If your treadmill needs a simple adjustment or repair, you’ll likely need to know what size allen wrench for treadmill bolts typically require. This common tool, also called a hex key, is essential for home maintenance, and finding the right size is the first step.
What Size Allen Wrench For Treadmill
Most treadmill manufacturers use metric allen bolts. The most common size you’ll need is a 5mm or 6mm allen wrench. However, it’s not unusual to find 4mm, 8mm, or even 10mm bolts on certain parts. The best way to be sure is to check your owner’s manual, as it will list the exact tools needed for assembly and adjustments.
How to Find the Correct Allen Key Size
Don’t have the manual? Don’t worry. There are a few easy ways to figure it out.
- Check Existing Tools: If you assembled the treadmill yourself, look through the tools that came with it. The correct allen wrench was almost certainly included in the box.
- Use a Multi-key Set: The simplest solution is to buy a set of metric allen keys or a folding multi-tool. You can then test different sizes until you find the one that fits snugly without wobbling.
- Measure the Bolt: If you can access the bolt, use a set of calipers or a metric ruler to measure the distance between two parallel sides of the bolt head. This measurement in millimeters is the allen wrench size you need.
- Contact the Manufacturer: You can often find the manual online by searching your treadmill’s model number. Customer support can also tell you the tool specifications.
Common Treadmill Areas Requiring an Allen Wrench
You’ll use your allen wrench on several key components. Knowing where to look can save you time.
Belt Adjustment and Alignment
This is the most frequent use. The rear roller adjustment bolts are almost always allen bolts. Turning these bolts clockwise or counterclockwise will tighten or loosen the walking belt. The exact size can vary, but 5mm or 6mm are very common here.
Console and Upright Assembly
The bolts that attach the console to the uprights and the uprights to the base frame are typically allen bolts. They are often a bit larger, sometimes 8mm. Be careful not to overtighten these, as you could strip the threads or damage the plastic.
Folding Mechanism Hinge
If you’re treadmill folds for storage, the hinge lock will use a large allen bolt. This bolt needs to be kept tight for safety, but also loosened when you want to fold or unfold the machine. It’s often one of the bigger sizes, like 10mm.
Motor Cover and Side Rails
Removing the motor cover to inspect the drive belt or electronics usually involves several small allen bolts. The side rails that you hold onto might also have allen bolts securing them to the frame.
Step-by-Step Guide for Basic Treadmill Adjustments
Once you have the right tool, here’s how to handle two common tasks.
Adjusting the Walking Belt:
- Unplug the treadmill from the wall outlet for safety.
- Locate the two rear roller adjustment bolts at the back end of the treadmill.
- Insert your allen wrench and turn both bolts a quarter-turn clockwise to tighten the belt if it’s slipping.
- If the belt is pulling to one side, you’ll need to realign it. Turn the bolt on the side the belt is moving toward a quarter-turn clockwise. Turn the opposite side bolt a quarter-turn counter-clockwise.
- Plug the treadmill back in and test at a low speed. Repeat the small adjustments until the belt runs centered and smooth.
Tightening the Frame Bolts:
- Again, always unplug the machine first.
- Listen for squeaks or feel for wobbles as you walk on the treadmill to identify loose joints.
- Systematically check and tighten all visible frame and upright allen bolts. Do not overtighten—just until they are snug.
- This regular check can prevent wear and tear and make your treadmill last longer.
Choosing the Right Type of Allen Wrench
Not all allen wrenches are created equal. Using the right style makes the job easier.
- L-Key Wrenches: These are the standard, inexpensive tools. They offer good leverage but can be hard to use in tight spaces.
- Folding Hex Key Sets: These are very handy for treadmill owners. They keep all the common sizes in one compact tool, and the handle provides better grip than an L-key.
- Socket Driver Bits: If you own a ratchet set, getting a set of metric hex bits is excellent. They allow for fast turning and are great for bolts that need more torque.
- T-Handle Wrenches: These provide the best grip and torque for stubborn bolts. They are a good investment if you plan on doing regular maintenance.
Safety Tips When Working on Your Treadmill
Your safety is the most important thing. Always follow these rules.
- Always Unplug: Never work on a treadmill that is plugged in. This eliminates the risk of electric shock or the motor accidentally starting.
- Clear the Area: Make sure you have plenty of space to work and that the floor is not cluttered.
- Don’t Force It: If a bolt won’t turn, don’t use excessive force. You might strip the head. Apply a penetrating oil like WD-40 and let it sit for 15 minutes before trying again.
- Refer to Manuals: For complex issues, especially involving the electronics or motor, the manufacturer’s guide is your best resource.
- Know Your Limits: If a repair seems beyond your comfort level, it’s okay to call a professional technician. Some things are better left to experts.
FAQ Section
What size allen key for a NordicTrack treadmill?
NordicTrack often uses 5mm and 6mm allen wrenches for belt adjustment and assembly. Always check your specific model’s manual to be certain, as some parts may differ.
What size hex key for a ProForm treadmill?
ProForm, like its sister brand NordicTrack, commonly uses 5mm and 6mm sizes. The tools provided in the box are usually the correct ones for that model.
Can I use an imperial allen wrench on metric treadmill bolts?
You should not. While a similar imperial size might seem to fit, it will not seat properly and will likely strip the bolt head, making future removal very difficult. Always use metric tools for metric bolts.
My treadmill allen wrench is lost, how do I know what to buy?
A metric allen wrench set is your best bet. They are inexpensive and widely available at hardware stores. A set with sizes from 2mm to 10mm will cover almost any treadmill bolt.
Why does my allen wrench keep slipping?
This usually means you are using the wrong size. Double-check the fit. If the size is correct, the bolt head may be worn or stripped from previous use with an incorrect tool.
How often should I check the bolts on my treadmill?
It’s a good habit to check and tighten frame bolts every few months, or whenever you hear new squeaks or feel new vibrations. The constant motion of a treadmill can loosen bolts over time.
Having the correct allen wrench on hand makes basic treadmill maintenance a simple DIY task. By identifying the common sizes, using the right type of tool, and following safety steps, you can keep your machine running smoothly for years to come. Remember, starting with a multi-key set is often the easiest solution for any home gym owner.