The Decade LEGO Began Building a Future in Plastic

LEGO history in the 1940s is often reduced to a clean transformation: a wooden-toy company discovered plastic and created the LEGO brick. The transition was slower and more complicated.

Wooden toys remained part of LEGO’s business during the decade and were still represented in its product history in 1949. A workshop fire disrupted the company in 1942, but did not end its wooden-toy era. LEGO added its first injection-molding machine in late 1947, spent 1948 gaining experience with the process, and introduced several plastic products in 1949. Among them were Automatic Binding Bricks, the company’s first plastic building blocks.

Those blocks were historically important, but they were not yet the mature modern LEGO brick. They were made from cellulose acetate, had hollow undersides, and drew on the earlier Kiddicraft Self-Locking Building Bricks associated with British inventor Hilary Fisher Page. Nor did plastic immediately displace wood: LEGO’s own historical index identifies a wooden single bus from 1949, the same year the first plastic building set appeared.

The pivotal development of the decade was therefore coexistence rather than replacement. LEGO entered the plastic age while it was still a wooden-toy manufacturer.

LEGO in the 1940s at a Glance: A Documented Timeline

The principal dates come from three different kinds of account: LEGO’s corporate history, a collector publication covering wooden toys, and an unsigned archived enthusiast page about early plastic bricks. They do not carry equal evidentiary weight, so LEGO events must be distinguished from developments involving Page and Kiddicraft.

Year	Reported development	Historical significance
1940	Hilary Fisher Page’s Kiddicraft Self-Locking Building Brick was patented in the United Kingdom.	This was an earlier British plastic block, not a LEGO product or patent.
1942	A collector history reports that fire damaged LEGO’s workshop.	The event interrupted LEGO’s wooden-toy period, but wooden products remained part of the business afterward.
Late 1947	LEGO says its first plastic injection-molding machine arrived and was installed beside the woodworking operation after initial testing.	The company gained a new manufacturing capability without immediately abandoning wood.
1948	According to LEGO, employees experimented with plastic molding and became more familiar with the process.	This was a learning period between acquiring the machinery and releasing commercial plastic products.
1949	LEGO manufactured several kinds of plastic toys, including Automatic Binding Bricks, its first plastic building blocks.	The year began LEGO’s plastic-building-block business, but not the later worldwide LEGO System.

The 1940 Kiddicraft patent date and the reported physical form of Page’s early block appear in an unsigned archived Technica page about the 1949 brick. Because that page is an enthusiast account rather than the patent record itself, its description is best treated as a secondary historical source.

LEGO’s corporate account places the arrival of the molding machine in late 1947, the learning period in 1948, and the first commercial plastic products in 1949. It also says the company’s toys were then sold exclusively in Denmark and describes Automatic Binding Bricks as “relatively successful,” without providing sales totals in its history of Automatic Binding Bricks.

The timeline establishes the decade’s central theme. LEGO did not pass through a single doorway from wood to plastic. It maintained an established wooden-toy operation while acquiring machinery, developing experience with a new process, and introducing a different material category.

The sequence does not establish why LEGO invested in injection molding. It also does not show that the 1942 fire caused the later purchase or that any particular wartime condition dictated the decision. Chronology alone cannot supply those missing explanations.

Before Plastic Bricks: LEGO’s Wooden-Toy Business

LEGO entered the 1940s as an experienced wooden-toy maker. That activity had begun before the decade and continued well after the first plastic blocks appeared. The late-1940s experiments with molding therefore took place inside a company that still produced familiar wooden playthings, not one already devoted exclusively to construction toys.

Its documented wooden range included vehicles, animal pull toys, and other playthings. These categories are important because LEGO’s early identity cannot be reduced either to the brick or to one famous wooden object. It operated a varied toy business.

The wooden duck nevertheless provides a tangible illustration. When pulled, the toy opened and closed its mouth. Later versions reportedly included a mechanism that produced a quacking sound. The cord supplied the motion, and the toy responded through its moving mouth and, in some versions, sound. The duck appears alongside wooden vehicles and other pull toys in a collector guide to LEGO’s wooden products.

For understanding the transition to plastic, the more revealing object may be LEGO’s wooden single bus dated 1949. Its date places a wooden vehicle in the same year as Automatic Binding Bricks. Without proving how many of either product were made, the pairing demonstrates that LEGO’s material transition was not an abrupt switch.

LEGO’s historical index groups wooden toys under 1932–1959 and early plastic products under 1949–1958. Those categories overlap for approximately a decade. The collector account extends wooden-toy manufacture through 1960, but the one-year difference cannot be resolved from the accounts themselves. They may use different definitions of an endpoint, such as production, catalog classification, inventory, or the closure of a workshop, but none specifies the reason for the discrepancy.

What matters is the shared conclusion: wooden toys remained part of LEGO’s business after plastic products appeared. Plastic initially expanded the company’s manufacturing vocabulary rather than immediately replacing everything it had previously made. LEGO’s product-history chronology presents a wooden period and an early plastic period that overlap rather than follow one another in a clean sequence.

The 1942 Workshop Fire and Continuity of Production

A third-party collector history reports that fire damaged LEGO’s workshop in 1942. It places the event within the company’s wooden-toy era and indicates that wooden-toy production continued afterward.

The fire was a significant disruption, but the collector account does not provide a detailed operational record. It does not establish the full extent of the losses, the rebuilding schedule, financing or insurance arrangements, staffing changes, or the precise effect on production.

What can be said is that the fire did not end LEGO’s wooden-toy history. The production ranges described by LEGO and the collector publication extend into the 1950s, while the wooden bus dated 1949 provides an object-specific example from seven years after the reported workshop damage. That continuity does not mean the event was minor; it means wooden products remained part of the company’s operations after it.

The fire also should not be recast as the invention story of the plastic brick. LEGO’s first injection-molding machine arrived several years later, and neither the corporate history nor the collector account says that workshop damage caused the company to buy it.

The same restraint applies to broader wartime explanations. These accounts do not connect LEGO’s investment to a specific government policy, material shortage, occupation measure, or other particular World War II condition. The defensible sequence is narrower: a workshop fire occurred during the wooden-toy period, wooden products continued afterward, and LEGO later added plastic processing.

1947–1948: LEGO Learns to Manufacture in Plastic

According to LEGO, its first plastic injection-molding machine arrived in late 1947. The equipment was initially tested in the basement of Godtfred Kirk Christiansen’s home and then installed in a building next to the woodworking factory.

That physical placement captures the nature of the transition. The molding machine did not arrive after the woodworking operation had disappeared; it was installed beside it. LEGO was adding a production process to an existing business.

It opened the possibility of manufacturing multiple kinds of plastic toys, not only building blocks. LEGO’s account does not provide the machine’s purchase price, output, tooling specifications, molding pressure, tolerances, or production capacity, so a more technical reconstruction would be speculative.

The chronology is clearer than the business rationale:

1. Late 1947 was the capability milestone. LEGO obtained, tested, and installed its first injection-molding machine.
2. 1948 was the learning period. Employees experimented with plastic molding and became more familiar with the process.
3. 1949 was the first documented commercial-product year. LEGO introduced several plastic toys, including its first plastic building blocks.

This sequence prevents two common misunderstandings. First, receiving the machine did not mean a completed building system appeared immediately. Employees spent time learning how to work with plastic before products reached the market. Second, the equipment did not turn LEGO overnight into a brick-only company. It supported a wider plastic range while the woodworking business remained active.

The distinction between manufacturing capability and commercial product is central to the decade. Equipment can make new forms possible, but it does not determine which forms a company will select, how effectively it will produce them, or how customers will respond. LEGO’s work during 1948 occupied the space between acquiring a technology and releasing products made with it.

Automatic Binding Bricks: LEGO’s 1949 Plastic Building Set

In 1949, LEGO introduced Automatic Binding Bricks as its first plastic building blocks and the basis of its first plastic building set. They appeared among several kinds of plastic toys made by the company that year, rather than as its only experiment with the material.

Yet the pieces should not be treated as modern LEGO bricks with an earlier label. Their material, underside, side openings, and initial lack of branding mark them as predecessors.

The unsigned archived Technica account describes the blocks as made from cellulose acetate. They had round studs on top, slits in the sides, and hollow undersides. The side openings could accept components such as window or door panels. The same account says the earliest examples carried no identifying marks and places the addition of LEGO lettering to the underside around 1950.

Feature	Automatic Binding Brick
Material	Cellulose acetate
Top	Round studs
Sides	Slits intended to accept elements such as window or door panels
Underside	Hollow
Branding	Earliest examples reportedly unmarked; LEGO lettering added underneath around 1950
Launch year	1949
Initial market	Denmark

The archived account also traces the side-slit concept to Kiddicraft, making it a feature adopted from the earlier British design rather than one first introduced by LEGO in 1949.

The hollow underside is particularly important when distinguishing these pieces from later LEGO bricks. A block can look recognizably LEGO-like from above because it has round studs while differing substantially beneath them. Top studs alone do not define the mature element or its role in the later building system.

The available accounts do not provide exact dimensions, measured clutch power, production tolerances, comparative durability, or a technical demonstration of full compatibility with present-day elements. Identifying cellulose acetate as the material also does not establish the present condition of every surviving block; age, storage, and production variation could affect individual examples.

That description recognizes their place in the company’s history without projecting later engineering and system development backward into 1949.

Kiddicraft and Hilary Fisher Page: The Earlier Brick Behind LEGO’s Design

Hilary Fisher Page was the British inventor associated with Kiddicraft Self-Locking Building Bricks. The secondary account dates his British patent to 1940, nine years before LEGO marketed Automatic Binding Bricks, and describes the Kiddicraft product as a hollow rectangular plastic block with four round studs on top. Later Kiddicraft improvements reportedly included side slits for inserting window or door panels.

This chronology establishes an essential distinction: the earlier patented studded plastic block was a Kiddicraft development, not a LEGO product. Page’s patent was not a LEGO patent, and 1940 was not the beginning of LEGO brick production.

LEGO acknowledges the British product’s influence. Its corporate history says Ole Kirk Kristiansen and Godtfred Kirk were shown plastic cubes from a British manufacturer in the late 1940s. It identifies Page and Kiddicraft as the inventors of those bricks and says LEGO “redesigned” the cubes before launching Automatic Binding Bricks.

The archived enthusiast page uses stronger language, characterizing LEGO’s blocks as nearly exact copies. That is the unsigned page author’s interpretation, not a conclusion demonstrated by a documented feature-by-feature comparison. Conversely, LEGO’s use of the word “redesigned” does not reveal which features were changed. The two accounts establish influence and adaptation but do not define the exact scope of the prelaunch modifications.

The archived page also says Kiddicraft drawings and samples reached Ole Kirk in 1947, attributing the assertion to later court testimony. That attribution is important. Later testimony can preserve historical information, but it is not the same as an independently examined delivery record created in 1947.

Four questions are often conflated:

1. Who invented the earlier studded plastic block? Page and Kiddicraft are associated with the earlier patented Self-Locking Building Brick.

2. What did LEGO adapt? LEGO’s early product drew on the British cubes, including their recognizable studded form and features such as side slits.

3. How did LEGO commercialize its version? LEGO used its new molding capability to market Automatic Binding Bricks as a Danish building set.

4. When did LEGO acquire the later rights? LEGO says it purchased the Kiddicraft brick and trademark rights from Page’s descendants in 1981.

Keeping those questions separate avoids two opposing errors. One is to erase Page and present the studded plastic block as a wholly independent LEGO invention. The other is to assume that visual similarity settles every issue involving redesign, commercialization, consent, or legal rights.

LEGO’s first plastic building blocks were indebted to Kiddicraft, and LEGO manufactured and marketed its own version. The exact extent of its prelaunch redesign remains unclear.

A Modest Danish Launch, Not an Instant Global System

LEGO says Automatic Binding Bricks and its other toys were sold exclusively in Denmark at the time. The 1949 release was therefore geographically limited when compared with the company’s later international reach. The account does not explain why distribution remained domestic, so no particular strategic, financial, technical, or logistical reason can be assigned.

The commercial reception is also difficult to measure. LEGO calls the bricks “relatively successful” but supplies no sales totals, production quantities, dealer figures, or return rates. The unsigned archived page reports limited distribution and returned sets, likewise without quantities.

Taken together, these descriptions support a bounded conclusion: the bricks found some market, but the accounts do not establish either a major commercial success or a commercial failure. Qualitative wording cannot responsibly be converted into sales statistics.

LEGO adds that the Ferguson Tractor, introduced in the fall of 1951, became its best-selling plastic toy of that period. The comparison helps place the bricks within a broader early plastic range. Their later historical importance does not prove that they immediately dominated the company’s sales.

The English product name introduces another evidentiary distinction. LEGO says “Automatic Binding Bricks” honored the Allied forces that liberated Europe and ended World War II in 1945. Its corporate page does not reproduce contemporary naming documents, so this remains LEGO’s retrospective explanation rather than an independently confirmed account from the launch period.

The modest scale of the release does not diminish its historical importance. In 1949, LEGO moved from experimenting with plastic to marketing an interlocking building product. It had, however, entered the plastic-building-block business.

Historical consequence and immediate commercial scale are not the same. A Denmark-only product could become a significant beginning even when its initial distribution was limited and its sales performance remains unquantified.

What Changed After 1949—and What Remains Unresolved

A version made around 1950 reportedly added the LEGO name to the underside, addressing the lack of identifying marks on the earliest examples. “Around 1950” should not be converted into a precise production day, batch, or universal change without more detailed records.

Wooden-toy production continued as LEGO’s plastic range developed. LEGO ends its wooden-toy historical grouping in 1959, while the collector account gives 1960. The discrepancy remains unresolved, but both chronologies confirm that the two material categories coexisted for years.

The Kiddicraft relationship also has a later corporate history. LEGO says it contacted Kiddicraft in the late 1950s and was told there was no objection to the LEGO brick. The corporate page does not reproduce correspondence documenting that exchange, so it should not be treated as demonstrated formal approval.

LEGO further says that it purchased the Kiddicraft brick and trademark rights from Page’s descendants in 1981. The company reports both the late-1950s contact and the later transaction in its account of the relationship. The timing alone does not establish why the purchase occurred.

Documented in the published accounts

• LEGO says its first injection-molding machine arrived in late 1947.
• LEGO says employees developed molding experience during 1948.
• Automatic Binding Bricks appeared in 1949 among several plastic products.
• LEGO says its toys were then sold exclusively in Denmark.
• Both the LEGO account and the archived enthusiast page acknowledge Kiddicraft’s influence.
• LEGO’s wooden and early plastic product periods overlapped.

Still unresolved

• The exact design changes LEGO made before launch.
• Production, sales, return, and unsold-inventory totals.
• The reason distribution was limited to Denmark.
• The precise date and scope of the first underside branding.
• Technical compatibility with later bricks.
• Contemporary documentation for LEGO’s explanation of the English name.
• Documentary confirmation of the reported late-1950s conversation with Kiddicraft.
• The reason the Kiddicraft rights were purchased in 1981.
• The cause of the 1959–1960 difference in wooden-toy end dates.

These distinctions are part of the history, not minor cautions around it. LEGO’s corporate recollection establishes what the company says about its past. A collector guide provides information about wooden objects and traditions. An unsigned enthusiast page preserves physical descriptions and interpretations. Later testimony reports earlier events. Patents, catalogs, correspondence, business records, and surviving objects would answer different questions and should not be treated as interchangeable forms of proof.

The central conclusion remains clear. LEGO’s development during the 1940s was defined by coexistence rather than immediate replacement. Wooden ducks, vehicles, and buses remained part of its story while employees learned injection molding. Automatic Binding Bricks began LEGO’s plastic-building future, but they were an early, geographically limited product indebted to Page’s Kiddicraft design.

The decade marked a beginning—not the instant appearance of the mature modern brick, a finished worldwide system, or a plastic-only LEGO company.

Frequently Asked Questions

What was LEGO’s first plastic building brick?

LEGO’s first plastic building block was the Automatic Binding Brick, introduced in 1949 as the basis of its first plastic building set. It appeared alongside other plastic toys rather than as the company’s only new plastic product.

The early block was reportedly made from cellulose acetate and had round top studs, side slits, and a hollow underside. The earliest examples reportedly lacked identifying marks.

Did LEGO invent the first studded plastic building block?

Not according to either LEGO’s account or the archived independent history. Hilary Fisher Page’s Kiddicraft Self-Locking Building Brick preceded LEGO’s version.

LEGO acknowledges that the British plastic cubes influenced Automatic Binding Bricks and says it redesigned them. The accounts do not identify the exact changes, so they support neither wholly independent invention nor a definitive conclusion that the products were identical in every respect.

Were Automatic Binding Bricks the same as modern LEGO bricks?

No. They were predecessors of the modern LEGO brick, not the same mature element.

They were reportedly made from cellulose acetate, had hollow undersides and side slits, and initially carried no LEGO marking. The accounts do not establish identical dimensions, modern compatibility, comparative clutch power, or equivalent durability.

Did LEGO stop making wooden toys when it introduced plastic bricks in 1949?

No. LEGO’s history identifies a wooden single bus from the same year and presents wooden toys and early plastic products as overlapping categories. LEGO dates its wooden-toy grouping through 1959, while the collector publication gives 1960.

The one-year discrepancy is unresolved, but both accounts show that wooden-toy production continued after plastic products appeared.

Where were LEGO’s first plastic building sets sold?

LEGO says Automatic Binding Bricks and its other toys were sold exclusively in Denmark at the time. The initial release can therefore be described as geographically limited.

The company’s account does not explain the reason for that restriction, and neither principal account provides documented production or sales totals.

LEGO’s future in plastic began while saws, wood, and wooden toys were still part of the business. That overlap—not an overnight conversion—is the defining fact of its 1940s history.