8 Or 12 Inch Jointer: Which Should You Buy?

When it comes to choosing a jointer for your woodworking shop, one of the biggest decisions is whether to get an 8 inch or 12 inch model. Both jointers have their pros and cons, so it really depends on your specific needs and budget. In this comprehensive guide, we’ll compare 8 vs 12 inch jointers to help you decide which is the right size for your projects.

8 Or 12 Inch Jointer

An 8 inch jointer is best suited for small shops working with narrower boards under 6 inches wide. It can handle smaller furniture components and projects efficiently while taking up minimal floorspace. However, a 12 inch jointer allows jointing stock up to 12 inches wide in a single pass. This added width capacity is extremely useful for wider surfaces like tabletops, large panels, and jointing warped plywood. The larger cutterhead and powerful 3-5 HP motors of a 12 inch jointer also provide superior stability and cutting action. While more expensive and requiring more space, upgrading to a heavy-duty 12 inch jointer is recommended for serious woodworkers who regularly surface wide boards. Just make sure to factor in the larger footprint into your shop layout.

Key Factors When Comparing 8 vs 12 Inch Jointers

When choosing between these two common jointer sizes, there are several key factors to consider:

  • Cutting width – The wider the cut, the larger boards you can joint in a single pass.
  • Cutterhead size – Larger cutterheads are more stable for smoothing warped boards.
  • Table length – Longer beds allow jointing longer boards in one go.
  • Power and precision – More horsepower means better cutting through hardwoods.
  • Cost – 12 inch jointers are a more significant investment than 8 inch models.

We’ll now look at each of these factors in detail when comparing 8 inch vs 12 inch jointers.

Cutting Width Capacity

The most obvious difference between these two sizes is the width of cut they can handle.

An 8 inch jointer can surface boards up to 8 inches wide in a single pass. This is adequate for smaller projects using narrower boards. But for wider surfaces like tabletops, you’ll be limited to edge gluing multiple narrow pieces.

A 12 inch jointer can joint boards up to 12 inches wide. This allows you to surface wider stock in a single pass without having to glue up narrower strips. The added capacity comes in handy when working with large slabs or flattening warped plywood and panelling.

So if you regularly work with wide boards, a 12 inch jointer will save you time and hassle. But an 8 inch is satisfactory for small to mid-size projects using 4-8 inch stock.

Cutterhead Size and Stability

Another key difference is the size of the cutterhead where the knives are mounted.

An 8 inch jointer usually has a cutterhead about 3 inches in diameter. This provides decent stability when surfacing wood.

A 12 inch jointer will have a larger 4 to 6 inch cutterhead. The bigger mass helps dampen vibration which improves cutting quality. The larger cutterhead also minimizes snipe (gouging at the end of a board).

So a 12 inch jointer’s cutterhead will generally provide a smoother cut and better handling of warped lumber. The smaller 8 inch cutterhead can still surface wood nicely but may struggle with severely twisted boards.

Table Length

The length of the jointer’s beds is also longer on a 12 inch model compared to an 8 inch.

An 8 inch jointer typically has beds around 4-6 feet long while a 12 inch model ranges from 6-8 feet.

The longer tables allow jointing boards in a single pass that might require multiple passes on a smaller jointer. Being able to flatten a long bowed board in one go reduces the risk of creating a twisted surface.

So if you regularly work with longer stock, the 12 inch jointer has the advantage. But an 8 inch bed length is usually sufficient for smaller projects.

Motor Power

Naturally, a larger 12 inch jointer requires more cutting power.

  • An 8 inch jointer may have a 1-2 HP motor which is adequate for the smaller cutterhead and depth of cut.
  • A 12 inch model bumps that up to 3-5+ HP in order to smoothly drive the bigger cutterhead through dense hardwoods. More horsepower also allows taking deeper cuts when surfacing twisted lumber.

If you mainly work with softer woods, the 8 inch jointer’s lower power may not be an issue. But for frequent use on hardwoods, the 12 inch motor power is beneficial. It provides the muscle to make clean, smooth cuts without slowing down in difficult material.

Precision and Adjustability

Higher-end 12 inch jointers often come with features that increase precision and ease of adjustment.

For example, parallelogram beds that reduce vibration and backlash. Precise adjustment mechanisms like rack and pinion tables. Larger handwheels that make it easier to fine tune the delicate cuts jointers require.

While some 8 inch jointers may include these upgrades, they are more commonly found on heavy-duty 12 inch models. If precision is a priority for your projects, upgrading to a larger jointer often improves the refinements.

Cost and Shop Space

Of course, there are practical considerations beyond just capability. An 8 inch jointer is smaller, lighter, and cheaper than a 12 inch model.

  • An 8 inch jointer may range from $300-$2000. Quality entry-level models can be under $1000 while still providing good performance.
  • A 12 inch jointer starts around $1000 and goes up to $5000+ for industrial shop machines. Expect to invest at least $1500-2000 to get a robust 12 inch model for an amateur workshop rather than a light-duty machine.

The larger jointers also require more workspace. A 12 inch jointer can take up twice the floor space of an 8 inch. Make sure you have adequate room available in your shop layout.

For hobbyists and weekend woodworkers on a budget, an 8 inch jointer is often the ideal size to get started. Then you can upgrade later if your projects demand it. But for a professional shop regularly surfacing wide stock, a heavy-duty 12 inch jointer is worth the premium.

Which Woods Are Better Suited to 8 vs 12 Inch?

The types of wood you’ll be joining also play a role. Here are some general guidelines:

An 8 inch jointer works well for:

  • Narrow hardwood boards under 6 inches wide
  • Softwoods like pine, cedar, spruce under 8 inches
  • Shorter boards around 2-4 feet long
  • Small to mid-size projects like furniture components, boxes, etc.

A 12 inch jointer handles these situations better:

  • Wide hardwood boards over 8 inches
  • Large slabs
  • Warped plywood over 8 inches
  • Long boards 6 feet or more
  • Large projects like tabletops, cabinets, doors

So consider which lumber you use most often. For example, if you mainly build with 4-5 inch hard maple boards, an 8 inch jointer has sufficient capacity. But if your passion is working with wide walnut slabs, invest in a 12 inch model.

8 vs 12 Inch Jointer: Pros and Cons compared

Here’s a quick recap of the key pros and cons of each jointer size:

8 Inch Jointer


  • Lower cost
  • Takes up less floorspace
  • Easier to transport and install
  • Adequate for small to mid-size projects
  • Can surface boards up to 8 inches wide


  • Limited to narrower stock
  • Not ideal for longer boards over 5 feet
  • May struggle with severely warped wood
  • Less powerful motors than 12 inch

12 Inch Jointer


  • Can surface stock up to 12 inches wide
  • Better with long boards up to 8 feet
  • Increased cutterhead stability and smoothness
  • More powerful 3-5HP motors
  • Longer tables for flattening bowed boards
  • Often better precision from upgrades like parallelogram beds


  • More expensive, $1500+ for quality models
  • Requires more shop space
  • Significant investment for hobbyists

Recommendations for Choosing 8 vs 12 inch Jointer

Based on all these considerations, here are some recommendations:

  • For a hobbyist woodworker on a budget, an 8 inch jointer is usually the best value choice. Models like the Cutech, Jet, Grizzly, or Porter Cable 8 inch jointers offer adequate performance for under $1000.
  • For small furniture shops working with mostly narrower hardwoods, an 8 inch jointer provides sufficient capacity while taking up minimal floorspace.
  • For professional shops surfacing wide boards daily, a heavy-duty 12 inch jointer is recommended, like the Powermatic or Jet 12 inch models.
  • If you can only afford one jointer, choose the 12 inch for the wider capacity. You can still surface narrower pieces on a 12 inch jointer.
  • For wide slabs or deeply warped lumber, a 12 inch 3-5HP model provides the best cutting power and stability.
  • If your shop only has room for a smaller machine, the 8 inch jointer makes the most sense space-wise.
  • For dedicated bowl and spindle turners using narrower stock, an 8 inch will handle most material.

So consider your budget, shop space, and types of wood projects. In many cases an 8 inch jointer is perfectly adequate. But for professionals surfacing large amounts of wide lumber, the 12 inch capacity becomes essential.

Features to Look for in 8 or 12 Inch Jointers

Whichever size you choose, here are some key features to look for:

  • Flat and parallel beds – Ensures workpiece stays true during surfacing
  • Precise fence adjustments – For accurate 90 and 45 degree angles
  • Rubber-coated infeed roller – Grabs the wood and prevents slippage
  • Cutterhead guard – Protects from flying chips during operation
  • Long beds – Allows jointing longer boards, key on a 12 inch jointer
  • Built-in mobile base – Makes it easy to move the heavy machine around the shop
  • Cutterhead lock – Locks the cutterhead for blade changes
  • Dust collection port – Captures dust and keeps the shop clean

These types of well-designed features maximize your jointer’s usability and safety. Investing in quality also ensures your machine will deliver years of reliable service.

In Summary

When trying to decide between an 8 vs 12 inch jointer, consider your budget, shop space, types of wood projects, and the width of your material. While an 8 inch jointer is often sufficient for smaller projects, a 12 inch model provides the capacity to surface wider and longer stock efficiently. Carefully evaluate your needs and choose the size that best fits your woodworking. With either machine, proper use, maintenance and safety practices will allow you to produce perfect joints and board faces.

Frequently Asked Questions about 8 vs 12 Inch Jointers

What size stock can an 8 inch jointer surface?

An 8 inch jointer can effectively surface boards up to 8 inches wide and around 6 feet long. The ideal material width for an 8 inch jointer is 4-6 inches.

What size stock can a 12 inch jointer handle?

A 12 inch jointer is capable of surfacing lumber up to 12 inches wide and 8 feet long. The added width capacity allows flattening large slabs in a single pass.

Can you still surface narrow boards on a 12 inch jointer?

Yes, a 12 inch jointer can safely joint boards well under its max capacity, even down to 2-3 inches wide if needed. The extra surface length also lets you flatten shorter boards efficiently.

What length boards can an 8 inch jointer flatten?

Most 8 inch jointers have 4-6 foot long beds. This lets you surface boards around 4 feet with support on both the infeed and outfeed tables. Longer boards up to 6 feet can work too but may need auxiliary support.

What size shops is an 8 inch jointer best suited for?

An 8 inch jointer is ideal for small to mid-sized hobbyist shops building furniture and smaller wood projects. It takes up minimal floor space while providing essential edge jointing functions.

When would a professional choose a 12 inch over 8 inch?

Pro woodworkers surfacing wide boards daily or flattening large slabs will benefit from upgrading to a 12 inch. The extra capacity and power boost productivity in a high-volume shop.

If I can only afford one jointer, should I get a 8 or 12 inch?

If budget only allows for one jointer, it’s generally better to get a 12 inch. While more expensive, you’ll gain the ability to surface wider boards in the future even if you currently only work with narrower stock.

What safety precautions should I take when using a jointer?

  • Use push blocks when edge jointing short or narrow boards
  • Don’t surface boards shorter than 10-12 inches long
  • Check for nails, knots or defects in wood before passing over cutterhead
  • Use jointer guards and keep hands away from the cutterhead
  • Make fence adjustments with machine off and unplugged
  • Wear eye and ear protection when running the jointer
  • Keep jointer blades sharp for cleanest cuts

What maintenance does a jointer require?

  • Regularly check belt tension and adjust as needed
  • Lubricate guide posts with oil or wax
  • Frequently clear dust buildup from under tables
  • Check cutterhead knives are secure and evenly set
  • Change dull/chipped knives to maintain sharpness
  • Clean pitch buildup from table to avoid rust

Can I convert an 8 inch jointer to a 12 inch?

Unfortunately no, the capacity difference requires completely distinct machine designs. The wider cutterhead, longer beds, and increased power of a 12 inch jointer cannot be achieved by modifying an 8 inch model. You’d have to purchase a whole new larger jointer.

I hope this comprehensive overview helps explain the key differences between 8 and 12 inch jointers! Let me know if you have any other questions.