, 2023