The stud and tube principle

Godtfred Kirk Christiansen's firm belief in the plastic brick and the LEGO® System in Play drives the company to search for a way to ensure just the right clutch power between the bricks. The LEGO System’s basic element needs improving in order to live up to the product idea and the company’s quality standard. All bricks up until this point are hollow, reducing the stability of constructed models and this generates complaints from the markets, and competitors are moving in.

The patent

At a meeting on January 23rd 1958, Godtfred Kirk Christiansen and head of the German sales office Axel Thomsen discuss possible solutions to the stability issue mentioned in feedback from the markets. Godtfred draw up several solutions on a piece of paper, among them the tubes we all know today. Combined, the studs and tubes create clutch power. Clutch power provides stability and endless possibilities for combining bricks. With the new stud and tube principle it is possible to combine six 2x4 bricks in 915.103.765 different ways. After inventing the tube solution, Godtfred Kirk is anxious. The ingenious interlocking principle has to be properly protected. On January 28, 1958 at 1:58 pm, the LEGO Group submits a patent application for “a toy building element”. The LEGO® brick as we know it today is born.

front of a LEGO box

Shortly after the patent application is submitted, the stud-tube principle is demonstrated on the outside of all new LEGO sets