Most woodworkers learn a simple rule: more teeth equals smoother cuts, fewer teeth equals faster cuts. This oversimplification sends countless makers to the store with nothing but tooth count in mind, only to wonder why their 80-tooth blade still tears out maple or why their rip cuts burn despite using a dedicated ripping blade.

The reality is that tooth count represents just one variable in a complex geometry that determines how a blade interacts with wood. Hook angle, rake, grind pattern, and gullet size each contribute independently to cutting action, chip clearance, and surface quality. Understanding these variables transforms blade selection from guesswork into informed decision-making.

This isn't about memorizing specifications. It's about developing the kind of geometric intuition that lets you look at a blade, understand its design intent, and predict how it will behave in different materials and cut orientations. Once you grasp these principles, you'll never blindly trust tooth count recommendations again.

The hook angle—the forward lean of each tooth relative to the blade's radius—determines cutting aggression more than any other single factor. A positive hook angle means teeth lean forward, pulling themselves into the material and taking larger bites. A negative hook angle means teeth lean backward, requiring more feed pressure but offering more control and less tearout.

Most general-purpose blades run 15-20 degrees positive hook for a balance of cutting speed and reasonable surface quality. Dedicated ripping blades push to 20-25 degrees for aggressive material removal. Melamine and crosscut blades often use 5-10 degrees or even negative hooks to prevent the grabbing action that causes chipout on brittle surfaces.

Top grind patterns affect how teeth sever wood fibers. Alternate Top Bevel (ATB) grinds create knife-like points that slice fibers cleanly—ideal for crosscuts where you're severing end grain. Flat Top Grind (FTG) works like tiny chisels, efficient for rip cuts where you're splitting fibers apart. Combination grinds attempt both, with mixed results.

Gullet size—the valley between teeth—determines chip clearance capacity. Deep gullets accommodate the long shavings produced in rip cuts. Shallow gullets on high-tooth-count blades are fine for crosscuts where chips are small, but they clog disastrously in rip cuts, generating friction heat that burns wood and damages blades.

Takeaway

Hook angle determines aggression, grind pattern determines fiber separation method, and gullet size determines chip clearance. Tooth count merely tells you how many cutting events occur per inch—not how each cut actually happens.

Softwoods and hardwoods demand different blade characteristics, but not always in the ways you'd expect. Softwoods are grabby—their fibers separate easily, which sounds like an advantage but creates problems. A high positive hook in soft pine can cause the blade to self-feed aggressively, leading to rough cuts and potential kickback. Moderate hook angles with ATB grinds give cleaner results.

Hardwoods resist penetration but cut more predictably once you're through the surface. They can handle aggressive hook angles without grabbing, and their density means fibers sever rather than tear. Dense exotics often benefit from the same blade profiles used for plywood and melamine—lower hooks and high tooth counts that prioritize controlled, clean cutting over speed.

Cut direction matters as much as species. Rip cuts, traveling parallel to grain, work like splitting kindling—you're separating fibers along their length. This demands aggressive geometry, deep gullets, and fewer teeth. Crosscuts sever fibers perpendicular to their length, requiring many small cuts with slicing geometry to prevent the fibers from tearing out ahead of the cut.

Finished surface requirements should influence your selection. If you're rough-cutting parts to be jointed and planed, there's no point sacrificing speed for surface quality. If you're cutting to final dimension on a sled, that same rough blade will cost you hours of sanding. Match blade capability to actual requirements, not theoretical ideals.

Takeaway

Think in terms of fiber behavior: will you separate fibers or sever them? Is the material likely to grab or resist? Match blade geometry to these mechanical realities rather than relying on generic tooth count recommendations.

A dull premium blade outperforms a sharp budget blade briefly, then performance collapses. Carbide tips don't gradually dull—they chip and fracture, creating localized dead spots that cause inconsistent cutting pressure across the blade. This uneven loading accelerates wear on remaining sharp teeth, creating a cascade of degradation.

The first sign of blade fatigue isn't usually visual. It's increased feed resistance, followed by burning, then tearout that persists regardless of feed rate. By the time you see visible damage to carbide tips, the blade has been underperforming for many cuts. Learn to read the indirect signs: if you're pushing harder for the same results, the blade needs attention.

Professional sharpening makes economic sense for quality blades with substantial carbide—typically those costing $80 or more new. Budget blades often have thin carbide brazing that can't survive multiple sharpenings, making replacement the smarter choice. A $120 blade that survives five sharpenings at $20 each costs $220 over its lifetime but performs like a $120 blade. A $40 blade replaced five times costs $200 but performs like a $40 blade.

Keep dedicated blades for dedicated purposes. A combination blade used for everything dulls across all its geometry simultaneously. Separate ripping and crosscut blades allow you to optimize each for its specific task and extend time between sharpenings by reducing inappropriate use. This also lets you identify which operations consume blade life fastest.

Takeaway

Track performance, not just visible damage. When a blade starts requiring more effort for the same result, it's already compromising quality—whether or not the carbide looks worn. Economics favor sharpening premium blades and replacing budget ones.

Blade selection becomes intuitive once you understand what each geometric variable contributes. Hook angle controls aggression, grind pattern determines how fibers are severed, gullet size manages chip evacuation, and tooth count simply divides these effects across the cutting circle.

The next time you're choosing a blade, think mechanically. Consider whether you're severing or splitting fibers, whether the material grabs or resists, and what surface quality you actually need. Then select geometry that matches those demands.

Good blades are investments that reward understanding. A craftsman who knows why a blade performs gets more value from every tool than one who follows rules they don't understand.