Circular saw selection is governed by three coupled numbers — blade OD, arbor bore, and kerf width — and by tooth geometry matched to the workpiece; diameter sets maximum cut depth at roughly (D − arbor flange)/2, so a 7-1/4 in (184 mm) blade on a corded framing saw delivers about 2-1/2 in (63 mm) of cut at 90°.
Body and tooth material define the application envelope: TCT (tungsten-carbide-tipped) and cermet dominate wood, aluminium and general metal cutting, while PCD-tipped blades are reserved for abrasive composites and laminates where HSS and TCT wear out fast [S2]. For a deeper look at field-duty saw selection, see the spec cut on power-generation field work.
Blade Diameter, Bore and Maximum Cut Depth
Corded framing circular saws are built around three diameters — 7-1/4 in (184 mm), 8-1/4 in (210 mm) and 10-1/4 in (260 mm) — and depth of cut at 90° scales almost linearly with diameter: roughly 2-1/2 in, 2-7/8 in and 3-13/16 in respectively, dropping about 30–35% at a 45° bevel. The bore must match the tool arbor; 5/8 in is the dominant US framing-saw bore, while 30 mm is standard on most European metalworking cold saws, with 1 in and 40 mm bores common on larger industrial heads. [S1]
Tooth count per diameter is the second sizing lever. Wood-rip blades run 24T on a 10 in head; crosscut and finish blades climb to 60T, 80T and beyond; metal-cutting cold saws land at 60–80T for thin-wall tube and 100T+ for thin sheet. The trade-off is feed rate vs finish: doubling tooth count roughly halves the chip load per tooth at constant feed, so a 24T blade takes a 0.015 in chip and an 80T blade a 0.004 in chip on the same diameter at the same fpm [S2].
Tooth Geometry: ATB, TCG, FTG and Matched Sets
Tooth geometry decides cut quality more than tooth count alone. Alternate Top Bevel (ATB) is the workhorse for clean crosscuts in solid wood and plywood; Triple Chip Grind (TCG) carries the load on metal, dense plastics and laminates where chip evacuation is hostile; Flat Top Grind (FTG) is the fast rip pattern with deep gullet volume. High-end wood blades pair ATB with a raker tooth (ATBR / 4+1 pattern) to break up tear-out on veneered panels. [S2]
Kerf width follows geometry and plate thickness: a full-kerf framing blade is 0.110 in (2.8 mm), a thin-kerf is 0.079 in (2.0 mm), and a ultra-thin-finish blade drops to 0.055 in (1.4 mm). Thin kerf reduces motor load and waste, but plate stiffness and runout tolerance drop with it — for saws under 15 A, thin-kerf is the practical ceiling before blade deflection starts lifting cut deviation above 0.005 in over 4 in of depth. For a broader selection framework across substrates, the spec levers for metal, wood and field work piece maps the same geometry logic to a wider tool list.
Body Materials and Tip Grades: HSS, TCT, Cermet, PCD
Body material is the fourth decision axis and it sets the upper temperature, RPM and abrasive-tolerance envelope. Cold-saw blades use solid high-speed steel (M2 or M35) bodies, often with cermet or carbide tips, running at 60–200 rpm with flood coolant to hold tooth temperature below the HSS tempering cliff around 540 °C (M2). Wood and aluminium blades use a thin-gauge steel plate (0.060–0.080 in) with brazed tungsten-carbide tips; the cermet variants cited by suppliers combine TiCN-coated carbide with a tougher substrate for longer life on aluminium and copper [S2].
Polycrystalline diamond (PCD) is the top of the wear-resistance stack and is specified for chipboard, MDF, fibreglass and carbon-fibre composites — the same tip lasts 30×–50× longer than TCT on abrasive particleboard, but PCD fails on iron-bearing materials because of a chemical reaction with cobalt binder around 700 °C. A 250–350 mm PCD panel-beam blade typically runs 48–72 teeth with a TCG or shear face geometry. For comparison, an HSS cold saw on the same 100 mm mild-steel solid bar will survive thousands of cuts where a TCT wood blade would fail in the first pass.
Speed, Feed and Chip Load: Operating Window
Cutting speed (sfm or m/min) is set by workpiece and tool material. HSS cold saws on mild steel run 250–400 sfm (75–120 m/min); cermet-tipped cold saws push to 500–700 sfm (150–210 m/min) at the same diameter. Carbide-tipped wood blades run much faster — 10,000–15,000 sfm surface speed on a 7-1/4 in framing blade means a no-load RPM near 5,800, dropping to 3,000–3,500 rpm in the cut to keep chip load in the 0.005–0.015 in/tooth range [S2].
Feed rate and chip load are coupled: doubling feed doubles chip load, which doubles heat input per tooth but also doubles material-removal rate. Practical ceilings sit around 0.020 in/tooth for HSS cold saws on mild steel, 0.015 in/tooth for cermet, and 0.005–0.010 in/tooth for PCD on composites. Push past those limits and tool life drops non-linearly — a 30% feed overspeed on a cermet blade can cut life by half.
Application Mapping: Wood, Metal, Composites, Field
Wood (rip): 10 in × 24T–30T FTG or 4+1 pattern, full-kerf, 3,000 rpm target, 0.015 in/tooth chip load on a 1.5 hp+ table saw. Wood (crosscut/finish): 10 in × 60T–80T ATB, thin-kerf 0.079 in, 3,500–4,500 rpm, finished edge ready for glue-up without sanding. Metal (ferrous): 250–350 mm HSS or cermet cold saw, 60–80T TCG, 60–200 rpm with flood coolant, bi-metal alternative for portable cut-off saws at 3,800 rpm dry with periodic rest. [S3]
Aluminium and non-ferrous: TCT or cermet, 60–80T TCG with deep gullet, 3,000–4,000 rpm dry or with mist coolant, 5–10° negative hook to keep blade from climbing. Composites (MDF, chipboard, fibreglass): PCD, 48–72T, 3,000–6,000 rpm, 0.005–0.010 in/tooth, dust extraction mandatory — fine PCD-grade dust is a respiratory hazard and abrasive on the machine ways. Field/general: cordless or corded 7-1/4 in framing saw with 24T or 40T combo blade covers framing, sheathing and trim cuts in one head, 5,800 rpm no-load, 0–57° bevel with depth detents at common lumber thicknesses.
Selection Criteria and Common Failure Modes
Match diameter to the deepest cut you make in 80% of work, then size motor and arbor to that head — over-spec on diameter and you under-feed the blade, polishing instead of cutting. Match tooth count to the finish requirement: a 24T blade on melamine will chip out the face veneer; an 80T blade on 2 in green lumber will stall a 15 A motor. Match body and tip to the workpiece temperature envelope, not just the material — HSS above 540 °C loses hardness, TCT above 900 °C oxidises, PCD reacts with iron above 700 °C. [S1]
Common failure modes trace back to three causes: (1) wrong tooth count for the material — tear-out on one side, burn marks on the other; (2) wrong chip load — blunt teeth from under-feed, missing teeth from over-feed; (3) wrong coolant regime — cold saws run dry fail at the HSS tempering cliff in seconds. Industrial saw-blade suppliers stock TCT, cermet, PCD and segmented product lines covering wood, aluminium and rip applications [S2], and Indian cutting-tool exporters ship HSS and TCT blades to similar tolerances for woodworking and shearing service [S1]. Specification discipline — diameter, kerf, tooth count, body, tip — is what separates a blade that lasts the shift from one that fails in the first cut. Related sourcing levers for tooling consumables run through the industrial lubricant price and cost guide, since flood and mist coolant choice swings blade life on metal by 3×–5×.
For component-level specifications, see circular saw, linear guide, and crossed roller guide.