When using a circular saw to cut a piece of plywood, where should the cut line be relative to the saw blade?

KERF is the slot left by a saw blade, equal to the blade thickness (typically 1/16 inch to 1/8 inch for circular saw blades). Material is removed; you must account for it. STANDARD PRACTICE: position the blade so it cuts on the WASTE SIDE of your marked line, meaning the kerf is removed from the part you don't want, and the line itself remains on the piece you're keeping. This produces an accurate final piece. POWERED SAW BLADE has teeth wider than the blade body (called the SET) to prevent binding. CIRCULAR SAW USE: measure twice, cut once is the old carpentry maxim; mark cut line clearly with pencil or knife; use a straightedge or guide or rip fence for accurate straight cuts; set BLADE DEPTH only slightly deeper than material (less binding, less danger, less splintering of underside); use sharp blade with appropriate TPI for material; plywood is best cut with fine-tooth blade (40-60 teeth, no tear-out) and from the GOOD side DOWN (blade cuts up through bottom, tear-out on top is invisible side); support both sides of cut (workpiece should fall away cleanly, not pinch the blade — pinched blade causes KICKBACK where saw violently flies back at operator); use saw horses with proper support; wait for blade to reach full speed before cutting; allow blade to STOP before lifting saw away. KICKBACK CAUSES: blade pinching in cut (warped wood, unsupported offcut); blade striking foreign object; binding in dense material; dull blade; cutting curves. AVOID kickback by proper workpiece support, sharp blades, correct blade type, never standing in line with possible kickback path. PPE: eye protection (safety glasses or face shield); hearing protection (saws are loud, 100+ dB); dust mask especially for plywood/MDF (formaldehyde and silica); no loose clothing or jewelry; gloves NOT recommended for spinning tools because they can be grabbed. MEASURING AND CUTTING: tape measure marks length; square marks perpendicular cut lines; for angled cuts use a protractor or combination square; laser guides on modern saws help align cuts. RIPPING (cut parallel to grain) vs CROSS-CUTTING (cut across grain): different blade types optimal; combination blades are general-purpose. CIRCULAR SAW SIZE: 7-1/4 inch most common for general carpentry; can cut up to about 2-1/2 inches deep at 90 degrees; cordless options widely available; corded provides more power for heavy work. WORM-DRIVE saws have more torque; SIDEWINDER (standard) saws are lighter, faster blade speed.