The Stanley Numbering System Explained
Last reviewed on 2026-04-24
The Stanley numbering system has been the de facto standard for classifying bench plane sizes since the 1870s. Even planes not made by Stanley — Record, Sargent, Millers Falls, Lie-Nielsen, Veritas — are typically described in Stanley-equivalent numbers because those numbers are what every hand-tool woodworker recognizes. Understanding the system is essential for buying planes, reading old catalogs, and communicating with other woodworkers.
How the Numbers Are Organized
Stanley's numbering is not a perfect arithmetic sequence. It grew organically as the product line expanded. The general rule: within a given family (bench planes, block planes, specialty), lower numbers are shorter or smaller and higher numbers are longer or larger. The bench plane series from No. 1 through No. 8 is the most consistent — each number is progressively longer and wider.
The "½" suffix indicates a wider version of the same length. A No. 4½ is the same 9 inches long as a No. 4 but carries a 2⅜-inch iron instead of a 2-inch iron, and its casting is heavier to match. Woodworkers who favor a 4½ over a 4 usually cite the extra mass for quieting chatter on figured wood.
The Basic Numbers
No. 1 - Thumb Plane (5½" long)
The smallest bench plane, rarely seen. Collectible but not practical for most work.
No. 2 - Smoothing Plane (7" long)
Small smoother, 1⅝" iron. Good for musical instruments and small work.
No. 3 - Smoothing Plane (8" long)
Compact smoother with 1¾" iron. Popular for small projects and finishing work.
No. 4 - Smoothing Plane (9" long)
The standard smoothing plane. 2" iron. This is the most common and versatile size. Perfect first plane.
No. 4½ - Smoothing Plane (10" long)
Wider than No. 4 with 2⅜" iron. More mass helps reduce chatter in figured wood.
No. 5 - Jack Plane (14" long)
The "jack of all trades." 2" iron. Can smooth, joint edges, and dimension stock. Extremely versatile.
No. 5½ - Jack Plane (15" long)
Longer and wider than No. 5 with 2⅜" iron. More stable for edge jointing.
No. 6 - Fore Plane (18" long)
Uncommon size between jack and jointer. 2⅜" iron. Less popular than No. 5 or No. 7.
No. 7 - Jointer Plane (22" long)
Long jointer for flattening boards and jointing long edges. 2⅜" iron. Essential for serious hand tool work.
No. 8 - Jointer Plane (24" long)
The longest standard bench plane. 2⅝" iron. Maximum flatness for large work.
Specialty Designations
Block Planes
- No. 9½: Standard angle block plane
- No. 60½: Low angle block plane (most popular)
- No. 65: Low angle block plane with adjustable mouth
Other Planes
- No. 71: Router plane
- No. 78: Rabbet plane
- No. 90: Bullnose rabbet plane
- No. 92: Shoulder plane
The "½" Designation
Planes with ½ added (4½, 5½) are wider versions with heavier castings. They cost more but offer better stability and reduced chatter.