Saw Blades Explained: Circular, Reciprocating & Diamond Blades for LA Job Sites

The blade decides the cut. A good saw with the wrong disc on it will burn, wander, chip the face of a panel or eat itself in half a wall, while a modest saw with the right blade does clean work all day. Three numbers do most of the deciding: tooth count on a circular blade, teeth per inch on a reciprocating blade, and rim type on a diamond blade. This guide covers what each one changes, which blade belongs on which material, and the LA-specific part almost nobody plans for, which is cutting masonry and fiber cement without breaking silica rules.

Tooth count sets the trade between speed and finish

On a circular blade, fewer teeth means bigger gullets, faster feed and a rougher edge; more teeth means a slower, cleaner cut. That is the whole rule. Everything else is a refinement of it.

Two things the table cannot carry. The first is that a framing blade is not a worse blade than a finish blade, it is a different tool. Ripping studs and cutting sheathing all day with a 24-tooth 7-1/4 in. framing disc is faster and puts less load on the saw than doing the same work with a 40-tooth blade, which would bog and heat up. Match the blade to the stage of the job, not to a general idea of quality.

The second is that tooth count interacts with what you are cutting through, not just what you are cutting. Blades described as "wood and nails" carry a tooth geometry and carbide grade meant to survive hitting a fastener, which is exactly what happens in demolition, in reused material and in any remodel where the old framing is full of surprises. The 40-tooth 7-1/4 in. wood-and-nails disc is the one to reach for when you want a reasonably clean cut but cannot promise the stock is clean.

Circular blades: framing, panels and finish

Framing is the easy case. A 24-tooth blade in 6-1/2 or 7-1/4 in. handles studs, joists, blocking and rough sheathing, and the smaller 6-1/2 in. framing disc is what most cordless saws take. If you are cutting shear panel or subfloor, the blade is barely the constraint; feed rate and a straight edge are.

Panel work is where tooth count starts to matter. Plywood veneer tears out on the exit side of the cut, so a 40-tooth blade, a shallow depth setting and cutting with the good face up on a circular saw all help. For sheet goods and trim in one saw, the 8-1/4 in. 40-tooth finishing disc covers both without a blade change. Our interior trim guide covers the miter and coping side of that work.

Fiber cement is its own category and this matters in Los Angeles, where siding is increasingly fiber cement for fire reasons. You do not cut it with a wood blade. The right tool is a very low tooth count polycrystalline diamond disc such as the 7-1/4 in. 4-tooth fiber cement disc or the 10 in. 6-tooth version for a table or miter saw, which produces less dust and does not destroy itself in a day. Our comparison of fiber cement, wood and engineered wood siding covers which material you will be cutting in the first place.

Reciprocating blades: TPI, length and demolition

A reciprocating saw is a demolition and access tool, and the blade number that matters is teeth per inch. Low TPI cuts fast and rough through wood; high TPI cuts slowly and cleanly through metal. The rule of thumb is that at least three teeth should be in contact with the material at all times, which is why thin metal needs a high TPI blade and a 2x needs a low one.

For wood with fasteners in it, which is most demolition, a bi-metal blade around 5 to 6 TPI is the workhorse. The 6 in. 5 TPI bi-metal five-pack and the 6 in. 6/12 TPI variable-pitch five-pack are both good general demo blades; the variable pitch handles mixed material better and runs a little smoother.

Length is the other half of the decision and it gets ignored. The blade has to clear the material on the push stroke or it will not cut, so a 12 in. blade such as the 12 in. 3 TPI is what you want for cutting through a stud wall or a 4x post, while a 6 in. blade gives you far more control in tight framing bays and is less likely to whip into a pipe you did not know was there. For mixed material where you cannot predict what is behind the wall, the 6 in. 8/14 TPI multipurpose or the multipurpose six-pack saves you swapping mid-cut.

Portable band saw blades follow the same logic with tighter tolerances, since band saws are mostly cutting conduit, strut and threaded rod. Higher TPI for thin wall, lower for solid stock. Our conduit guide covers what you are likely cutting on the electrical side.

Diamond blades: rim type is the whole decision

Diamond blades do not cut, they grind, and the rim geometry decides how aggressively and how cleanly. Segmented rims have gaps that clear spoil and cool the blade, so they cut fast and rough and are the standard for concrete and masonry. Continuous rims have no gaps, cut slower, and leave a chip-free edge, which is what tile needs. Turbo rims sit in between with a serrated profile that speeds up a continuous rim at some cost in edge quality.

What the table leaves out is wet versus dry. Continuous rim blades are generally designed to run wet, and running one dry for more than short cuts will overheat and glaze it. Segmented blades tolerate dry cutting far better, which is why they dominate on site. On a tile saw, you are cutting wet anyway.

For practical selection: a 4.5 in. masonry turbo three-pack lives in the grinder for cutting block, pavers and the occasional rebar tail. A 7 in. multipurpose turbo handles mixed material on a small saw. For cut-off saws and walk-behinds, the 12 in. masonry XTR segmented and the 14 in. thin-kerf segmented are the working sizes; thin kerf removes less material, which means less load and less dust. Tile work wants the 10 in. tile diamond, and our tile setting materials guide covers what goes under it.

Cutting masonry in Los Angeles without a silica problem

Every dry cut in concrete, block, stucco, mortar or fiber cement generates respirable crystalline silica, and Cal/OSHA treats that as a controlled exposure rather than a nuisance dust. In practice that means a blade choice is also a dust-control choice: wet cutting or an on-tool vacuum with a shroud, plus respiratory protection, is the expected setup rather than an optional upgrade.

Two blade-level things help. Thin-kerf segmented blades remove less material and therefore produce less dust for the same cut. And running the correct blade for the material keeps you from grinding away at something with a blade that is glazing, which is the situation that generates the most dust for the least progress. Our guide to respirators, dust masks and work gloves covers what the exposure rules actually ask for on an LA job site.

Getting more life out of a blade

Most blades die early for avoidable reasons. Heat is the main one: a blade that is forced, run at the wrong depth or pushed through material it was not made for will lose its carbide tips or glaze its diamond matrix long before its rated life. Let the blade feed at its own rate and back off when the pitch of the cut changes.

Depth of cut matters too. On a circular saw, setting the blade to project roughly a quarter inch past the material gives the cleanest cut and the safest kickback behavior; burying the blade to full depth on a thin panel just puts more teeth in contact and more heat in the blade. And a blade that has hit concrete or a nail once is not the blade to reach for when the cut has to look good.

The full range, from oscillating multi-tool blades through band saw stock to 14 in. diamond, sits in the power tool blades collection. Our earlier posts on oscillating blades and drill bit types cover the two cutting categories this guide does not. We deliver across Los Angeles County; tell us the saw and the material and we will match the blade.

Frequently asked questions

How many teeth should a circular saw blade have?

24 teeth for framing and rough sheathing, 40 for plywood and general trim, 60 or more for finish work and melamine, and 4 to 6 on a purpose-built fiber cement disc. Fewer teeth cut faster and rougher; more teeth cut slower and cleaner.

What TPI reciprocating blade do I need?

Low TPI around 3 to 6 for wood and demolition, 8 to 14 for mixed material, and 18 to 24 for metal. Keep at least three teeth in contact with the material at all times, which is what sets the minimum for thin stock.

Can I cut concrete with an abrasive wheel instead of a diamond blade?

You can, but abrasive wheels wear down as they cut, change diameter, cut slower and generate considerably more dust. A diamond blade holds its size and cuts faster, which matters more the longer the job runs.

What is the difference between segmented, turbo and continuous rim?

Segmented rims have gaps that clear debris and cool the blade, so they cut fast but leave a rough edge, which suits concrete and block. Continuous rims cut slowly and cleanly for tile and stone. Turbo rims are a serrated compromise between the two.

What blade should I use to cut fiber cement siding?

A dedicated fiber cement blade with 4 to 6 polycrystalline diamond teeth. Wood blades dull almost immediately on fiber cement and throw far more silica dust, so the specialist blade is both faster and safer.

Do I need a wet saw for diamond blades?

It depends on the blade. Continuous rim blades are usually designed to run wet and will glaze if run dry for long. Segmented blades tolerate dry cutting, but dust control is still required for silica-generating materials.