The Ridgid R4512 and Ridgid R4520 are closely related 10-inch cast-iron table saws, so the better buy is not simply “newer model wins.” Both sit in the same general class: a belt-driven, cast-iron-topped saw for garage shops, small furniture work, trim projects, and serious DIY woodworking.
The short answer: buy the R4520 if it is complete, well-aligned, and priced close to an R4512. Buy the R4512 if it is much cheaper, already tuned, and includes the guard, riving knife, throat plates, fence, miter gauge, and mobility base. On the used market, condition matters more than the model number.
This comparison also draws on the Ridgid R4512 operator’s manual, the Ridgid R4520 operator’s manual, archived product information, and practical owner-reported issues that rarely show up in basic product summaries.
Quick Verdict
The Ridgid R4520 is the better saw on paper. It keeps the same 13-amp, 3,450 RPM power class as the R4512 but adds a more modern safety and storage layout, a magnetic switch, and a 30-inch rip capacity listed on Home Depot’s R4520 product page.
The Ridgid R4512 can still be the smarter used buy. Its manual allows a larger dado stack than the R4520 manual specifies, and many used R4512s come from owners who have already upgraded the blade, added zero-clearance inserts, tuned the fence, or solved the alignment issues.
If you are choosing between the two locally, do not decide from the badge alone. Check alignment, fence behavior, missing safety parts, arbor condition, switch function, and included accessories before you pay.
Ridgid R4512 vs R4520 Specs at a Glance
| Feature | Ridgid R4512 | Ridgid R4520 | Why it matters |
|---|---|---|---|
| Blade size | 10 in. | 10 in. | No advantage either way. Both use standard 10-inch table saw blades. |
| Arbor | 5/8 in. | 5/8 in. | Standard arbor size for most 10-inch table saw blades. |
| No-load speed | 3,450 RPM | 3,450 RPM | Same listed blade speed. Real cutting quality depends more on blade sharpness, alignment, and feed rate. |
| Motor rating | 120V, 13 amps, 60 Hz | 120V, 13 amps, 60 Hz | Same headline motor rating. Neither should be treated like a 3 HP cabinet saw. |
| Blade tilt | 0° to 45° | 0° to 45° | Both handle common bevel cuts. |
| Cut depth at 90° | 3-1/4 in. | 3-1/8 in. | The R4512 has a slightly deeper listed 90° cut. |
| Cut depth at 45° | 2-1/4 in. | 2-1/4 in. | Same listed bevel cut depth. |
| Dado capacity | Up to 8 in. stacked dado, up to 13/16 in. wide, maximum depth 1-1/2 in. | Up to 6 in. stacked dado, up to 13/16 in. wide | This is one of the R4512’s real advantages if you cut dadoes often. |
| Rip capacity | Varies by rail setup; verify on the actual saw | 30 in. listed by Home Depot | The R4520 has the clearer published advantage for sheet goods. |
| Safety equipment | Blade guard, anti-kickback pawls, riving knife/spreader assembly | Blade guard, anti-kickback pawls, riving knife, magnetic switch | The R4520’s switch is the meaningful safety upgrade. |
| Best use case | Value used buy, dado work, tuned garage-shop saw | Better all-round used buy if complete and fairly priced | Choose based on condition, price, and completeness. |
What Changed from the R4512 to the R4520?
The R4520 did not reinvent the saw. It is better understood as a refinement of the same general idea: a full-size 10-inch table saw with a cast-iron table, belt-driven motor arrangement, mobile base, fence rails, miter gauge, blade guard system, and onboard storage.
The important changes are not raw power. Both saws list the same 13-amp motor rating and 3,450 RPM no-load speed. The difference is in the safety layout, capacity, switch system, accessory compatibility, and used-market risk.
Power: No Real Winner
The R4512 and R4520 are both rated at 13 amps and 3,450 RPM. That means the R4520 is not automatically stronger just because it is newer.
For practical woodworking, either saw can handle plywood, pine, poplar, oak, maple, and typical 4/4 hardwood when fitted with the right blade. The limit appears when you feed thick hardwood too aggressively, use a dull stock blade, rip wet lumber, or try to make cabinet-saw-level production cuts from a 120V saw.
A sharp 24T rip blade will usually outperform a dull general-purpose blade in thick hardwood. A 40T or 50T combination blade is better for mixed work. If a seller brags that the saw is “powerful,” ask what blade is installed and whether the saw bogs down while ripping 8/4 hardwood. The motor rating alone does not answer that.
Cutting Depth: Slight Edge to the R4512 at 90°
The R4512 manual lists a cutting depth of 3-1/4 in. at 0° and 2-1/4 in. at 45°. The R4520 manual lists 3-1/8 in. at 0° and 2-1/4 in. at 45°.
That 1/8 in. advantage for the R4512 at 90° will not matter for most plywood, trim, cabinet parts, or 4/4 stock. It can matter if you occasionally cut thicker material and want every bit of blade height available.
Dado Cuts: Clear Advantage to the R4512
This is the most overlooked difference between the two saws.
The R4512 manual says the saw is designed for an up to 8-inch stacked dado set, up to 13/16 in. wide, with a maximum depth of cut of 1-1/2 in. The R4520 manual’s FAQ/spec guidance points to an up to 6-inch stacked dado set, also up to 13/16 in. wide.
For most dado work, 6 inches is enough. A 6-inch stack has less rotating mass, which is easier on a 120V saw. But if you already own an 8-inch stacked dado set, or you want deeper dado capacity without buying another set, the R4512 has the better manual-supported specification.
Do not use a wobble dado on either saw. Use a stacked dado set, the correct dado throat plate, and follow the manual. Also check whether the used saw includes the dado insert. Missing inserts are common on second-hand table saws.
Safety Features
The R4520 has the better safety story, mainly because of the magnetic switch. A magnetic switch helps prevent the saw from restarting unexpectedly after a power interruption. That matters in a small shop where a breaker trip, unplugged extension cord, or power flicker can happen while the saw is set up for a cut.
Both saws use a blade guard, anti-kickback pawls, and a riving knife or spreader-style assembly depending on the setup. On the used market, the bigger question is whether those parts are still with the saw. Many used saws are sold with the guard, pawls, or riving knife missing because the previous owner removed them and never reinstalled them.
Do not treat a missing riving knife as a minor inconvenience. A riving knife helps keep the kerf from closing behind the blade and reduces kickback risk. If the seller cannot provide the guard and riving knife assembly, factor replacement cost and availability into your offer.
Fence and Alignment: The Real Used-Buy Test
The fence matters more than most spec tables admit. A table saw with a strong motor but a drifting fence is frustrating and dangerous.
On older Ridgid contractor-style saws, owners often discuss fence alignment, rail cleanliness, and blade-to-miter-slot alignment. Woodworker Keaton Beyer, writing about a Ridgid R4512 fence, noted that his fence began migrating toward the blade at the back, creating a kickback risk until he cleaned and adjusted the system. That is exactly the kind of practical issue a used buyer should check before handing over money.
Before buying either saw, bring a combination square or dial indicator if the seller allows it. At minimum, do these checks:
- Lock the fence at the front and try to wiggle the rear. It should not drift toward the blade.
- Measure from the fence to the same blade tooth at the front and back of the blade.
- Slide the fence along the rails and check whether it locks consistently at different widths.
- Check the rail faces for dents, pitch, sawdust buildup, and missing fasteners.
- Raise and lower the blade fully. The mechanism should move smoothly without grinding or binding.
If the fence points slightly away from the blade at the rear, that can be acceptable depending on the manual and adjustment method. If it points into the back of the blade, walk away or budget time for adjustment before using the saw.
Trunnions and Blade Parallelism
The trunnion system controls the blade carriage. On a table saw, blade-to-miter-slot alignment affects burn marks, cut accuracy, noise, and kickback risk. This is one reason used R4512 and R4520 buyers should care less about cosmetic scratches and more about mechanical adjustment.
The R4512 manual includes a “heeling” adjustment for paralleling the blade to the miter gauge groove. In owner discussions, the R4512 is often mentioned as a saw that can be made accurate, but the adjustment can be fiddly because shifting the trunnion while tightening bolts may move the setting again.
A practical approach is to mark one blade tooth, measure it at the front of the blade, rotate that same tooth to the back, and measure again from the same miter slot. You are trying to compare the same tooth, not two different teeth, because blade runout can otherwise fool you.
If the seller says “it cuts straight,” still check it. Many hobbyists do not notice a small alignment issue until they start ripping hardwood, building cabinets, or using a sled.
Dust Collection
Both saws benefit from dust collection, but neither should be expected to perform like a sealed cabinet saw. The R4512 manual refers to a dust chute for use with a 4-inch dust collection system. The R4520 manual also describes dust discharge and shop-vac connection.
If you are using a shop vacuum, expect decent pickup around the lower cabinet but not perfect collection above the blade. For better results, use a proper dust collector, keep the chute clear, and use the blade guard when possible because above-table dust is a major part of the mess.
When inspecting a used saw, open the cabinet or look underneath. Packed sawdust around the elevation screw, belt, motor area, and trunnion can make the controls feel worse than they are. It can also hide rust, missing bolts, or previous repairs.
Mobility and Shop Footprint
The R4512 and R4520 are both meant for shops where the saw may need to move. That is a major advantage over a heavier cabinet saw and a major reason these models remain attractive second-hand.
Check the mobile base before buying. The saw should lift and roll without twisting the stand. Test the caster pedal, wheel condition, and frame fasteners. A saw that has been dragged across a garage floor for years may have rail or base alignment problems even if the cast-iron top looks fine.
Build Quality and Durability
The cast-iron top is the main reason these saws appeal to woodworkers who want something better than a lightweight jobsite saw. Cast iron adds mass, helps damp vibration, and gives you a flatter, more stable surface for furniture parts, cabinet panels, and repeatable ripping.
Still, “cast iron” does not automatically mean “accurate.” Check the table for rust pitting, raised dents near the miter slots, cracked wings, missing extension bolts, and uneven side tables. Surface rust can often be cleaned. Deep pitting near the blade opening or miter slots is more concerning.
Known Used-Buy Issues to Check
These are the checks that matter more than a polished sales photo:
- Missing safety parts: Confirm the blade guard, anti-kickback pawls, riving knife or spreader assembly, push stick, throat plate, and blade wrenches are included.
- Fence drift: Make sure the rear of the fence does not pull toward the blade when locked.
- Blade alignment: Check whether the blade is parallel to the miter slot.
- Elevation and bevel controls: Raise, lower, tilt, and return the blade to 90°. Stiff controls may only need cleaning, but they may also indicate neglect.
- Arbor condition: Listen for vibration and watch for blade wobble. Do not assume wobble is “just the blade.”
- Switch function: Test on/off operation. On the R4520, confirm the magnetic switch behaves correctly.
- Dado insert: If dado work matters, confirm the correct dado throat plate is included or available.
- Rust: Light surface rust is normal on used cast iron. Severe pitting, especially near the blade opening or miter slots, is a bargaining point.
- Rails and fasteners: Missing rail bolts or misaligned rails can make the fence unreliable.
Ridgid R4512 Overview
The Ridgid R4512 is a 10-inch cast-iron table saw with a 13-amp motor, 3,450 RPM no-load speed, 5/8-inch arbor, and 0° to 45° blade tilt. It is a good choice for a hobbyist or small-shop woodworker who wants more mass and table stability than a portable jobsite saw.
What the R4512 Does Well
- Good used value: Because it is older, the R4512 can be cheaper than the R4520.
- 8-inch dado support: The manual-supported dado capacity is a real advantage over the R4520 if dado work matters.
- Cast-iron table: Better work support and vibration control than most compact jobsite saws.
- Repairable layout: The belt-driven design and manual adjustment procedures make it more serviceable than many sealed portable saws.
Where the R4512 Falls Short
- Older used-market risk: Many examples have missing guards, worn fences, rusty tops, or alignment issues.
- No clear safety upgrade like the R4520 magnetic switch: The R4520 has the better modern switch arrangement.
- Setup can be fussy: Blade-to-slot alignment and fence adjustment need patience.
Ridgid R4520 Overview
The Ridgid R4520 is the newer 10-inch cast-iron model. The manual lists the same 13-amp, 120V, 3,450 RPM power class as the R4512, with a 5/8-inch arbor, 0° to 45° blade tilt, 3-1/8-inch cut depth at 90°, and 2-1/4-inch cut depth at 45°.
Home Depot’s R4520 product page listed a 30-inch rip capacity, 13-amp motor, 10-inch carbide-tipped blade, push stick, accessories, and eligibility for free parts and service for life with registration.
What the R4520 Does Well
- Better safety layout: The magnetic switch is the main improvement.
- Good rip capacity: The listed 30-inch rip capacity is useful for plywood and larger panels.
- Modernized storage and guard system: The R4520 manual shows dedicated storage areas for the rip fence, push stick, blade guard assembly, anti-kickback pawls, riving knife, blade, and wrenches.
- Better default recommendation: If condition and price are similar, the R4520 is usually the better buy.
Where the R4520 Falls Short
- Smaller listed dado diameter: The R4520 manual guidance points to a 6-inch stacked dado set rather than the R4512’s 8-inch stacked dado allowance.
- Not more powerful: It shares the same listed motor rating and no-load speed as the R4512.
- Used examples still need inspection: A newer model with a bad fence setup or missing riving knife is not safer than a complete, tuned R4512.
Which One Is Better for Different Users?
Best for Most Buyers: Ridgid R4520
The R4520 is the better all-round choice if the used price is reasonable and the saw is complete. The magnetic switch, 30-inch rip capacity, and updated layout make it easier to recommend to most home-shop users.
Best for Dado Work: Ridgid R4512
If you regularly cut dados, rabbets, grooves, and cabinet joinery, the R4512 deserves a serious look because the manual allows an 8-inch stacked dado set up to 13/16 in. wide. That does not mean it is always better, but it is a real technical advantage.
Best Budget Buy: Depends on Condition
A clean R4512 with the safety gear, dado insert, upgraded blade, smooth controls, and a tuned fence can be a better buy than a neglected R4520. A complete, lightly used R4520 is better than a rusty R4512 missing half its parts.
Best for Sheet Goods: Ridgid R4520
The R4520’s listed 30-inch rip capacity gives it the clearer advantage for plywood, MDF, melamine, and cabinet panels. You will still want outfeed support for full sheets.
Used Price Guidance
Used prices vary by region, accessories, condition, and how quickly the seller wants the saw gone. Instead of relying on one fixed number, compare local listings and ask these questions:
- Does it include the blade guard, riving knife, pawls, miter gauge, rip fence, throat plate, dado insert, push stick, and wrenches?
- Is there an upgraded blade included?
- Has the seller tuned the fence and blade alignment?
- Is the cast-iron top lightly rusty or deeply pitted?
- Can the seller demonstrate the saw running?
- Does the mobile base work properly?
Pay more for a complete, tuned saw. Pay less for missing safety parts, missing inserts, rust, switch problems, fence drift, or uncertain alignment.
R4512 vs R4520 Buying Checklist
Use this checklist when inspecting either saw:
- Confirm the model number. Check the badge, not just the seller’s title.
- Inspect the cast-iron top. Look for rust, pitting, cracks, dents, and uneven wings.
- Check the fence. Lock it at several positions and make sure it stays parallel.
- Check blade-to-miter-slot alignment. Use the same marked tooth at the front and back of the blade.
- Test the height and bevel mechanisms. They should move smoothly and lock securely.
- Verify safety parts. Do not ignore missing riving knives, guards, or pawls.
- Listen to the motor and belt. Watch for vibration, squealing, wobble, or slow startup.
- Check dado compatibility. Ask whether the dado throat plate is included.
- Check parts availability before buying a damaged saw. Do not assume every discontinued part is easy to find.
Common Mistakes When Comparing These Two Saws
Mistake 1: Assuming the R4520 Is More Powerful
It is newer, but the manuals list the same 13-amp motor rating and 3,450 RPM no-load speed. If you want better cutting performance, start with alignment and blade choice.
Mistake 2: Ignoring Dado Capacity
The R4512’s 8-inch stacked dado allowance is easy to miss. If you build cabinets, bookcases, drawers, or shelving, this may matter more than the R4520’s newer switch.
Mistake 3: Buying a Saw Without the Safety Gear
Many used table saws are sold incomplete. A missing guard or riving knife is not just a missing accessory. It changes the risk profile of the tool.
Mistake 4: Not Testing the Fence
A fence that locks crooked can cause burning, wandering cuts, and kickback risk. It is one of the first things to inspect.
Mistake 5: Overpaying for a Rusty Saw Because It Has a Cast-Iron Top
Cast iron is good, but neglected cast iron is work. Light surface rust is manageable. Deep pitting and damaged miter slots are harder to justify.
Alternatives to Consider
If neither saw is available in good condition, compare them with similar used or current saws in the same general category. Common alternatives include the Delta 36-725 and 36-725T2, used Craftsman contractor saws, older Ridgid R4511 units, and newer portable Ridgid jobsite saws.
A jobsite saw may be better if you need portability more than cast iron. A cabinet saw may be better if you rip thick hardwood every week, need more power, or want a heavier fence system. The R4512 and R4520 sit between those worlds.
Final Recommendation
Choose the Ridgid R4520 if you want the better default used buy, value the magnetic switch, need a 30-inch rip capacity, and find one that is complete and properly aligned.
Choose the Ridgid R4512 if it is significantly cheaper, in better condition, already tuned, or you specifically want the manual-supported 8-inch stacked dado capacity.
Avoid either saw if the fence will not lock square, the arbor or blade visibly wobbles, the safety equipment is missing and hard to replace, the switch behaves unpredictably, or the seller will not let you see it run.
The R4520 is newer and generally the better pick, but the best table saw is the one that is complete, safe, aligned, and priced honestly. A clean R4512 can beat a neglected R4520 every time.