Thickness Planer Guide

Complete reference for thickness planers including setup, depth settings, grain direction, snipe prevention, and milling rough lumber to precise dimensions.

Planer Types

Benchtop Thickness Planer

  • 12" to 13" cutting width
  • Portable, typically 50-80 lbs
  • 6" maximum thickness capacity
  • Two-knife or three-knife cutterhead
  • Best for: DIY, hobbyist, small shop

Stationary Thickness Planer

  • 15" to 20"+ cutting width
  • Heavy duty, 300-800+ lbs
  • 8"+ thickness capacity
  • Helical or spiral cutterheads available
  • Best for: professional shops, production work

Electric Hand Planer

  • 3-1/4" to 6-1/8" cutting width
  • Handheld, portable
  • For edge work, trimming, fitting doors
  • Not for dimensioning lumber
  • Best for: on-site work, carpentry, edge planing

Jointer vs. Planer

  • Jointer: Flattens one face and edges
  • Planer: Makes opposite face parallel
  • Planer alone can't flatten warped boards
  • Use jointer first, then planer for flat stock
Depth of Cut Settings
DepthUse CaseNotes
1/32" (0.8mm)Final smoothing, hardwoodsBest finish quality
1/16" (1.5mm)General dimensioningGood balance of speed/finish
3/32" (2.4mm)Removing mill marksSoftwoods, light passes
1/8" (3.2mm)Rough stock removalMaximum for most benchtops

Rule of Thumb

Take lighter passes for better finish quality. Heavy cuts stress the motor, dull blades faster, and increase tearout risk. Multiple light passes beat one heavy cut.

Grain Direction & Feed

Reading the Grain

  • Look at the board edge to see grain direction
  • Grain should slope DOWN toward feed direction
  • Think: "downhill" direction reduces tearout
  • Mark arrows on boards before planing

Dealing with Reversing Grain

  • Some boards have grain going both directions
  • Take very light passes (1/64" if possible)
  • Wet the surface slightly to reduce tearout
  • Consider a hand plane for final cleanup

Feed Rate

  • Let the planer pull the board - don't push
  • Slower feed = better finish
  • Fast feed can cause ripples/chatter
  • Variable speed planers: slow for hardwood, fast for softwood
Snipe Prevention

What is Snipe?

  • Deeper cut at the beginning or end of board
  • Caused when only one roller is engaging
  • Most common issue with benchtop planers
  • Usually 1-3" at each end

Prevention Techniques

  • Support the work: Use infeed/outfeed tables at exact bed height
  • Lift slightly: Support board ends as they enter/exit
  • Use sacrificial boards: Feed scrap before and after
  • Gang plane: Feed boards end-to-end continuously
  • Lock head: Some planers have head lock mechanism

Dealing with Snipe

  • Cut boards 2-4" longer than needed
  • Trim sniped ends after planing
  • Hand plane or sand to remove minor snipe
Milling Rough Lumber

The Four-Square Process

  1. Face joint: Flatten one face on jointer
  2. Edge joint: Square one edge to face on jointer
  3. Plane: Opposite face parallel on planer
  4. Rip: Opposite edge parallel on table saw

Without a Jointer

  • Build a planer sled/jig to hold warped boards
  • Use wedges to stabilize rocking boards
  • Shim gaps with cardboard or hot glue
  • First passes create one flat face
  • Remove from sled, flip, plane normally

Rough Lumber Tips

  • Let lumber acclimate before milling
  • Mill in stages if removing lots of material
  • Check for embedded metal/debris first
  • Plane both faces equally to balance stresses
Minimum & Maximum Dimensions
DimensionBenchtop (12-13")Stationary (15"+)
Min thickness1/4" - 3/8"1/8" - 1/4"
Max thickness6"8" - 12"
Min length8" - 12"12" - 18"
Max width12" - 13"15" - 20"+

Warning

Never plane boards shorter than the minimum length - they can kick back or get caught. Use a carrier board/sled for thin stock to prevent breaking.

Blade/Knife Maintenance

Blade Types

  • HSS (High Speed Steel): Can be resharpened, common
  • Carbide: Longer life, more expensive
  • Disposable/Indexable: Double-sided, replace don't sharpen
  • Helical head: Many small carbide inserts, quieter, rotate when dull

Signs of Dull Blades

  • Fuzzy or rough surface finish
  • Increased tearout, even with good grain
  • Burnished/glazed spots on wood
  • Motor straining on normal cuts
  • More dust, less chips

Setting Blades

  • All blades must be at exactly the same height
  • Use manufacturer's jig or magnetic setting gauge
  • Uneven blades cause steps/ridges in surface
  • Replace/rotate all blades at once
Safety & Best Practices

Required PPE

  • Hearing protection: Planers are very loud (90+ dB)
  • Safety glasses: Chips can fly out
  • Dust collection: Essential - huge dust output

Safe Operation

  • Never reach under or into the planer while running
  • Keep hands clear of infeed and outfeed
  • Don't plane boards with loose knots or defects
  • Check for metal (nails, staples) before planing
  • Stand to the side, not directly behind outfeed

Dust Collection

  • 4" dust port is standard - use proper hose
  • Planers produce more chips than any other tool
  • Shop vac usually insufficient - use dust collector
  • Clear chips regularly to prevent clogging

Additional Information

About This Thickness Planer Guide

A thickness planer is essential for any woodworker who wants to mill their own lumber or needs precise thickness control. While buying surfaced lumber (S4S) is convenient, planing your own rough lumber opens up access to specialty species, saves money, and gives you exact control over final dimensions.

Understanding the difference between a jointer and planer is fundamental. A planer cannot flatten a warped board - it only makes the top surface parallel to the bottom. If you run a cupped board through a planer, you'll get a thinner cupped board. The jointer creates the reference flat face; the planer creates the parallel face.

Snipe is the most common frustration with benchtop planers, but it's manageable with proper technique. Using infeed and outfeed support at the exact bed height, lifting board ends slightly as they enter and exit, or simply cutting boards longer and trimming the ends are all effective solutions.

Why Use This Reference Guide?

Quick reference for planer setup and technique helps achieve flat, smooth lumber with consistent dimensions.

  • Understand depth of cut settings for different woods
  • Read grain direction to minimize tearout
  • Prevent and deal with snipe issues
  • Mill rough lumber using proper sequencing
  • Maintain blades for best surface quality
  • Know minimum/maximum dimensions for safe operation
Frequently Asked Questions

Free Thickness Planer Guide - Milling Lumber, Depth Settings & Snipe Prevention | DIYProject.ai