The thickness of a saw blade is measured in thousandths of an inch or in millimeters. This measurement, often called the saw blade gauge, tells you how stout the main body of the blade, or the blade plate thickness, actually is.
Why Blade Thickness Matters in Cutting
Saw blade thickness is a very important feature. It directly affects how the blade cuts. A thicker blade might be stronger. A thinner blade removes less material when it cuts. This simple difference changes many things about your sawing work.
The Concept of Blade Kerf Width
When a saw blade spins and cuts wood, it makes a slot. This slot is called the blade kerf width. The kerf is the actual width of the material the blade removes as it moves through the workpiece.
The kerf width is directly related to the blade’s body thickness and how the teeth are shaped.
- Thicker Blade Body: A thicker blade usually means a wider kerf. This uses more power from the saw motor. It also wastes more wood material.
- Thinner Blade Body: A thinner blade makes a narrower kerf. This saves wood and needs less power. However, very thin blades can bend or wobble during hard cuts.
Standard vs. Thin Kerf Saw Blades
Most power tools, like circular saws, are designed for one of two main blade thicknesses. This distinction is crucial for performance and safety.
Standard Saw Blade Thickness
These are the most common blades. They offer a good balance of strength and cutting ability for general use.
- Typical range: Around 0.090 inches to 0.125 inches thick.
- These blades are very stable. They resist bending well, even in tough woods or when making long cuts.
- They work best on saws that have powerful motors.
Thin Kerf Saw Blades
These blades are specifically made to be leaner than standard blades. They are very popular today.
- Typical range: Around 0.071 inches to 0.087 inches thick.
- They use less energy. This is great for battery-powered (cordless) tools.
- They cut faster because they remove less material.
Important Safety Note: You must match the blade thickness to your saw’s design. Using a standard blade on a saw meant for thin kerf saw blades can cause binding or strain the motor. Always check your saw’s manual!
Deciphering the Saw Blade Gauge System
How do manufacturers talk about thickness? They use the saw blade gauge system. This is a numbered scale, much like the one used for wire thickness.
The gauge number tells you the thickness of the main plate. Lower gauge numbers mean a thicker blade. Higher gauge numbers mean a thinner blade.
Saw Blade Gauge Chart Examples
It is helpful to see these numbers compared to actual measurements. The exact standard can vary slightly between tool makers, but this table shows a general idea of the saw blade gauge chart in use for common 10-inch and 7-1/4 inch blades.
| Gauge Number | Approx. Thickness (Inches) | Approx. Thickness (mm) | Common Use |
|---|---|---|---|
| #10 | 0.134″ | 3.40 mm | Heavy Duty/Thickest Plate |
| #12 | 0.104″ | 2.64 mm | Standard Circular Blade |
| #14 | 0.085″ | 2.16 mm | Thin Kerf (TK) |
| #16 | 0.063″ | 1.60 mm | Very Thin/Specialty Blades |
When you look at packaging for a circular saw blade, you often see the thickness listed right next to the diameter and arbor size. For example, a blade might be listed as “7-1/4″ x 24T x 5/8” (0.071″).” That measurement in parentheses is the gauge translated into inches.
Measuring Saw Blade Thickness
To get an exact saw blade thickness measurement, you need the right tools. You cannot accurately use a ruler for this precision work.
- Digital Calipers: These are the best tool. They give readings down to 0.001 inch. Measure the body of the blade, making sure to avoid the teeth tips.
- Micrometer: A blade micrometer is even better for very thin blades, though digital calipers are often sufficient for most users.
When measuring the thickness of circular saw blade, measure the steel plate itself, not the width taken up by the teeth that stick out (the set).
The Role of Tooth Set in Overall Kerf
While the blade plate thickness sets the minimum kerf, the teeth dramatically increase the final cut width. This is where the saw blade tooth set measurement comes into play.
The “set” refers to the slight bend or flare given to the teeth tips. These teeth are bent alternately left and right. This action creates a kerf wider than the blade body itself.
Why Teeth Need Set
- Clearance: The set ensures that the main body of the blade does not rub against the sides of the cut. Rubbing creates massive friction, which causes heat, burns the wood, and slows the saw motor.
- Chip Ejection: The wider path helps the sawdust (chips) clear out of the cut.
How Set Affects the Final Kerf
If you have a blade with a #14 gauge plate (about 0.085 inches thick), but it has a wide set, the total blade kerf width might end up being 0.110 inches.
Formula Approximation:
$$\text{Total Kerf} \approx \text{Blade Plate Thickness} + \text{Total Tooth Set (Left + Right Bend)}$$
For very high-quality blades designed for fine finish work, the set might be minimal to keep the kerf as narrow as possible, matching the blade’s thin gauge.
Material Choice and Blade Thickness
The material the blade is made from also dictates how thin the plate can be safely constructed.
High-Speed Steel (HSS) vs. Carbide-Tipped Blades
Most modern blades use steel cores, often with carbide tips brazed onto the teeth.
- Carbide Tips: These are very hard. They let the blade keep a sharp edge longer. Because the tips do the cutting, the steel body supporting them can be slightly thinner while still providing good support.
- Steel Core: The steel core must be rigid enough to stop vibration. Very thin plates are prone to vibration, especially at high RPMs (rotations per minute).
Considerations for Large Blades (Table Saws, Radial Arms)
On large blades, like those used in cabinet shops (12-inch or 14-inch table saw blades), stability is paramount.
- These blades are often thicker (lower gauge) to prevent bowing across the large span.
- They often feature slots cut into the plate body. These slots are designed to reduce vibration and warping caused by heat expansion, even on thick blades.
Impact of Blade Thickness on Saw Types
Different tools require different blade specifications based on their power and typical use.
1. Handheld Circular Saws (7-1/4 inch Blades)
This is where the standard vs. thin kerf debate is most active.
- Cordless saws strongly favor thin kerf saw blades (around 0.068″ to 0.071″). This extends battery life significantly.
- Corded saws, especially older or heavy-duty models, often perform better with standard thickness blades for maximum durability in framing lumber.
2. Table Saws (10-inch Blades)
Table saws are used for precision ripping (cutting with the grain) and cross-cutting (cutting across the grain).
- Ripping Blades: Often have fewer teeth and are designed to clear material quickly. They might use a standard gauge for rigidity when ripping long boards.
- Finishing Blades: These have many teeth and are designed for very smooth cuts. They may use slightly thinner plates to reduce the force needed to push the small teeth through the material, which helps prevent tear-out.
3. Miter Saws (Chop Saws)
Miter saws usually demand high accuracy. While they use standard sizes (10-inch or 12-inch), vibration control is key.
- Many high-end miter saw blades feature anti-vibration slots precisely to keep a mid-range blade plate thickness stable during fast, powerful cuts.
Technical Details: Blade Arbor Hole Size
While not directly about thickness, the blade arbor hole size is a critical specification that must match the saw’s spindle exactly. If the arbor hole is too loose, the blade wobbles, which is dangerous and ruins the cut quality, regardless of the blade’s thickness.
Common arbor sizes include 5/8 inch, 1/2 inch, and sometimes proprietary sizes. Always verify this when purchasing a replacement blade.
Fathoming Performance Differences Based on Thickness
Choosing the right thickness involves trading off power consumption, speed, cut quality, and tool longevity.
Power Use
A thicker blade requires the motor to do more work against friction and inertia.
- Thick Blade: Consumes more amperage (draws more power). Can bog down a weaker saw motor.
- Thin Blade: Consumes less power. Ideal for maximizing runtime on battery tools.
Cut Quality and Heat
Heat is the enemy of a clean cut. Friction generates heat, which causes the wood to scorch and the blade to warp.
- A standard blade, if used in a saw underpowered for its size, can run very hot.
- A thin kerf blade, when run correctly, generates less friction heat because it removes less wood mass overall. This usually results in a cooler, cleaner cut, provided the blade doesn’t flex.
Stability and Vibration
This is the main reason why extremely thin blades are not universally adopted.
- Thin Blades: More prone to lateral flexing. If you push them too hard, they can wander slightly off the line, leading to an inaccurate cut. This is why thin kerf blades are typically not recommended for heavy-duty construction framing where immense force is applied.
- Thick Blades: Inherently more rigid. They resist flexing, ensuring the cut stays straight even under heavy load.
When Should You Choose a Thin Kerf Blade?
The move toward thinner blades is driven by efficiency and portability.
- Cordless Saws: If your saw runs on batteries, a thin kerf blade is almost always the best choice to maximize cutting time between charges.
- Soft Materials: When cutting plywood, MDF, or softwood, the reduced material removal rate of a thin kerf blade helps maintain speed.
- Ripping Long Boards: When making long, straight cuts (ripping), saving power and reducing friction becomes more important than the extreme rigidity needed for thick hardwood cross-cuts.
When to Stick with Standard Blade Thickness
There are specific applications where the added rigidity of a standard gauge blade is non-negotiable.
- Hardwoods: Cutting dense woods like oak, maple, or exotic hardwoods puts extreme stress on the blade plate. A standard gauge resists the side pressure better.
- Plunge Cuts or Non-Through Cuts: If you frequently start a cut in the middle of a panel (a plunge cut), the blade must resist deflection when it first enters the material.
- Heavy-Duty Corded Saws: Saws with large, powerful motors can handle the slightly higher load of a thicker blade, and benefit from the stability it provides.
Final Thoughts on Blade Gauge Selection
Selecting the correct blade thickness involves matching the tool to the task. Do not just grab the cheapest or most common blade. Check your saw’s specifications first to determine if it requires a standard or a thin kerf saw blades.
Consulting a blade gauge chart before purchasing can help you translate the manufacturer’s technical specification into a practical choice for the wood you are cutting. Remember, a well-matched blade thickness ensures safety, efficiency, and superior finish quality in your woodworking projects.
Frequently Asked Questions (FAQ)
Q: Can I use a standard thickness blade on a thin kerf saw?
A: Generally, no. While the blade arbor hole size might match, using a standard blade on a saw designed for thin kerf blades can cause the thicker blade body to bind or rub against the saw’s base plate or fence. This creates excessive heat and strain on the motor, which can damage the tool or cause a dangerous kickback.
Q: Does the tooth count affect the blade thickness or gauge?
A: No. The tooth count (e.g., 40T or 60T) relates to the number of cutting edges around the circumference. The saw blade gauge refers strictly to the thickness of the main steel plate supporting those teeth. However, a blade with many teeth (high tooth count) usually requires a thinner kerf to allow for proper tooth set and chip clearance.
Q: What is the thickest part of a circular saw blade?
A: The thickest part is the main body, or the blade plate thickness. The teeth themselves stick out beyond this measurement due to the set. When discussing the saw blade thickness measurement, we are usually referring to the plate thickness before the set is added.
Q: How do I know what blade thickness my saw needs?
A: Always check the owner’s manual for your saw. Manufacturers clearly specify if the tool requires a standard blade (usually listed as the standard kerf width) or a thin kerf blade (TK). If the manual is unavailable, look closely at the blade currently used in the saw or check the decal near the blade guard.