Loose tenon joinery, also called floating tenon joinery, is a simple and effective way to build strong furniture frames, doors, and other woodworking assemblies. Instead of cutting a mortise in one workpiece and forming a matching tenon on the other, you cut an accurately aligned mortise in both pieces and connect them with a separate loose tenon.
This approach has some practical advantages. Both workpieces can be cut to their finished dimensions before you start the joinery, and there are no tenon shoulders to cut and fit. The challenge is making two mortises that line up accurately.
That's where the BeadLOCK Pro loose tenon system comes in.
The BeadLOCK Pro is essentially a precision drilling and mortising jig that lets you create matching mortises with a hand-held drill. In addition to standard BeadLOCK joints, the Pro system can make smooth-sided mortises for shop-made loose tenons or even traditional mortise-and-tenon joinery.
What Is BeadLOCK Loose Tenon Joinery?
A standard BeadLOCK joint uses a series of precisely spaced, overlapping holes to create a mortise with a distinctive corrugated shape.
A matching BeadLOCK loose tenon fits between mortises drilled into the two mating workpieces. The shape of the tenon matches the overlapping holes, creating a large amount of mating surface inside the joint.
The basic BeadLOCK system acts as a drilling guide, making it possible to create these mortises accurately with a hand-held drill rather than a router or dedicated mortising machine.
The BeadLOCK Pro expands on that idea by providing interchangeable guides that allow you to create several different styles of mortise-and-tenon joinery.
Why Use Loose or Floating Tenon Joinery?
The big advantage of loose tenon joinery is simplicity.
With a traditional mortise and tenon, you cut a mortise in one part and form a matching tenon on the other. That tenon also affects the dimensions of the workpiece because you need enough extra length to create it.
With a loose tenon, both mating workpieces receive mortises. A separate piece of tenon stock bridges the two.
That means you can cut the project parts to their finished dimensions first. There's no need to account for the length of an integral tenon, and you don't have tenon shoulders to cut and fit.
The method is particularly useful for frame construction, where you may need to repeat the same joint many times.
How the BeadLOCK Pro Jig Works
The BeadLOCK Pro resembles a heavy-duty doweling jig.
Two steel reference plates are connected by a pair of guide rods. An adjustable carriage slides along these rods and accepts interchangeable drilling and mortise-paring blocks.
The reference plates position the jig on the workpiece while the guide block controls the location and spacing of the holes.
The result is a simple system for creating repeatable mortises without requiring a large stationary machine.
Align the BeadLOCK Jig
Accurate loose tenon joinery depends on the mortises in the mating workpieces lining up correctly.
Alignment marks on the drilling block provide a reference for positioning the jig on your layout marks. Once you've marked the joint location on both workpieces, use these references to position the BeadLOCK Pro consistently on each part.
This ensures that the two mortises align when the joint is assembled.
How to Make a BeadLOCK Mortise
A standard BeadLOCK mortise is created by drilling two sets of overlapping holes.
The drilling block contains a row of evenly spaced guide holes that position the drill bit automatically.
Step 1: Drill the First Set of Holes
Position and secure the jig on the workpiece using your layout marks for reference.
Drill through the first set of guide holes to the required mortise depth. A stop collar on the drill bit provides consistent depth from hole to hole.
Step 2: Shift the Drilling Guide
After drilling the first set of holes, reposition the drilling block to its second indexed position.
The jig automatically establishes the required offset, so there's no need to manually measure the spacing.
Step 3: Drill the Second Set of Holes
Drill the second series of holes.
These holes overlap the first set, producing the characteristic BeadLOCK mortise profile.
Because the spacing is controlled by the jig, the size and configuration of the mortise are repeatable from one workpiece to the next.
How to Make a Smooth-Sided Mortise with BeadLOCK Pro
The Pro system isn't limited to the corrugated mortises used with BeadLOCK tenon stock.
You can also turn the drilled opening into a traditional smooth-sided mortise.
After drilling the mortise, remove the drilling block and replace it with the mortise-paring block.
Use the Paring Block to Guide a Chisel
The opening in the paring block matches the diameter of the drill bit and acts as a guide for your chisel.
Use a sharp chisel against the guide to remove the small ribs of material remaining between the overlapping holes.
This quickly turns the BeadLOCK opening into a straight-sided, accurately sized mortise.
You can leave the ends of the mortise rounded for a loose tenon with matching rounded ends, or use the paring guide to square the ends.
Use BeadLOCK Pro for Shop-Made Loose Tenons
Once you've created a smooth-sided mortise, you aren't limited to proprietary BeadLOCK tenon stock.
You can make your own smooth loose tenons from straight-grained hardwood and size them to fit the mortises.
This gives you more control over the dimensions and material of the tenon. It also makes it possible to use the BeadLOCK Pro as a general-purpose loose-tenon mortising jig rather than only for standard BeadLOCK joints.
Smooth-sided mortises up to about 3" long can be made using the drilling and paring blocks. For longer mortises, the jig can be repositioned along the workpiece.
Use BeadLOCK Pro for Traditional Mortise and Tenon Joinery
There's another useful option.
A smooth-sided mortise created with the BeadLOCK Pro doesn't have to receive a loose tenon. You can also use the jig to cut the mortise half of a traditional mortise-and-tenon joint.
Make the smooth-sided mortise with the drilling and paring blocks, then cut a conventional tenon on the mating workpiece to fit.
That versatility lets the same jig handle BeadLOCK joints, loose tenon joints, and standard mortise-and-tenon joinery.
BeadLOCK Pro Mortise Sizes
The original BeadLOCK Pro kit featured in this article includes drilling and paring blocks for making 3⁄8"-wide mortises.
Accessory guide packages expand the system to 1⁄4" and 1⁄2"-wide mortises. These include the corresponding guide blocks, drill bit, and stop collar.
Having several mortise widths makes it possible to scale the joint to match the size and strength requirements of different projects.
BeadLOCK Tenon Stock
There are two ways to get the matching corrugated tenons used for a standard BeadLOCK joint: Buy ready-made tenon stock or make your own.
One limitation of the system is that standard BeadLOCK tenon stock is produced in predetermined dimensions.
The tenon widths discussed with this version of the system are:
1⁄4"-wide mortise: 1 1⁄2"-wide tenon stock 3⁄8"-wide mortise: 1 3⁄8"-wide tenon stock 1⁄2"-wide mortise: 1 1⁄4"-wide tenon stock
If a project calls for a larger or more substantial joint, you can use two BeadLOCK joints side by side rather than relying on a single wider tenon.
How to Make Your Own BeadLOCK Tenons
If you use a lot of BeadLOCK tenon stock, making your own can be a practical alternative.
A dedicated BeadLOCK router bit creates the same corrugated profile found on manufactured tenon stock.
Making your own also lets you select the wood used for the tenons rather than being limited to commercially available stock.
Step 1: Prepare the Tenon Blank
Start with a long, straight blank sized to the required thickness and width of the finished tenon stock.
Making a long strip is more efficient than trying to shape individual tenons.
Step 2: Rout the BeadLOCK Profile
Set up the BeadLOCK profile bit in the router table and rout one face of the blank.
Flip the blank over and rout the opposite face.
The resulting corrugated profile matches the overlapping-hole mortises created by the BeadLOCK jig.
Step 3: Cut the Tenons to Length
Once the long strip has been profiled, cut individual loose tenons to the length required for your joints.
You can now use the shop-made tenons just like commercially produced BeadLOCK tenon stock.
Is BeadLOCK Pro a Good Choice for Loose Tenon Joinery?
One of the biggest advantages of the BeadLOCK Pro is that it provides an approachable way to make accurate loose tenon joints without a dedicated mortising machine.
The jig controls the position and spacing of the drilled holes, which takes much of the guesswork out of aligning mortises in mating workpieces. And once you've learned the basic setup, the same system can be used for several types of joinery.
Use the standard drilling block and you can make traditional BeadLOCK loose tenon joints. Add the paring block and you can create smooth mortises for shop-made floating tenons. Or use those same smooth mortises with conventional tenons for traditional mortise-and-tenon joinery.
That versatility is what makes the BeadLOCK Pro more than simply a drilling jig. It's a compact mortising system that can handle a surprising variety of furniture joinery.
