Straight-blade, Spiral-blade, and Helical Planers and Jointers: What's the Difference?

If you're looking for a new planer or jointer, you've probably seen the wide variety of terms around a particular cutterhead - straight-blade, spiral-blade, helical, and more. Fret not, dear reader - your friends at WEN are here to offer some advice and clarity to make your purchasing decision easier. 

Straight blades

Perhaps the most common type of planer or jointer blade, these are exactly as the name suggests - straight and long. They're usually found on planers and jointers best suited to beginning or intermediate woodworkers. They're easy to replace and leave a good general-purpose finish on the wood, making any final sanding a breeze. 

Different grades of steel are often available for more choice within the range - some offer better durability or edge retention, others better finish, etc. WEN offers SK5 and M2 planer blades for all our straight-blade thickness planer models, and SK5 blades for our straight-blade jointer. As you gain experience, consider experimenting with different blade materials on different wood species to find the best balance for you.

Spiral blades

A step up from straight blades, these blades are found on higher-end machines, and are often preferred by experienced woodworkers for the excellent finish they leave on the wood - in some situations, sanding may not even be necessary. This is because instead of being one continuous piece of steel, they are segmented inserts spaced evenly across the tool's cutterhead. Think of them as the piranha counterpart to the straight blade's shark - they take many small bites out of the wood at a time, instead of one large chomp, producing the aforementioned finish. Additionally, many spiral blades are two- or four-sided, allowing you to rotate the cutting edges and get extended service life from your blades before replacing them. Spiral-blade machines tend to be more expensive than their straight-blade counterparts.

Helical blades

The most premium arrangement, these blades are mounted on specialized cutterheads, with many cutting inserts placed close together and arranged around the cutterhead in a helical pattern. This leaves a superior finish on the workpiece. However, helical cutterheads tend to be very expensive - sometimes more so than an entire thickness planer - and are best suited for professional woodworkers. They are often available as aftermarket accessories. 

Example of a helical cutterhead.

Summary

We hope this guide has been helpful! WEN offers a variety of straight-blade planers (models PL1252 and PL1303) and jointers (model JT3062) to suit your needs, as well as spiral-blade models (planer models PL1326 and PL1337, and jointer models JT630H, JT833H, JT1020H, and JT1224H). If you have any questions about the information in this article, or want help deciding which planer or jointer is right for you, please give us a call at 1-847-429-9263 (M - F, 8 - 5 CST) or drop us a message here to talk to our friendly and knowledgeable technical support team. Now go make some sawdust!