Why Are There so Many Types of Screws?!

Summary

In this video, the evolution of the screw is explored, from its humble beginnings with Archimedes' helical design to the widespread adoption of various screw types. The history touches on the development of mass manufacturing techniques, the rise of the slotted, Robertson, and Phillips screw designs, and the advent of more modern types like Torx and hex screws. The video humorously delves into the frustrations of dealing with incompatible screwdrivers, while also offering a deeper understanding of screw technology and its impact on engineering and manufacturing. It also touches on the global difference in measurement standards and the complexities of modern fasteners.

Takeaways

• 😀 The episode is sponsored by CuriosityStream, offering 31 days of free access to over 2,400 documentaries.
• 😀 The video humorously explores the excitement and confusion of choosing screws at a hardware store.
• 😀 The invention of the screw is often credited to Archimedes, who used it to pump water, though he may have borrowed the idea from the Egyptians.
• 😀 A screw's basic mechanism is based on a wedge shape that applies force along its length, which was historically used for tasks like water pumping and pressing grapes.
• 😀 The modern screw, designed for holding parts together with opposing forces, became widely popular only after mass manufacturing techniques were developed in the late 18th century.
• 😀 Henry Maudsley's invention of the metal cutting lathe in 1797 allowed for precise, consistent screw threads, which led to standardization and the creation of reliable screws.
• 😀 A historical screw design conflict is highlighted by the Boston Fire of 1872, when mismatched fire hoses and hydrants caused problems due to varying thread standards.
• 😀 The ISO metric system is the global standard for screw threads, though the United States still uses inch-based measurements.
• 😀 Early screw designs like the slotted screw were cheap to make but prone to issues with screwdriver slippage, prompting the development of new head designs.
• 😀 Peter Lymburner Robertson’s square screw head design prevented slippage and was used in Ford’s Model T, saving time during manufacturing.
• 😀 Henry F. Phillips introduced the Phillips screw head, which was self-centering and limited torque to prevent over-tightening, becoming widely used in automotive and other industries by the 1940s.
• 😀 Newer screw designs like Torx and hex screws were created to prevent the ‘cam-out’ problem, offering better torque application and reducing damage to both tools and screws.
• 😀 Despite being initially designed to restrict access to devices (like Apple’s first personal computer), Torx screws became more common due to their effectiveness in preventing cam-out.
• 😀 The rise of complex screw designs and the introduction of pin-centered screws have led to more challenges for DIY repairs, often complicating the ability to fix gadgets.
• 😀 The video ends with a lighthearted reference to squirrels and promotes a documentary on CuriosityStream about squirrels, along with a documentary about the race to the moon.

Q & A

Who is credited with inventing the screw?

The screw is believed to have been invented by Archimedes, who used its helical design to pump water, although he likely borrowed the concept from the Egyptians.

What is the basic mechanism behind how a screw works?

A screw works by using a wedge shape that spirals upwards, turning rotational motion into linear force to lift or move objects.

What were some of the early uses of the screw?

Screws were used for various purposes, including pumping water, digging holes, and pressing grapes to make wine.

What significant innovation helped screws become more widely used?

Henry Maudsley’s invention of the metal cutting lathe in 1797 allowed for precise and consistent cutting of screw threads, enabling mass production.

Why was there so much confusion around screw standards in the past?

The lack of standardization in screw threads led to incompatibilities, such as the well-known issue during the 1872 Great Boston Fire when different fire hose threads didn’t match the fire hydrants.

What screw thread system is now commonly accepted around the world?

Most of the world uses the ISO metric thread system, which is based on the metric measurement standard. However, the US still predominantly uses the inch system.

Why is it difficult to find just one type of screw head design?

Different screw head designs have been created to address various practical needs, such as preventing slipping, improving torque application, and allowing for mass production. This results in a variety of designs, like slotted, Robertson, Phillips, and Torx.

What was the first screw head design and why was it problematic?

The slotted screw head was the first design, but it was prone to slipping, making it difficult to use with a screwdriver, leading to issues like misalignment and damage to the material being fastened.

How did Peter Lymburner Robertson's screw design improve upon earlier models?

Robertson's square bit screw head design was created to be easily driven without slipping, preventing screwdriver slippage and ensuring better alignment and efficiency in manufacturing.

What was the key feature of the Phillips screw design?

The Phillips screw design has a conical cross shape that self-centers, prevents over-tightening, and allows for easier insertion, though it can still be difficult to remove once rusted.

What are Torx and hex screws, and why are they considered improvements over Phillips screws?

Torx and hex screws have designs that prevent the screwdriver from slipping (known as 'cam-out') and allow for more torque to be applied without damaging the screw. Torx screws are particularly known for their strong, consistent torque transfer.

Why were Torx screws initially used in Apple products?

Torx screws were used in early Apple products to prevent users from easily opening the device, adding a level of security against tampering or unauthorized repair attempts.