A table saw fence is a long, straight guide that runs parallel to the saw blade. Its main job is to hold your wood firmly in place. This keeps the wood moving straight across the spinning blade. A good fence is vital for making accurate, safe cuts every single time you use your table saw.
The Core Function of a Table Saw Fence
The table saw is often called the heart of the woodworking shop. It can do many cuts. Ripping (cutting wood along its length) is one of the most common tasks. For ripping to work well, the wood must stay perfectly straight. This is where the fence comes in.
The fence acts as a reference point. You set the distance between the blade and the fence. This distance tells the saw exactly how wide your board will be after the cut. Without a reliable fence, your rip cuts will be uneven, angled, or even dangerous.
Safety First: How the Fence Protects You
Safety is the biggest reason why the fence matters so much. When wood binds or pinches the blade, kickback can happen. Kickback is when the saw violently throws the wood back toward the operator.
A properly set and locked fence prevents this problem. It keeps the wood moving forward smoothly. It stops the wood from twisting toward the back of the blade. A loose or inaccurate fence for table saw work is a major safety hazard.
Accuracy and Repeatability: The Woodworker’s Goal
Woodworkers need cuts that match. If you need ten pieces of wood exactly 6 inches wide, they must all be identical. This is called repeatability.
A high-quality fence allows for precise setup. You move the fence to the exact measurement you need. Then, you lock it down tight. When the next piece is cut, it will be the same size. This saves huge amounts of time and material.
Different Kinds of Table Saw Fences
Not all fences are built the same. The quality of the fence greatly affects how easy it is to use and how precise your cuts are. Let’s look at common table saw fence types.
1. Biesemeyer Style Fences
These fences are famous in the woodworking world. They are often seen on professional saws. They use a clamping mechanism that locks the fence down both at the front and back of the table simultaneously.
- Pros: Excellent accuracy. Very rigid. Easy to adjust quickly.
- Cons: Can be expensive to buy new or upgrade to. Sometimes heavy.
2. T-Square Fences
This style is very common on mid-range and contractor saws. They use a single locking handle, often at the front of the saw. When you unlock it, the fence slides smoothly. When you lock it, a mechanism squares it up to the blade.
- Pros: Simple design. Generally easier to operate than older designs.
- Cons: Can sometimes lose squareness if not locked perfectly. Not always as rigid as Biesemeyer styles.
3. Old or Basic Fences (Often Included with Entry-Level Saws)
Many beginner or older saws come with very basic metal bars. These often rely on knobs or bolts to lock them in place.
- Pros: Cheap if they come with the saw.
- Cons: Prone to deflection (bending in the middle). Hard to set perfectly square. Measurements often drift when locking. This leads to poor table saw fence accuracy.
4. Aftermarket and Premium Fences
Many woodworkers buy new fences for older or less capable saws. These best table saw fence systems often offer major improvements in rigidity and ease of use.
- They use better bearing systems.
- They feature digital readouts for extreme precision.
- They are built from thicker, stronger aluminum.
Setting Up for Success: Adjusting a Table Saw Fence
Even the best fence needs correct setup. Adjusting a table saw fence involves two main steps: setting the distance and ensuring it is parallel to the blade (squaring it).
Step 1: Setting the Cut Width
This is the easy part. You look at the measurement scale built into the fence rails. You move the fence until the scale reads the desired width. Always check your measurement with a tape measure or calipers for critical cuts. Scales can sometimes be slightly off from the factory.
Step 2: Squaring the Fence to the Blade (Crucial Step)
This step prevents binding and kickback. The fence must be perfectly parallel to the line of the teeth on the blade. If the fence is angled inward (toward the back of the blade), the wood will be squeezed between the fence and the blade as you push it through. This causes burning, binding, and danger.
How to Check for Squareness:
- Measure at the Front: Measure the distance from the blade to the fence, right at the front edge of the saw table.
- Measure at the Back: Measure the distance from the blade to the fence, right at the back edge of the saw table.
For a perfect rip, these two measurements should be the same. However, for safety, many pros recommend setting the fence slightly further away from the blade at the back. This slight flare ensures the wood exits freely.
- Example: If the front gap is 8 inches, the back gap should be 8 inches or maybe 8 and 1/16th of an inch. Never let the back gap be smaller than the front gap.
Dealing with Fence Deflection
If you have a long fence or a long board, the middle of the fence might bow slightly, even when locked down. This is deflection.
- Check: Push gently on the middle of the fence while it is locked. If it moves away from the blade, you have deflection.
- Fix: Better fences have adjustable struts or braces to eliminate this. For cheaper fences, you might need to use a separate, heavy outfeed table support near the back to keep the fence straight during long rips.
Comparing Fences: Table Saw vs. Router Table
It is important to know the difference between a router table fence vs table saw fence. While both guide wood, their requirements are different.
| Feature | Table Saw Fence | Router Table Fence |
|---|---|---|
| Primary Use | Ripping long boards to width. | Shaping edges, dadoes, or rabbets. |
| Movement | Moves in and out across the blade. | Stays fixed while the router bit spins. |
| Dust Collection | Often less integrated; requires add-ons. | Usually has a built-in port for chips. |
| Crucial Need | Extreme rigidity and perfect squareness. | Ability to adjust depth and have two independent faces. |
The router table fence often has two adjustable faces. This lets you set a gap for the protruding router bit, which is essential for certain cuts like trimming laminate or making rabbets. The table saw fence only guides the material laterally.
Upgrading Your Setup: Why and How to Improve Your Fence
If you own an older saw, or if your stock fence is wobbly, upgrading table saw fence systems is one of the best investments you can make. A better fence directly improves safety, speed, and accuracy.
Reasons to Upgrade
- Accuracy: Modern fences guarantee near-perfect parallelism.
- Ease of Use: They lock instantly and reliably with one hand.
- Rigidity: They do not flex or move when pushed hard against thick material.
- Capacity: Premium fences often extend further from the blade, allowing you to rip very wide panels accurately.
Popular Upgrade Paths
Many manufacturers sell bolt-on replacement systems. These fit the existing holes on many popular saw cabinets.
When shopping for an upgrade, look closely at:
- How it locks (cam locks are often preferred).
- The quality of the scale (etched aluminum is better than stickers).
- How easy it is to adjust the fence faces if they wear down or get nicked.
Building Your Own Solution: DIY Table Saw Fence
For hobbyists or those on a tight budget, a DIY table saw fence can be a great project. The goal is to replicate the best features of commercial fences using common materials.
The biggest challenge in DIY is achieving true parallelism and rigidity without expensive parts.
Essential DIY Components
- The Fence Bar: Needs to be perfectly straight. Look for thick, extruded aluminum T-track or heavy, flat steel bar stock. Wood is generally discouraged unless very well braced, as it can warp.
- The Rails: These must be securely mounted to the saw table and perfectly straight. Angle iron or heavy steel tubing works well.
- The Locking Mechanism: This is the hardest part. You must achieve high clamping force across the entire length. A common DIY method involves using large bolts or cam levers that pull the fence tight against stops mounted on the rails.
A successful DIY fence must be strong enough that heavy pressure does not cause it to move away from the blade. Test rigorously before trusting it with expensive lumber.
Advanced Fence Concepts and Features
Modern fences offer specialized features that go beyond simple ripping.
Zero Clearance Inserts and Fences
A zero clearance table saw fence is not common. Usually, the term applies to the blade insert plate (which supports wood right next to the blade teeth). However, when discussing fences, sometimes users want a fence that can get extremely close to the blade without interference, which aids in cutting small pieces safely next to the fence.
For very thin strips (less than 1 inch wide), specialized featherboards that clamp to the table surface might be used in conjunction with the fence to provide guiding pressure.
Featherboards and Fence Use
Featherboards are essential helpers, especially when working with thin stock or non-standard materials.
- Function: They have flexible plastic or wooden “feathers” that press against the side of the wood.
- Benefit: They hold the wood tight against the fence even if the wood itself is slightly warped or floppy. This adds an extra layer of safety and accuracy, acting like a continuous, compliant pressure mechanism along the fence line.
Magnetic Table Saw Fence Systems
Some high-end or specialized setups use magnetic components. A magnetic table saw fence might use powerful magnets embedded in the fence body and the table surface. When engaged, these magnets help lock the fence in position, often supplementing a mechanical lock. This can reduce slippage caused by vibration or slight twisting forces. They are generally found in specialized, modern industrial machinery rather than standard consumer models.
Maintenance for Maximum Fence Performance
A table saw fence is a precision instrument. It requires care to stay accurate.
Cleaning the Rails and Fence Faces
Sawdust, dried glue, and pitch build up quickly on the rails where the fence slides. This buildup causes sticking, inaccurate readings, and difficulty locking the fence.
- Action: Regularly clean the rails with a plastic scraper or a shop vacuum. A little paste wax on the rails can help the fence slide smoother, but ensure it doesn’t attract excessive dust.
Checking the Scale Alignment
If your fence scale is just a decal or painted line, it can easily be knocked out of alignment during heavy use or transport.
- Action: Periodically re-verify your fence scale against a known good measurement tool. If the scale does not match the physical measurement, either correct the scale position (if possible) or rely only on a measuring tape held against the blade.
Lubrication
Check your fence system’s manual. Some sliding mechanisms benefit from dry graphite lubricant or specific rail grease. Never use heavy oil, as this will attract and hold debris, gumming up the works quickly.
Factors Influencing Fence Performance
Several factors outside the fence itself can impact its effectiveness.
The Saw Table Surface
If the table surface is warped, nicked, or coated in residue, the fence rails mounted on top will also be compromised. A clean, flat table is the foundation for an accurate fence.
Outfeed Support
When ripping long boards, the weight of the wood pulling away from the saw can cause the tail end of the fence to lift or tilt slightly. This shifts the measurement at the back.
- Solution: Always use roller stands or an outfeed table when ripping boards longer than the depth of your saw table. This support keeps the wood level and reduces strain on the fence mechanism.
Material Properties
Softwoods like pine often compress slightly when clamped tightly, which can temporarily reduce the cut width if the fence is too tight. Hardwoods are more stable. Knowing your material helps you decide how tightly to set your fence pressure without causing binding.
Frequently Asked Questions (FAQ)
Q1: Can I use a router table fence on my table saw?
No, you should not try to use a standard router table fence vs table saw fence setup directly. Router fences are often designed to be adjusted only at the front face, and they typically lack the rigidity needed to handle the side thrust created by a spinning table saw blade ripping through thick wood.
Q2: How tight should I lock my table saw fence?
The fence must be locked tightly enough that it cannot move when the wood is pushed hard against it. There should be zero wobble or play. If you can wiggle the fence by hand after locking it, it is not tight enough for a safe, accurate cut.
Q3: My fence scale says 8 inches, but my board measures 7 7/8 inches. Why?
This is a common issue related to table saw fence accuracy and setup. There are two main reasons:
1. The scale is slightly misaligned.
2. The fence is slightly angled toward the back of the blade (zero clearance setup is wrong).
Always trust your measuring tape or calipers over the fence’s built-in scale for critical measurements.
Q4: What should I do if my fence is too short to rip wide boards?
If your current fence is too short, you can often attach an extension—usually a piece of straight wood or MDF—to the fence face. This extension must be glued or screwed firmly to the main fence body to ensure it moves as one solid unit and remains square.
Q5: Are magnetic fences always better than mechanical ones?
Not necessarily. Magnetic systems provide great rigidity but are often complex and expensive. For most home shops, a high-quality mechanical system (like a good Biesemeyer style) offers the best balance of accuracy, rigidity, and cost-effectiveness.
The table saw fence is far more than just a sliding metal bar. It is the primary tool for dimensional accuracy and a critical safety feature. Investing time in selecting, setting up, and maintaining your fence directly translates into better woodworking results and a safer shop environment. From basic alignment checks to considering a full upgrading table saw fence system, giving the fence the attention it deserves is key to mastering the table saw.