This project and the methods demonstrated were built and tested by Rob from Make Things.
In this video, Rob shares three reliable ways to make wooden knobs in the shop—each with its own pros, cons, and use cases. He even runs a real-world strength test to see how they perform under load.
These techniques give woodworkers more control over hardware fit, thread type, and knob size, all while avoiding the limitations of plastic multipacks. Whether you’re building jigs, fixtures, or shop tools, custom knobs can offer better performance with a personal touch.
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Why Make Your Own Knobs?
Off-the-shelf knobs work fine for some tasks, but they come with limitations. They’re often sold in bulk with fixed bolt lengths and a single thread pitch, which might not match your project.
By making knobs in the shop, Rob shows how to size them exactly to your hand, use bolts and threads you already have, and choose materials that suit the application. For high-torque clamping or tight spaces, being able to shape your own knob is a major advantage.
The Problem with T-Nuts
T-nuts are a common choice for adding threads to wooden knobs, but they have weaknesses. They’re designed to be pulled tight from one direction only. If the orientation is wrong or the knob is used frequently, the T-nut can eventually pull loose.
They also require extra care during installation—holes must be drilled accurately, prongs tapped in gently, and sometimes epoxy is needed to hold them in place. That adds time and complexity, especially if you’re making several knobs in a batch.
While T-nuts still have their place, Rob prefers options with better mechanical hold and faster assembly.
Option 1: Lap Joint with Captive Square Nut
Rob’s go-to method for long-lasting, high-strength knobs involves sandwiching a square nut inside a lap joint. The two pieces of wood are glued together with a precisely sized cavity that traps the nut and keeps it from rotating.
Square nuts work better than hex nuts in this case because their shape naturally resists twisting. With fewer sides, a square nut has more bite when confined in a matching recess, giving it excellent strength under load.
This technique is perfect for handles, vises, or shop jigs that require repeatable torque. Once glued, the knob is shaped as needed—whether round, hex, or custom-cut for your hand.
Pros:
- Excellent resistance to torque
- No need for epoxy
- Works with any thread size or pitch
Cons:
- Requires careful layout and glue-up
- Takes a bit more time than other methods
Option 2: Threaded Inserts
Threaded inserts are the fastest method Rob uses. These metal sleeves screw directly into a wooden knob and allow a bolt to be threaded in. They’re easy to install—just drill a pilot hole and drive the insert into place.
Rob recommends using inserts with deep, aggressive threads. Shallow-threaded or hammer-in inserts tend to pull out under heavy use.
To keep them aligned, Rob demonstrates a trick using a drill press and a cut-down wrench bit held in a chuck. This keeps the insert square to the wood and makes installation smoother.
Pros:
- Fastest to install
- No glue required
- Can be used with any bolt
Cons:
- Can pull out under high load
- Not ideal for soft wood or narrow knobs
Plastic Knobs: Quick But Limiting
Plastic knobs sold in packs are convenient—but often too limited. They usually include bolts of preset lengths and a single thread type. If the bolt doesn’t fit your fixture, you may be forced to buy another entire pack.
These knobs are fine for general use, but they restrict your ability to size the grip or bolt length to your needs. For custom jigs or heavy-duty applications, shop-made knobs offer a better solution.
Strength Test: Which One Holds Up Best?
Rob puts the three methods to the test in his shop. He bolts each knob setup into a fixture, then applies force until something breaks.
- T-nut: Surprising strength. In this test, the bolt itself broke before the T-nut pulled out. Still, orientation and installation matter.
- Lap-joint square nut: Extremely strong. Like the T-nut, it held so well the bolt broke under pressure.
- Threaded insert: Pulled out under high load. Still suitable for many uses, but not for heavy torque.
These results confirm that when maximum holding power is needed, a square nut in a lap joint is hard to beat. Threaded inserts are best for quick knobs or light-duty use.
Choosing the Right Approach
- High-torque clamping or heavy-duty jigs: Use the lap joint with captive square nut.
- Quick builds and low-torque adjustments: Threaded inserts work great.
- General-purpose knobs: Plastic knobs are fine, but can be wasteful if the included hardware doesn’t match your needs.
- T-nuts: Only use when properly oriented and securely installed.
Bonus Tips
Rob shares several tips for better knob making:
- Trim a wrench or use an adapter to install threaded inserts quickly with a drill.
- Use a Forstner bit to drill a pocket for square nuts, then chisel to refine the shape.
- Create jigs for repeatable placement if making several knobs.
- Pre-drill all holes and test fit hardware before final glue-up or shaping.
Final Thoughts
Making wooden knobs in the shop gives you total control over design, hardware, and feel. Rob’s video shows that small upgrades like these can improve tool function and workflow.
Want to start simple? Try making one with a threaded insert for practice. Then scale up to a lap-joint knob for something that demands strength. The process is easy to learn—and hard to go back from once you’ve felt the difference.
Support Rob by visiting his site: https://makethingswithrob.com/.