Best Router Sled in 2023: Excellent Slab Flattening Mill

best slab flattening mill

You’ve got a new router for shaping that fine-looking slab of hardwood. But, if this is your first time woodworking, know that you can’t achieve the perfect shape by relying on the router only.

Why is that so?

Because the router needs some guidance! To be able to slide your router to and fro on different types of wood smoothly, you’ll need to attach the device to a router sled. The sled secures the router into place while allowing you to rout with accuracy.

Now if you’re planning on purchasing a router sled, you shouldn’t just choose any but the best router sled for woodworking. We know that it can be hard to find one, which is why we’ve done the research and listed our top choices below.

Good luck with your search!

Comparison Table of Slab Flattening Router Jig



Maximum Capacity (inches)

Weight (lbs)


Stone Coat Countertops Slab Jig



Woodhaven 3000 27" Planing Sled



Woodpeckers Extended Slab Flattening Mill

62 x 105 or 38 x 129


How To Choose The Right Router Sled: Buyer’s Guide

Best Slab Flattening Mill

Quality Of The Material

The first thing you’ll need to consider when choosing the best router sled is the quality of the material. Typically, router jigs are made of extruded aluminum, which is far stronger and smoother than cast aluminum. This material choice makes it easy to slide a router along the sled’s width.

Still, you will have to pay attention to the material’s quality because sleds can be made either with high-grade or low-grade aluminum. We recommend you look for a sled made of high-grade aluminum as it is sturdy and offers outstanding corrosion resistance.


Not all router sleds have the same slab accommodating capacity. Some can hold a width of about 27 inches while others can hold slabs as large as 60 inches. There are also sleds that come with an extender that you can use to increase the width of the cross rails or the length of the base rails.

So, before you purchase a slab flattening jig, make sure it is capable of accommodating the size of the slab you’ll be working on.


For precise routing, the slab jig must be secured tightly to the work table. Clamps would do the job perfectly.

A clamp holds the sled tightly to prevent it from moving as you slide the router. The stronger the hold, the better precision you will achieve from flattening the wood slabs.

Whichever router flattening jig you choose for your projects, make sure to check the quality of the clamps it comes with.

Router Plate

Most router sleds come with a router plate that you can install to your router for flattening slabs and start working on your projects. It makes routing a breeze. But, the main concern to take note of is whether your router’s base fits the hole in the plate.

As long as the router plate is universal, there’s no need to worry. You’ll want to own a universal router plate because it will come in handy even if you plan on replacing your current router with the one from a different manufacturer. That way, you can save costs on purchasing a router plate separately. 

Best Slab Flattening Mill Reviews

1. Stone Coat Countertops Slab flattening Jig – Router Sled for Woodworking

Stone Coat Countertops Slab flattening Jig – Router Sled for Woodworking
Manufacturer‎Stone Coat Countertops
Part Number‎696292850227
Item Weight‎22 pounds
Package Dimensions‎73 x 8.8 x 8.5 inches
Batteries Included?‎No
Batteries Required?‎No

Stone Coat Countertops aims in saving your money by delivering quality home improvement products, including a slab flattening router jig.

The Slab Jig by this manufacturer is designed to flatten wood slabs despite their condition. It can straighten warped, skewed, or bowed wood slabs without a hitch. You can also use it to level an epoxy-filled wooden piece. Since it is made of extruded aluminum, it will keep its shape no matter how frequently you use it for your projects.

What makes this the best router sled is its versatility. You have the option of adjusting the rails according to the size of your table and flattening slabs of a maximum width of 64 inches. Even if you need to work with thicker wood slabs, you can slide wood blocks under the rails to elevate the height.

If you’re wondering whether your router will fit into the router plate, you don’t have to worry because the plate’s opening is large enough to hold a fixed-base router by most manufacturers. Also, the plate locks itself firmly on the router sled to add security as you focus on your project.

Assembling this jig requires no professional skills, which is a bonus point. It comes with all the hardware you need to set it up. Moreover, you’ll find a clear instruction video for the setup process online.

Highlighted Features:

  • Smoothly levels warped, skewed, or bowed slabs
  • Holds slabs up to 64 inches wide
  • Does not bend during routing
  • The base plate accommodates routers by most manufacturers
  • Comes with hardware for assembly

2. Woodhaven 3000 27″ Planing Sled

Woodhaven 3000 27
Part Number‎3000
Item Weight‎20 pounds
Package Dimensions‎48 x 6 x 6 inches
Is Discontinued By Manufacturer‎No
Size‎3000: 27″
Batteries Included?‎No
Batteries Required?‎No

Woodhaven is also another top-class manufacturer that offers a range of woodworking tools for the convenience of woodworkers and homeowners alike.

The Woodhaven 3000 planing sled does an excellent job in straightening different types of slabs, such as a live edge and butcher block. What can’t be easily achieved with a planer is possible with this amazing tool.

This particular router planing sled is capable of accommodating slabs up to 27 inches wide. But, you’ll also find models that accommodate slabs of a maximum width of 39 inches, 51 inches, 63 inches, and 86 inches. Depending on the size of the slab you need to work on, you can decide on a jig having the appropriate maximum capacity.

The 36-inch Ultra Track rails ensure the router stays supported in between them while you move the device forwards and backwards. There are also Double Track rails that allow you to smoothly move your router sideways. The rails are made of extruded aluminum, so there’s no chance of any mishap. 

If you need to increase the height of the sled when working with thicker slabs, you’ll need to add a couple of wood rails.

What you’ll like about the base plate, you don’t have to use a drilling machine to attach your router to it. It allows easy attachment, so whenever you need to change the bit, you can do so within minutes.

Speaking of the bit, this slab planing jig supports a minimum length and a maximum diameter of 2.5 inches.

Highlighted Features:

  • Can accommodate slabs up to 27 inches wide
  • Extruded aluminum rails ensure the router remains in place
  • The base plate allows easy attachment for router
  • Requires wood rails for increasing the height of the sled
  • Supports bits having a minimum length and a maximum diameter of 2.5 inches

3. Woodpeckers Extended Slab Flattening Mill

Woodpeckers Extended Slab Flattening Mill
Manufacturer‎Woodpeckers LLC
Part Number‎SLBFLTXL
Item Weight‎79 pounds
Product Dimensions‎80 x 11 x 5 inches
Country of Origin‎USA

As its name suggests, Woodpeckers is dedicated to providing you with everything you need for woodworking.

One of its notable woodworking tools is the extended slab flattening mill. It allows you to turn those live edge slabs into a flawless masterpiece. Whether you’re doing home improvement or woodworking on a professional level, you will greatly benefit from this sled.

Starting with the rails, they are made of extruded aluminum. The ribbed design minimizes deflection while the inverted V-shaped top prevents dust from settling on it. To enhance smoother routing, there are strips of UHMW plastic located in the areas where the metal components come into contact.

If you plan on investing in a sled that you can also use for large slabs, you can rely on this best slab flattening mill. It features rail extensions that you can use to expand not only the width but also the length of the slab. All you need to do is attach the rails using connectors and secure them with a hex key.

What’s interesting, the router plate that comes with this wood slab mill can accommodate 14 different router bases. If you have a large-sized router, you can also mount it to the plate. Additionally, the ergonomic handles ensure a comfortable grip as you work for long hours.

You’ll have no trouble in setting up this sled because it comes with clamps as well as all the assembly hardware needed.

Highlighted Features:

  • UHMW plastic strips minimize friction during routing
  • The router plate accommodates 14 different router bases
  • Includes rail extensions for accommodating larger slabs
  • Ergonomic handles ensure a comfortable grip
  • Includes assembly hardware

Frequently Asked Questions

1. Do I Need To Be Trained To Use A Sled?

Using a sled doesn’t require any training. As long as you know how to use a router and follow the instructions that come with your sled, you’ll be good to go!

2. How To Keep A Sled Safe?

If your router sled is made of metal, it can rust when it comes into contact with water. And if it’s made of wood and water gets inside, microorganisms can grow and damage the sled’s structure. Therefore, it is recommended you store your router sled in a cool, dry place.

Also Related: How to flatten edge slab – Explaining difference method.

3. How To Maintain Safety While Using A Router Sled?

Routing involves flying dust particles, loud noises, and the risk of injuries. So, every time you start a woodworking project, it is essential you take adequate safety measurements. Make sure to wear gloves, goggles, ear protection, and a face mask.

Apart from safety equipment, make sure that the router and the sled are assembled properly.

4. Is A Router Sled Necessary?

Yes, it is essential that you use a router sled for woodworking. When you’re flattening a large slab of wood with a router, it’s the router sled that supports the machine and lets you make multiple passes with ease. You can either purchase a router sled or build one on your own.

Final Word

When you have the router integrated with a sled, you’ll notice how convenient it becomes. Regardless of the size of the slab your project calls for, you’ll have no trouble leveling it neatly.

That being said, you’ll achieve the optimal output only with the best router sled. Such sleds top in both quality and performance that other sleds fall short of. After researching plenty of router sleds in the market, luckily, we have come across the above ones possessing those qualities. 

Before adding a slab planer to your shopping cart, we recommend you to go through the buying guide to know whether you’re getting what you really need.

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