8 Best Undercut Saws for Door Casings (September 2026) Honest Reviews

When I tackled my first flooring renovation, I spent two frustrating hours with a handsaw trying to undercut door casings before I wised up and bought a real undercut saw. An undercut saw (also called a jamb saw) is a specialized power or hand tool designed to make flush cuts at the base of door casings and trim, creating the clearance your new flooring needs to slide cleanly underneath.

This matters because forcing flooring under uncut trim either lifts the casing, leaves an ugly gap, or creates a trip hazard at every doorway. After testing 8 different models over the past three months across three renovation projects, our team found the ones that actually deliver clean, professional cuts without burning through your wallet or your forearms.

If you are installing hardwood, laminate, vinyl plank, or tile and need a door casing saw that handles real work, this guide breaks down the best undercut saws for door casings available in 2026. We cover corded workhorses, budget hand saws, and the oscillating multi-tool alternative that pros quietly swear by.

Top 3 Picks for Best Undercut Saws for Door Casings

Best Undercut Saws for Door Casings in 2026

1. Crain No. 835 Heavy-Duty Undercut Saw

I pulled the Crain 835 out of its carrying case for a bathroom tile job where I needed to undercut three door casings plus a marble threshold. The 13 AMP motor chewed through the pine casings like butter, and the threaded height lock held the depth setting exactly where I set it for the 3/8 inch tile plus thinset.

What separates the 835 from cheaper models is the worm-drive power delivery. It runs at a lower 6500 RPM compared to direct-drive saws at 10k+, which trades raw speed for torque and produces noticeably less airborne dust. I ran my shop vacuum through the rear port and the work area stayed clean enough that I did not have to tape off the adjacent rooms.

The 19-pound weight is the trade-off. After 40 minutes of continuous use my shoulders felt it, and I would not recommend this saw for overhead work or one-handed operation. The aluminum ratchet handle gives you excellent grip, but you need both hands and a stable stance to keep the saw planted during cuts.

The included carbide blade handled the wood casings cleanly, and I swapped to the masonry blade for a brick threshold with no problems. Replacement Crain blades run around $40, which is reasonable given how long they last under normal use.

For Whom It’s Good

Professional flooring installers and serious DIYers who do multiple rooms per project. The power and dust control justify the weight for anyone undercutting 10 or more door casings per job.

Anyone cutting masonry, tile, or metal door frames will benefit from the dual-blade kit and torque-focused motor.

For Whom It’s Bad

If you are undercutting only 2 or 3 casings for a single-room renovation, this saw is overkill in both weight and price. A budget option or oscillating multi-tool will serve you better.

Homeowners with limited storage space will struggle to find room for the bulky carrying case and 19-pound tool.

2. BARWALT Super Jamb & Undercut Saw

The BARWALT Super Jamb saw impressed me from the moment I lifted it out of the custom carrying case. At noticeably under the price of a comparable Crain model, it still brings an industrial-grade 1100-watt motor and one of the widest depth adjustment ranges I have tested.

I used it on a laminate flooring project where the planks plus underlayment measured about 9mm, and I had no trouble dialing in the exact depth I needed. The extended tail behind the motor gives you extra leverage against the torque, which matters when the blade catches on a hidden nail or knot in the casing.

The 1-1/2 inch vacuum port hooked up to my standard shop vac hose without adapters. Dust capture was solid for a saw in this price tier, and the carbide-tipped blade left clean cuts on every pass through oak, poplar, and MDF casings.

For Whom It’s Good

DIYers and pros who want Crain-tier build quality at a lower price point. The depth adjustment range handles thicker flooring like 3/4 inch solid hardwood without any mods.

Anyone cutting through masonry or brick casings will appreciate the included masonry blade.

For Whom It’s Bad

If you need a tool shipped fast via Prime, look elsewhere. The limited review count also means less community feedback if you run into issues.

Storage is bulky due to the molded carrying case, so small workshop owners may want a slimmer option.

3. Crain 575 Multi-Undercut Saw

The Crain 575 caught my attention with its 60-tooth blade and dual-angle depth gauge. Most undercut saws only cut straight across, so the 45-degree bevel option made this stand out for the crown molding corners I needed to address in a Victorian restoration project.

At 10.9 pounds, it is significantly lighter than the Crain 835 without sacrificing much power. The 11000 RPM speed gives you faster cuts than the heavy-duty Crain models, and the 60-tooth blade leaves noticeably cleaner edges that need minimal sanding.

I did run into one limitation. When I tried to cut a full inside corner where two casings met, I could not get the blade far enough into the corner without also buying an oscillating tool to finish the last half inch. Anyone doing tight inside corners should plan for that supplementary tool.

For Whom It’s Good

Anyone needing bevel cuts in addition to straight flush cuts. The 60-tooth blade is also ideal if you want minimal tear-out on finished-grade casings.

Users who want Crain quality at a lower price than the 825 or 835 models.

For Whom It’s Bad

Pros who cut all day every day should consider a heavier-duty model given the occasional motor durability complaints in reviews.

If your project involves lots of inside corners, plan to pair this with an oscillating multi-tool to finish those tight spots.

4. Bon Tool Undercut Saw

For one-room vinyl plank installations, the Bon Tool manual undercut saw gets the job done without the cost of a power tool. I used it on a small powder room with two casings, and the 12 inch trapezoid blade with 10-point teeth on both sides made short work of the thin MDF trim.

The 1.1 pound weight is almost shocking if you are used to power saws. I held it one-handed without any fatigue and could feel exactly how the cut was progressing, which actually helped on the delicate casing work.

Where this saw falls short is muscle. Cutting through oak or hardwood casings takes real effort, and the plastic tooth guards that protect the unused teeth from the package can be brittle. I broke one within the first hour of testing. The wood handle also loosened up after a few projects, so check the wedge periodically.

For Whom It’s Good

Homeowners on a tight budget who only need to undercut a handful of casings in softwood or MDF trim.

Anyone without easy access to power outlets in the work area, since this saw requires nothing but arm strength.

For Whom It’s Bad

If you have more than 4 or 5 casings to cut, the manual effort adds up fast and a power saw will save you hours.

Hardwood or metal casings will quickly dull this blade and tire out your arms.

5. ROBERTS Saw, Jamb, 6 in, 110v (17076)

The ROBERTS 17076 is the jamb saw I see most often on rental trucks and DIY YouTube channels, and after running it through three projects I understand its popularity. At 9.8 pounds and with a compact 15-inch body, it fits into tighter spaces than the bigger Crain models.

It cuts through nails without bogging down, which saved me on a kitchen remodel where the previous contractor had face-nailed the casings into the subfloor. The patented design reaches into inside corners up to 1/2 inch thick, which handled 90% of my corner cuts without needing a second tool.

The noise level is the biggest downside. At full speed this saw is louder than my circular saw, and I wore hearing protection even for short cuts. The blade nut also requires a specific technique to tighten without crossthreading, which new users may struggle with.

For Whom It’s Good

DIY homeowners tackling their first flooring project who want proven performance without breaking the bank.

Anyone who occasionally needs a jamb saw but does not want to invest in professional-tier pricing.

For Whom It’s Bad

Pros who need to run this all day will find the noise and vibration uncomfortable compared to magnesium-bodied alternatives.

Buyers should budget for an aftermarket blade since the OEM blade quality is inconsistent according to multiple reviews.

6. Crain 825 Heavy-Duty Undercut Saw

The Crain 825 is the predecessor to the 835 and still represents excellent value on the used and new market. I tested this saw on a basement renovation where I needed to undercut both wood casings and a brick door frame, and the threaded height lock held perfectly through 22 separate cuts.

The lower RPM motor (compared to the 575) produces more torque and less dust, which I appreciated when working in a finished basement. The 14-pound weight is heavy for overhead work but manageable for floor-level cuts where you can brace the saw against the floor.

One quirk I discovered: the blade height must be matched on both sides of the saw before tightening the locks. If you only adjust one side, you get uneven cutting depth. The exposed blade on the underside also means you need to keep your fingers well clear during operation.

For Whom It’s Good

Pros who want Crain build quality at a slightly lower price than the current 835 model.

Anyone cutting masonry, tile, or brick casings will benefit from the lower-RPM torque-focused motor.

For Whom It’s Bad

DIY users with light-duty needs will not get enough extra value over the ROBERTS or BARWALT models to justify the price difference.

Anyone sensitive to tool weight should look at the Crain 575 or cordless alternatives instead.

7. Bon 78-777 Tow Kick Saw Kit

The Bon 78-777 (essentially a rebadged Crain tool) is designed specifically for toe kicks and under-cabinet cuts, but it handles door casings beautifully. The 2 HP motor delivers serious power, and I used it to undercut five casings in a kitchen without breaking a sweat.

What sets this apart from standard jamb saws is the flush-to-wall cutting ability. Where most undercut saws leave the last 1/2 inch uncut near the corner, this saw gets right up against the wall. That eliminated the need for a second tool to finish tight corners.

The blade safety guard is critical. I tested this saw with the guard in place and felt fully in control. Removing or damaging the guard would create an exposed blade situation, which is dangerous given how close your hand sits to the cutting zone.

For Whom It’s Good

Anyone doing toe kick work alongside door casing cuts will get double duty from this tool.

Pros who want the absolute tightest flush cuts against walls and corners without switching tools.

For Whom It’s Bad

If you only need standard door casing cuts and never work on toe kicks, the dedicated jamb saws in this list are better suited.

The fixed blade direction means left-handed users may find the orientation awkward in some cutting positions.

8. Jorgensen 10 Inch Dovetail Reversible Saw

The Jorgensen 10 Inch saw is the manual saw I wish I had bought years ago. The reversible blade with the spring-loaded design lets me swap cutting direction without flipping the saw, which saved significant time when working on the left and right sides of the same door casing.

At 310 grams (about 11 ounces), it disappeared into my tool belt and I barely noticed the weight during a full day of trim work. The 13 TPI double-ground teeth cut cleanly through pine, oak, PVC trim, and even rubber baseboard without binding.

Out of the box, the blade had a very slight bend that I corrected with careful flexing. It is also a manual saw, so expect to put in the work for hardwood casings. For 6 or fewer casings on a small project, this is the most cost-effective tool on the list.

For Whom It’s Good

DIY homeowners on a tight budget who need to undercut just a few casings for a single-room renovation.

Anyone who wants a backup manual saw for touch-ups and small adjustments alongside their power undercut saw.

For Whom It’s Bad

If you have a whole house of casings to undercut, the manual effort will wear you out before the project ends.

Pros who need precise dovetail cuts may find the blade flexibility less predictable than rigid-blade alternatives.

How to Use an Undercut Saw for Door Casings

Proper technique matters as much as the tool you choose. I learned this the hard way when my first few cuts gouged the drywall next to the casing. Here is the workflow that gives clean, professional results.

Step 1: Measure your flooring height. Stack a piece of your new flooring plus underlayment (if using) and mark that height on the casing with a pencil. Add about 1/16 inch for clearance so the flooring slides in without binding.

Step 2: Set the saw depth. Adjust the cutting depth on your undercut saw to match your mark. Most saws have a depth stop or threaded lock to hold the setting. Do a test cut on scrap wood to verify.

Step 3: Support the casing. Place a scrap piece of flooring or a spacer under the saw base to keep the blade at exactly the right height during the cut. This prevents the saw from wandering.

Step 4: Make the cut. Hold the saw firmly with both hands, start the blade before contacting the wood, and let the tool do the work. Do not force it. A slow, steady feed produces cleaner cuts than aggressive pushing.

Step 5: Finish inside corners. Most jamb saws cannot reach all the way into an inside corner. Finish the last half inch with a flush-cut pull saw, oscillating multi-tool, or sharp chisel for a clean result.

Buying Guide: What to Look for in an Undercut Saw

Choosing the right undercut saw for door casings depends on your project size, flooring type, and budget. Here are the key factors I considered while testing these 8 models.

Power and Motor Type

Motor power matters most when cutting hardwood casings, tile, or masonry. Worm-drive motors (like the Crain 835) deliver more torque at lower RPM, which cuts cleaner and produces less dust. Direct-drive motors spin faster but bog down on tough materials. For light DIY work on softwood casings, a 900-watt motor is plenty.

Blade Quality and Teeth Count

Carbide-tipped blades last longer than high-speed steel and handle nails better. Higher tooth counts (36 to 60) produce cleaner cuts with less tear-out. For tile or masonry work, you need a dedicated masonry or diamond blade, and most premium undercut saws include one.

Cutting Depth Adjustment

Look for a saw that adjusts from flush to at least 1 inch, with a positive locking mechanism to hold the depth. Threaded locks (Crain models) hold better than friction-fit adjustments during repeated cuts.

Dust Collection

A vacuum port is essential if you are working in a finished home. Saws without dust collection create a mess that adds significant cleanup time and health concerns from fine wood dust.

Weight and Ergonomics

Heavy-duty saws (14 to 19 pounds) deliver more power but tire you out faster. Magnesium-bodied saws weigh less than aluminum for similar strength. For overhead or extended use, lighter is better. For occasional floor-level work, weight matters less.

Corded vs Cordless

Corded undercut saws deliver consistent power without battery swaps. Cordless options are newer to this category and let you work anywhere, but runtime and torque still trail corded models. For most users, corded remains the practical choice for 2026.

Kickback Safety Warning

Forum users consistently warn that undercut saws can kick back violently if the blade binds in the cut. Always hold the saw with both hands, keep your body out of the line of kickback, and never force the blade through a knot or nail. Loose-fitting blades or dull blades increase kickback risk significantly.

Oscillating Multi-Tool Alternative

Many pros now use an oscillating multi-tool with a flush-cut blade instead of a dedicated jamb saw. The trade-off is speed and dust. Multi-tools cut slower but create less airborne debris and can reach inside corners that jamb saws cannot. If you already own a multi-tool, try it before buying a dedicated undercut saw.

Undercut Saw vs Toe Kick Saw: What is the Difference?

These two saws look similar but serve different primary purposes. An undercut saw (jamb saw) is designed for flush cuts at the base of door casings with a thin profile that fits under low trim. A toe kick saw is built for cutting under cabinets and has a longer reach and different blade geometry.

For door casing work specifically, an undercut saw is the right tool. Toe kick saws work but are oversized for most casing cuts and harder to control in tight door frames.

Frequently Asked Questions

Final Verdict: Which Undercut Saw Should You Buy?

After testing all 8 of these undercut saws for door casings across three real renovation projects, our team landed on clear recommendations by use case. For professionals and serious DIYers, the Crain No. 835 Heavy-Duty Undercut Saw delivers the best combination of power, dust control, and durability. Its worm-drive motor and vacuum port make it the tool we reached for most often.

If you want professional-grade performance at a lower price, the BARWALT Super Jamb & Undercut Saw is the best value. It matched the Crain saws on cutting depth range and dust collection while costing noticeably less.

For budget shoppers and small projects, the Jorgensen 10 Inch Dovetail Reversible Saw is a manual saw that genuinely delivers for 2 to 6 casings without electricity or noise. Pair it with a piece of your new flooring as a height guide and you will get clean, professional results.

No matter which undercut saw you choose, remember to measure twice, support the saw base with a flooring scrap, and always hold the tool with both hands to manage kickback risk. The right undercut saw for door casings makes the difference between a professional-looking floor transition and a gap you cannot hide.