Before You Start
A type study classifies Stanley Bailey bench planes by the manufacturing changes Stanley made over their 100-year production run. By examining specific physical features (the adjuster nut, the lateral lever, the frog and frog receiver, patent dates cast into the bed, and markings on the body) you can determine approximately when your plane was made.
No single feature is definitive on its own. Stanley routinely assembled planes from inventory, so a plane might carry parts from adjacent types. Always verify at least three features before assigning a type. This guide is based on the #4 size; other sizes share most features but may vary in bed-marking locations and some casting details.
Five Features to Examine
Work through these in order. The adjuster nut and lateral lever are the fastest first steps.
Depth Adjuster Nut
Is it solid brass or recessed (hollow)? What text is stamped on it: "BAILEY, WOODS & CO.", "BAILEY'S PATENT", or plain? Is the thread right-handed or left-handed? This alone narrows you to a range of types.
Lateral Lever
Is there one at all? (Types 1–4 have none.) If present: is it an "L" shape (Type 5 only) or two-piece with a rotating disc? Count the patent dates stamped on it. Does it read "STANLEY" vertically?
Patent Dates Behind Frog
Look at the bed casting behind the frog. Zero dates (Types 1 to 8), two dates: MAR-25-02 and AUG-19-02 (Types 9 to 12), or three dates with APR-19-10 added (Types 11 to 12). Combined with the frog screw, this pins the type exactly.
Frog Adjustment Screw
Present or absent? This small screw below the frog first appears at Type 10 and is present on all subsequent types, except some Type 17s made during wartime.
Knob Height & Bed Markings
Is the front knob low or dramatically tall (Type 12+)? Is there a raised ring at the knob base (Types 14+)? What text is cast into the bed: "BAILEY", "MADE IN USA", and where does it appear (at the toe or behind the frog)?
Iron Stamp Quick Reference
A-1 (1866?–1874): Earliest Stanley mark. Most common on Type 1 Boston planes.
J (1874–1884): Standard mark for pre-lateral Bailey planes.
P (1886–1890): Single-letter mark.
Q (1891–1904): Single-letter mark. General Stanley tools.
S (1907–1909): Corresponds to Types 10–11. Note: distinct from the "S" foundry casting mark found on Type 7 beds, which is a different usage.
T (1909–1912): Corresponds to Types 10–11.
V (1912–1918): Corresponds to Type 11, WWI era.
X (1919–1920): First Sweetheart trademark. Earliest Type 12.
Y (1921–1922): Second Sweetheart era stamp. Type 12.
AA (1923–1926): Third Sweetheart era stamp. Type 13.
BB (1936+): Late Type 16.
Type-by-Type Identification Guide
Colour Key
- No lateral adjustment lever
- Low front knob with bead at base
- Plane size not cast in bed; size incised under frog and lever cap
- Solid brass adjuster nut stamped "BAILEY, WOODS & CO." / "BOSTON" / "PATENTED" with patent dates Aug. 31, 1858 and Aug. 6, 1867 · right-hand thread
- Banjo-shaped spring under lever cap
- Keyhole-shaped hole in lever cap · no logo on lever cap
- Circular hole in cutter at the top of the slot
- No lateral adjustment lever · low front knob with bead at base
- Solid brass adjuster nut · right-hand thread
- Adjuster nut stamped "BAILEY'S PATENT" with patent dates (vs. "BAILEY, WOODS & CO." on Type 1)
- Rectangular spring under lever cap (replaces the banjo style of Type 1)
- Keyhole-shaped hole in lever cap · no logo on lever cap
- No lateral adjustment lever · low front knob with bead at base
- Completely different two-piece frog design: smaller frog held by a vertical rib between the casting sides; the same frog fits all sizes #3 to #8 (an attempted interchangeable-parts economy, quickly abandoned)
- Small depth adjuster nut (1"), now recessed (was solid on Types 1–2)
- Adjuster nut stamped "BAILEY'S PATENT" · right-hand thread
- Keyhole-shaped hole in lever cap · no logo on lever cap
- No lateral adjustment lever · low front knob with bead at base
- Plane size not cast in bed
- Back to a one-piece frog (Type 3's two-piece design abandoned)
- Small recessed depth adjuster nut (1") stamped "BAILEY'S PATENT" with two patents: Aug 31, 1858; Aug 6, 1867 · right-hand thread
- Flat-headed frog screws (vs. round-headed on earlier types)
- Some examples: foundry numbers "73" or "71" cast in bed
- Keyhole-shaped hole in lever cap · no logo on lever cap
- Lateral adjustment lever, first time ever. One-piece "L"-shaped design; this shape appears on Type 5 only. Stamped with two patent dates: 2-8-76 and 10-21-84 (some examples only)
- Plane size now cast into the toe in front of the knob (first time in casting rather than incised)
- Low front knob with bead at base · "Bailey" not cast in bed
- Small recessed depth adjuster nut (1") stamped "BAILEY'S PATENT" · right-hand thread
- Keyhole-shaped hole in lever cap · no logo on lever cap
- Circular hole in cutter at the top of the slot
- Lateral lever now two-piece with a rotating circular disc (replaces the one-piece "L" shape of Type 5). Three patent dates: 2-8-76, 10-21-84, 7-24-88 + STANLEY
- Low front knob, bead removed
- Depth adjuster nut thread switches to left-hand
- Circular hole in cutter moves to the bottom of the slot
- Frog receiver now has two shallow parallel grooves with screw holes in the grooves
- Small recessed nut (1") stamped "BAILEY'S PATENT" · plane size at toe · "Bailey" not in bed
- Keyhole-shaped hole in lever cap · no logo on lever cap
- "S" (Sessions Foundry mark) cast into frog, lever cap, and/or bed
- Plane size numbers spaced further apart at toe
- Three patent dates on lateral lever + STANLEY · low front knob (no bead)
- Most examples: right-hand thread on adjuster nut (note: reverted from left-hand of Type 6)
- Small recessed nut (1") · "Bailey" not cast in bed
- Keyhole-shaped hole in lever cap · no logo on lever cap
- "B" cast into frog, lever cap, and/or bed (new foundry, replacing "S")
- Left-hand thread on adjuster nut (reverted back from Type 7's right-hand)
- Only one patent date on lateral lever (reduced from three)
- Low front knob (no bead) · small recessed nut (1") · "Bailey" not cast in bed
- Keyhole-shaped hole in lever cap · no logo on lever cap
- Plane size now cast behind the knob (was in front of knob on Types 5–8)
- "BAILEY" cast into toe in front of the knob (as tribute to the inventor; not a Boston-era feature)
- Two patent dates cast behind frog: MAR-25-02 and AUG-19-02
- Center rib added to frog receiver, enabling precise lateral frog registration
- No frog adjustment screw · lateral lever has no patent dates, just "STANLEY"
- Low front knob (no bead) · small recessed nut (1") · left-hand thread
- Keyhole-shaped hole in lever cap · no logo on lever cap
- Frog adjustment screw added
- Center rib in frog receiver enlarged and arched
- Two patent dates behind frog (MAR-25-02, AUG-19-02) · "BAILEY" at toe · "STANLEY" on lateral lever
- Low front knob · small recessed nut (1") · left-hand thread
- Keyhole-shaped hole in lever cap · no logo on lever cap
- Third patent date added behind frog: APR-19-10 (now three: MAR-25-02, AUG-19-02, APR-19-10)
- Frog adjustment screw · "BAILEY" at toe · "STANLEY" on lateral lever
- Low front knob · small recessed nut (1") · left-hand thread
- Keyhole-shaped hole in lever cap · no logo on lever cap
- High front knob, dramatically taller than all previous types
- Large depth adjuster nut (1¼"), first appearance of the larger nut
- Slightly longer rib on back of frog, first appearance
- Three patent dates behind frog · frog adjustment screw · "BAILEY" at toe
- Keyhole-shaped hole in lever cap · no logo on lever cap · "STANLEY" on lateral lever
- Only one patent date behind frog: US PAT APR-19-10 (the Mar-25-02 and Aug-19-02 dates removed)
- Stanley logo now appears on lever cap, first appearance
- Wide variety of lever cap finishes: machined with japanned background, fully nickel-plated, nickel with orange/red/yellow painted background
- Note: some Type 13 frogs were painted orange
- High front knob · large nut (1¼") · "BAILEY" at toe · frog adjustment screw
- Keyhole-shaped hole in lever cap · "STANLEY" on lateral lever
- Raised ring cast into bed at toe for the knob, first appearance; prevents stress fractures caused by the tall high knob
- "MADE IN U.S.A." cast at toe in front of knob: first and only type with this marking at this position. "BAILEY" moves to behind the knob
- Note: some Type 14 frogs were painted orange
- One patent date behind frog · high front knob · large nut (1¼") · frog adjustment screw
- Keyhole-shaped hole in lever cap · Stanley logo on lever cap · "STANLEY" on lateral lever
- "MADE IN U.S.A." moves to behind the frog, no longer at the toe
- Plane size cast in toe in front of knob (first appearance at this position)
- "BAILEY" cast behind the knob (moved from toe; first appearance at this position)
- Note: some Type 15 frogs were painted orange. On larger sizes, "MADE IN U.S.A." may be further back (behind tote)
- High front knob with raised ring · large nut (1¼") · frog adjustment screw
- Keyhole-shaped hole in lever cap · Stanley logo on lever cap · "STANLEY" on lateral lever
- Kidney-shaped hole in lever cap (replaces keyhole), designed to prevent the iron from loosening during depth adjustment
- New ogee (S-curve) profile on frog
- Raised, broad, flat rib cast at heel (smaller sizes); at both toe and heel (#5 and larger)
- "MADE IN U.S.A." behind frog · "BAILEY" behind knob · raised knob ring · frog adjustment screw
- Stanley logo on lever cap · "STANLEY" on lateral lever · high front knob · large nut (1¼")
- Depth adjuster nut of steel or hard rubber (brass rationed)
- Hardwood knob and tote instead of rosewood, stained red or painted black
- Heavier, thicker castings, with coarser machining on many examples
- Frog adjustment screw may be absent on some examples (stock inconsistency)
- Kidney-shaped hole in lever cap · ogee frog · raised rib at toe/heel · "MADE IN U.S.A." behind frog
- Brass adjuster nut reintroduced with diagonal knurling (also present on early Type 19)
- Hardwood knob and tote usually painted black, slightly different design from Type 17
- Kidney-shaped hole in lever cap · ogee frog · frog adjustment screw
- Raised rib at toe/heel · "MADE IN U.S.A." behind frog · Stanley logo on lever cap
- "STANLEY" incised vertically on the lateral adjustment lever
- Y-shaped frog base in bottom casting
- May be rosewood or hardwood painted black; early examples have diagonal knurling on adjuster nut
- Frog adjustment screw · ogee frog · kidney-shaped hole in lever cap
- Stanley logo on lever cap · raised rib at toe/heel · "MADE IN U.S.A." behind frog
- All castings painted blue; black japanning discontinued
- One-piece folded lateral adjuster (new design; "STANLEY" no longer stamped on it)
- Hardwood knob and tote stained in a new lighter style
- Y-shaped frog base · frog adjustment screw · ogee frog · kidney-shaped hole in lever cap
- Stanley logo on lever cap · raised rib at toe/heel · "MADE IN U.S.A." behind frog
Not sure yet? Try the interactive wizard
Answer a series of questions about what you see on your plane; the wizard narrows it down to a type automatically.
Open the Identification Wizard →Frequently Asked Questions
What is the easiest way to identify a Stanley bench plane? +
Start with the depth adjuster nut and the lateral lever. Is the nut solid or recessed, and what does it say? Does a lateral lever exist at all? If so, how many patent dates are on it? These two features together narrow you to 3–4 types in under a minute.
Then check how many patent dates are cast into the bed behind the frog and whether a frog adjustment screw is present. This combination pins Types 9–12 exactly. For later types, check whether the casting is black or blue, and whether "STANLEY" is incised vertically on the lateral lever.
Each type entry in this guide has a Quick ID callout with the shortest reliable combination for that type.
My plane has features from two different types. Which type is it? +
Very common. Stanley assembled planes from inventory parts, so a plane might have a newer body casting with an older lever cap or tote. This is called "the spare parts problem."
Assign the type based on the body casting features: frog receiver shape, patent dates behind frog, and bed markings (MADE IN U.S.A., BAILEY, foundry letters). These are structural and harder to swap accidentally. Note the mixed features in your records; they can actually bracket the manufacturing date more precisely than a "pure" example.
Does this type study apply to all Stanley Bailey sizes? +
Mostly yes, with some exceptions documented by Roger Smith:
The #1 never had a lateral lever or number marking. The #2's number marking was intermittent 1885–1915. The #1, #2, #10, #10¼, and #10½ never received the raised frog receiver introduced by the 1902 patents. The #4½ wasn't offered until 1884; the #5½ until 1898; the #5¼ until 1922. The #8 was eliminated in 1958.
For all other sizes, the type features apply uniformly. Bed-marking locations (toe vs. heel) may vary by size, but the presence or absence of markings follows the type study.
Can I use this guide for Canadian or English Stanley planes? +
With caution. This type study is based on American production. Canadian planes (often marked MADE IN CANADA) broadly parallel US types but frequently diverge in casting marks and timing. English planes (Stanley's Sheffield factory) follow a separate manufacturing evolution. Use this guide as a rough starting point but expect differences.