Craftsman 315108340 circular saw Parts

A 140-tooth circular saw blade is a fine-finish blade used for smooth, low-tearout cuts in thin sheet goods and trim. On your Craftsman 315108340 (7-1/4 inch blade), it is best for plywood and similar panels when you want minimal chipping and a cleaner edge; see the owner's manual for blade size and safe operation details.

Best uses for a 140-tooth blade

A high tooth count means smaller bites per tooth, which improves finish quality but slows cutting.

• Plywood and veneered panels (cleaner top surface)
• Melamine and laminated shelving (reduced edge chipping)
• Thin hardwood trim and molding (smoother cut face)
• Masonite and other thin fiber panels
• Some plastics (use light feed pressure and support the work)

When not to use it

A 140-tooth blade is not the right choice for fast, heavy cuts.

• Thick framing lumber (2x material) where speed matters
• Wet, pitchy, or dirty wood that gums up teeth quickly
• Aggressive ripping with the grain (higher kickback risk if you force the cut)

Quick selection guide

Blade type	Typical tooth count	Best for
Fine finish	100 to 140+	Plywood, laminates, trim
General purpose	24 to 60	Mixed cuts in lumber and sheet goods
Rip	18 to 24	Fast cuts with the grain

Why it matters

Using the right blade reduces splintering and helps the saw cut with less strain. The manual also notes that dull or dirty blades cut poorly and increase kickback risk; keep blades clean and sharp, and avoid forcing the saw through the cut.

Last updated: February 2026

If your Craftsman 315108340 circular saw stops mid-cut, the most common causes are voltage drop (long/undersized extension cord), a dull or dirty blade that overloads the motor, or cutting technique that forces the saw and triggers a power loss. Start by confirming a solid 120V AC supply and using a sharp, clean blade.

Quick checks that fix most mid-cut stoppages

• Plug the saw directly into a known-good outlet; avoid power strips.
• If you must use an extension cord, use a short, heavy-gauge cord (long cords cause voltage drop).
• Let the blade reach full speed before contacting the wood.
• Use steady, even feed pressure; do not force the cut.
• Check the blade for pitch buildup and dull teeth; clean or replace as needed.
• Verify the blade is installed correctly and tightened securely.

What the manual points to (and why it matters)

Your saw is designed for 120 volts, 60 Hz, AC only. The manual explains that a substantial voltage drop causes loss of power and can overheat the motor. It also notes that a dull blade places a heavy load on the saw and increases kickback risk. Review the operating and safety guidance in the 315108340 owner's manual.

Symptom-to-cause guide

What you notice	Most likely cause	What to do next
Stops only when the cut gets “heavy”	Dull/dirty blade, forcing the saw	Clean blade, swap to a sharp blade, slow feed rate
Stops more with an extension cord	Voltage drop	Shorten cord, use heavier gauge, try direct outlet
Stops randomly, restarts when you release and pull trigger	Switch trigger or internal electrical issue	Inspect cord/plug, stop using if intermittent, have it serviced
Bogging plus burning smell	Overload/overheating	Stop, let cool, correct blade and cutting technique

Why it matters

A saw that repeatedly stalls is usually being overloaded. That increases heat in the motor and raises the chance of kickback. Using a sharp blade, proper feed pressure, and a solid power supply keeps cuts straighter and protects the switch, cord, and motor.

Last updated: February 2026

On the Craftsman 315108340 circular saw, the bottom plate that rides on the workpiece is commonly called the base (also called the shoe). It supports the saw during a cut and works with the depth-of-cut and bevel adjustments.

What you will see it called on this model

In Craftsman documentation for model 315108340, the term base is used in the feature callouts (for example, the depth-of-cut adjustment is shown at the base area). For diagrams and operating features, use the 315108340 owner's manual.

What the base (shoe) does

• Rests flat on lumber, plywood, and paneling to stabilize the saw
• Helps you guide a straight cut along a layout line
• Pivots for bevel cuts (tilted cuts) when you adjust the bevel mechanism
• Works with the depth-of-cut adjustment so the blade is set correctly
• Helps reduce binding and kickback risk when used with proper blade depth

Common names you may hear (quick reference)

Name	Meaning	Most common use
Base	The bottom plate that rides on the material	Manuals, parts diagrams, repair talk
Shoe	Same part as the base	Jobsite slang, how-to guides
Footplate	Same part as the base	Some brands and tool descriptions

Why it matters

Using the right term helps when you are troubleshooting cut accuracy (wandering cuts, bevel not holding) or looking up adjustments like bevel angle and depth-of-cut. It also helps you match the correct diagram when identifying nearby parts like the lower blade guard, bevel adjustment, and depth adjustment.

Last updated: February 2026

If your Craftsman circular saw model 315108340 isn’t spinning, the most common causes are a power supply problem, a trigger switch issue, worn motor brushes, or a jammed blade or guard. Start with the outlet and cord, then move to the switch and motor components.

Quick checks first (fastest fixes)

• Confirm the saw is plugged into a working 120V AC outlet (try a different outlet).
• If you’re using an extension cord, replace it if it’s nicked, loose, or warm to the touch.
• Remove the blade and make sure the arbor turns freely by hand (with the saw unplugged).
• Check the lower blade guard; if it returns slowly or sticks, don’t run the saw until it’s repaired.
• Reinstall a sharp, clean blade; a dull, pitch-covered blade can overload the motor and make it seem like it “won’t spin.”

Likely causes and what to look for

Power supply or cord issue

A voltage drop can reduce power and overheat the motor. If the saw does nothing when you pull the trigger, verify power first.

Trigger switch problem

If the trigger feels loose, intermittent, or the saw only runs when you wiggle the handle, the switch or internal connections can be failing.

Worn motor brushes (common on older saws)

Motor brushes carry current to the spinning armature. When they wear down or burn, the motor may not start, may start and stop, or may run weakly.

Blade or guard binding

A bent blade, debris in the guard area, or a sluggish lower guard can physically prevent the blade from spinning freely.

Troubleshooting guide (symptom to next step)

What you see	Most likely issue	What we do next
No sound at all	Outlet, cord, switch	Verify outlet, inspect cord, then test switch/brushes
Hums but won’t spin	Binding blade/guard, weak brushes	Remove blade, check free spin, inspect brushes
Runs then stops	Brushes overheating, loose wiring	Inspect brushes and internal connections

Why it matters

A saw that won’t spin is often a simple power or wear item issue, but forcing it can overheat the motor or create unsafe cutting conditions. Keeping the blade sharp and the guard moving freely also reduces kickback risk.

For model-specific diagrams, specs (12 amps, 7-1/4 inch blade, 5,000 RPM no-load), and the repair parts list, use the owner's manual.

Last updated: February 2026