Rockler Corner Key Doweling Jig
Posted: Sunday, July 19, 2026 at 05:14 PM
Categories: Jigs
I've always had an interest in different types of joinery and I think that spline joints are particularly interesting and appealing. Several years ago, I purchased Rockler's Corner Key Doweling Jig but I never had an opportunity to use it for anything.
I recently built a couple of drawers out of 1/2 inch maple plywood using a Rabbet joint and I wanted an easy way to reinforce the glued joint. I decided to dig out the corner key doweling jig and give it a whirl.
Kinda Disappointed
My overall assessment of this jig is that its a great idea and an interesting design, but I'm really disappointed in the implementation. It requires more setup than what I expect from a jig like this and the materials weren't sturdy enough to allow me to consistently cut solid joints using the jig. This is all explained below.
Basically, this jig allows you to (more or less) accurately drill holes across a corner of a box, drawer, or frame, etc. After you've drilled the hole, you then glue in then cut flush a wooden dowel. This creates a secure cross support for the joint you drilled across. If you're doing this simply to reinforce the joint, it doesn't matter what wood you use for the dowel. If you're doing this for aesthetics, trying to improve the look of the joint, then you use a dowel of a contrasting color or type of wood.
Basic Operation
After you assemble the jig, more on this later, you basically clamp the jig across the corner and drill your hole. The jig is flexible enough that it allows you to easily configure the distance from the edge and diameter of the drilled hole.
Note: The jig only drills holes at a 45° angle.
Here's the jig mounted on one of my drawers.
As you can see on the back of the jig, there's a sliding component of the jig that allows you to control the distance from the edge of the wood panel to the drilled hole. You use this to adjust the jig for the thickness of the wood, but you can also use it to deliver different visual effects on the piece, for example, drilling two holes at different distances from the edge.
Image 1: Getting ready to drill a corner hole
The jig includes three difference sizes of extended length drill bits, 1/8, 1/4, and 3/8 inch in diameter.
Rockler recommends against drilling all the way through the back of the jig, so they suggest that you use a drill depth stop to control how far it drills past the corner. For this I used one of the Infinity Tools Adjustable Drill Depth Stops that I keep in my shop for this purpose.
Image 2: Setting the drill depth
Jig Setup
Before you can use the jig, you have some setup to do. Rockler made some design and product decisions that pushes responsibility to the consumer (you) to make the product ready for use.
The jig doesn't ship with any backer blocks, blocks of MDF the jig holds against the lower hole to keep the drill from blowing out the wood on the way out. With the backer block in place, it holds pressure against the wood at the exit, ensuring a clean hole. The jig requires this, but expects you to do all the work to create them (you'll need at least three of them to use all the available drill/hole diameters). From the jig manual:
Before using the jig, you must attach a 1/2" thick MDF backer board to the front face of the Clamping Block (1) section of the jig. It is recommended that you make a dedicated backer board for each of the three drilling diameters and switch the backer boards whenever you switch Guide Bushings. At a minimum, for each drilling diameter, you must unscrew the backer board, shift it slightly side to side to an undrilled section and reattach it to the Clamping Block. Drill the zero-clearance hole in the Clamping Block backer board before using the jig on your final workpiece.
I don't know about you, but I have a pretty well equipped shop and I don't keep a lot of 1/2 inch MDF lying around. Amazon had some options, but the cheapest one was $31US. I ended up buying a 24" x 48" piece at Home Depot for $28US.
Notice this note in the instructions:
It is recommended that you make a dedicated backer board for each of the three drilling diameters and switch the backer boards whenever you switch Guide Bushings.
Not only do you need one of these for each of the drilling diameters, if you drill using different wood thicknesses, you'll need one for each of those as well for each drill diameter.
Rockler doesn't provide you with any MDF blocks to use for this, so before you can use the jig you must purchase more MDF than you really need then cut a bunch of blocks. What Rockler should have done was included at least one block, but preferably three of them so you can be up and running without any delay and without making any additional purchases.
Another big miss by Rockler is the alignment window. They instruct you to place a long line on a sample box, then:
Set the jig tight against the mitered corner so that the notch in the front of the Drilling Plate perfectly aligns with the mark on the test piece. Carefully clamp the jig in place, using the clamping areas on the Clamping Block and Main Plate. Slightly loosen the screws holding the acrylic hairline indicator in place and adjust the indicator so that it aligns perfectly with the mark on the test piece. Tighten the screws.
Rather than design and manufacture the jig so that the alignment window aligns automatically and stays in place, they made it a lose fit then expect you to make sure its aligned properly before using it.
Image 3: Aligning the alignment window
Usage
To use the jig, you set the depth of the wood you're drilling through, select the drill bit then install the matching collar into the jig.
Once you have that set, you draw lines on the box you want to drill then position the jig over the lines, clamp the jig in place, then drill your holes.
But why? Why do I have to mark up the box in order to be able to drill the holes? If you look at most of the examples shown in the docs and the product pages on Rockler's web site, Rockler expects most people to drill a hole at the top and bottom of the box. So why not build stops into the jig so consumers can drill repeatable holes at the top and bottom of a box without marking up the wood?
Image 4: Marking the box for drilling
Next, you clamp the box to a surface, immobilizing it during the drilling process. You must also clamp the jig in place using multiple clamps. As you can see from the image, I clamped the jig to the side of the box, but didn't clamp the face of the jig to the top of the box. This allowed for some movement when drilling the holes and ruined the holes.
Don't get me wrong, the instructions clearly told me to use multiple clamps, but I guess I'm used to more rigid jigs since I didn't expect I'd need them.
Image 5: Clamping the jig to the box
Here's my results, two sets of holes drilled at a 45° - just what I expected.
Now, the box I'm using is just a test box, I didn't use a clean joint that hid my plywood edges. If I'd done this for real, all you'd see if plywood face on both surfaces. At this point, its up to me to clean up the holes with some sandpaper and erase the pencil lines.
Image 6: Drilled Holes
With the holes drilled, simply apply some glue to an appropriately sized dowel and insert it in the hole.
If you think about it though, in order for the dowel to fit tight in the hole, there has to ve very little additional space between the dowel and hole. You may find that its really hard to get enough glue on the dowel to keep it solidly in place without too much glue leaking out the hole.
Image 7: Inserting a dowel
Because I didn't use multiple clamps when holding the jig against my box, the jig shifted when I started drilling and I ended up with loese holes, or at least loose hole openings. But, even when I did use multiple clamps, the very thin construction of the jig face bent when I drilled my holes and made the entry holes bigger than expected.
Image 8: A dowel poked through a hole
Something Rockler doesn't cover in the jig instructions is how to cut your dowels off flush.
You could use a router and flush trim bit to cut off the excess dowel.
I used a special Japanese flexible hand saw with sharpening teeth on only one side of the saw blade; [something like this](https://www.leevalley.com/en-us/shop/tools/hand-tools/saws/japanese/32932-japanese-flush-cutting-saw){target="_blank"}. The blade bends (not shown bent in the image) so you can hold it flat against the box and cut the dowel off flush.
Image 9: Cutting the dowel off flush
Conclusion
I was not impressed with the quality of this jig. The design seemed good, but Rockler skimped on the implementation. Sacrificing quality to deliver something at a low price.
Looking at the product reviews, you'll see this:
I drilled 56 holes the other day and it worked fine. I did find it needed a larger 3/4 back up board and longer screws to hold the board on. I have 56 more holes to drill tomorrow but this jig is up to the task.
This consumer is using the heck out of this jig, they've got so many angled holes to drill that I'm willing to bet they'd pay more for a higher quality product. At a minimum, Rockler should have made the jig sturdier.
Pros
- Really cool product with an interesting design,
- Good options (three different sized drill bits) and reasonable flexibility (different wood thicknesses and hole distance from the edge).
Cons
- Requires that you create your own backer boards before you can use it. A starter set of backer boards should be included automatically so you can use it out of the box. Woodpeckers does an excellent job of this; amy product of theirs that requires backer boards or sacrificial materials, they're included in the box and they offer customers the option to purchase more.
- The packaging doesn't include enough storage so you can store the jig in assembled form in the box and you can store your backer boards with it. To store this product with all the required parts requires a completely different storage container. Rockler knows that every single customer will use this with at least one but likely three backer boards (one for each drill bit size) so they should take that into account with the packaging. Who wants to assemble a jig every time they use it?
- The material should be more rigid or the jig made out of metal. If you're going to use this a lot, you'll want it made out of at least thick aluminum. I would not have purchased it if I knew in advance how flimsy it was.
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