Screwdriver: A Comprehensive Guide

Table of Contents

What is a Screwdriver?

A screwdriver is a tool used to drive (or ‘turn’) screws into something. As you rotate the handle, you create a torque, turning the screw tip via the screwdriver’s shaft.

Screwdrivers are categorized by the shape of its tip, which fits the corresponding screw head (slots, recesses, etc.). Screwdriver tips come in a broad range of types and sizes - the most common ones are the ‘blade’ type for slotted screws and Phillips head, (‘cross-head’ or ‘cross-point’).

Nowadays, manual screwdrivers are replaced with a power drill, as they are easier to use and can also drill holes.

History of Screwdrivers

Unlike hammers, screwdrivers somehow remained indistinct throughout history, as the evidence of them was based primarily on the existence of screws.

The earliest screwdrivers are recorded in the late Middle Ages (e.g. the medieval manuscript Housebook of Wolfegg Castle), while the tool was more documented on shapes and sizes in France, yet only for slotted screws. More types appeared in the Gilded Age.

Screws were difficult to produce before the First Industrial Revolution - then the brothers Job and William Wyatt found a way to produce screws on a novel machine which greatly contributed to low-cost screw manufacturing, leading to popularity and diversity of screws.

Later, Peter L. Robertson, a Canadian inventor, became the first one to successfully commercialize socket-head screws.

Meanwhile, Henry F. Phillips patented his own screw with a crucifix intrusion, today known as Phillips Screw. After the Great Depression and World War II, Phillips screws became and remained one of the most popular screws in the world.

Application of Screwdrivers

The screwdriver is one of the crucial hand tools in any tool kit - their most common uses are:

Woodworking and carpentry
Mechanical and industrial production
Metalwork
Electronics and electrical equipment (mobile phones, computers etc.)
And many more.

There are also other screwdriver types such as application-specific or intended for particular industries.

Screwdriver Specifications

The three main parts of a screwdriver are:

Handle
Shaft/shank
Drive tip/bit

Handle

Screwdriver handles are typically wood, metal, or plastic and usually hexagonal, square, or oval in cross-section to improve grip and prevent rolling down. Handles can be ergonomic and covered in a non-slip material (e.g. thermoplastic rubber) to improve grip.

Shaft or Shank

Shafts or shanks are commonly made of strong steel and can be rounded or hexagonal to allow a spanner or wrench to be used for increased torque. The shaft is generally different material to the drive tip, which can be interchangeable.

Drive Tip or Bit

The drive tip can be either integrated into the shank or detachable. Alternatively, it can be an interchangeable part known as a driver. The tip is also known as the screwdriver head.

Types of Screwdrivers

Different types of screwdrivers are defined by the tip shape matching the specific screw head type.

Some of the most common types of screwdrivers are:

Phillips Screwdriver

Phillips screwdrivers (cross-head screwdrivers) are one of the most common ones. These screwdrivers are designed to fit Phillips screw heads with a cross-shaped recess, and are made for higher torsion.

Phillips screwdrivers come in several standard sizes, ranging from tiny "jeweller's" to those used in the automobile industry etc.

Slotted Screwdriver

The slotted screwdriver (aka. standard, common blade, flat-blade, slot-head, straight, flat, etc.) is used to drive a slotted screw head . Although there are many names, the original tool from 1908 was known as a "flat-head screw turner"

Robertson Screwdriver

Robertson screwdrivers are made to match Robertson screws, which have square-shaped sockets in screw heads. You can easily use them with only one hand, because the tapered socket tends to retain the screw, even if shaken. Robertson screws are common in Canada, though they have become more common in other countries recently.

Torx Screwdriver

Torx screwdrivers (aka. star head, pointed, six-point, and torque screwdrivers, etc.) correspond to the screw with six-point star-shaped heads, hence the name star screwdriver. These screwdrivers are made to ensure more torque like in mechanical production, for example.

Insulated Screwdriver

Safety or insulated screwdrivers are important for people working in potentially hazardous scenarios, e.g. electricians etc. They are made of non-conductive materials (e.g. rubber) to meet the necessary safety standards. There are also VDE screwdrivers with fully insulated blades.

Electric Screwdrivers and Impact Drivers

Electric or cordless (battery) screwdrivers are compact power tools great for simpler tasks like assembling furniture or screwing into softwood etc. Impact drivers are more heavy-duty, using sudden force to drive into or remove screws from harder materials.

Precision Screwdrivers

Precision screwdrivers are used for very small devices with extremely small screws. An example of this would be jewellers screwdrivers used for watches, mobile phones etc.

Other Types

Pozidriv Screwdriver

Pozidriv screwdrivers are essentially an upgraded version of Phillips screwdrivers only designed to prevent a screwdriver from slipping out of the screw head when more torque is applied.

Hex Screwdriver

Allen keys (wrenches) are made for hex screws to fasten bolts and screws - perfect for bike maintenance, furniture assembly and more.

Triangle Screwdriver

Triangle screwdriver heads are less common, but the design makes it more secure and tamper-proof than others. These tools are often used with appliances, toys, and electronics.

Magnetic Screwdrivers

Screwdrivers with magnetic tips allow screws to be attracted by magnetic force. This reduces the risk of accidentally dropping them. Magnetised tools are useful for working on electronics where screws are small and can be easily dropped into hard-to-reach places.

Ratchet Screwdrivers

Ratcheting screwdrivers have a mechanism allowing the tool to drive force only in one direction while moving freely in the opposite. These hand tools function similarly to ratchet spanners.

Screw Head Types

Since the evidence of screwdrivers was primarily based on the screws, here is a brief list on screw head types:

Slotted

Slotted screw head have a single line intrusion on its head, matching a ‘common blade’ or flat-bladed screwdrivers.

Some variations are coin-slot and hi-torque screw heads.

Cruciform

Cruciform screws are based on the crucifix or cross indentation shape. Variations include:

Cross
Phillips
Pozidriv
Supadriv
JIS B 1012
ISO 8764
Phillips II
Frearson
French recess
Torq-set
Mortorq

Square

Square screw heads or Robertson screws have a square-shaped indent in the screw head and a square protrusion on the tool.

Multiple square drives

Variations of square screw heads are multiple square and these include:

LOX-recess
Double-square
Triple-square

Internal Hex

Hex screw heads are recognizable by a hexagonal recess and correspond to a hex wrench, also known as an Allen wrench, Allen key, hex key, inbus or a hex screwdriver.
Variations include hex socket and double hex .

Pentalobular

Pentalobe screw heads are five-pointed and tamper-resistant. They are used in Apple products from MacBook to iPhone 4.

Aster recess is a variation made for the aerospace industry.

Hexalobular (Torx)

Hexalobular screws are characterised by a 6-point star-shaped pattern. Variations include:

Torx
Torx Plus
Torx Plus Tamper-resistant
Torx Paralobe
Torx ttap

Spline Socket

Spline socket screws have four or six splines - also known as Bristo, Bristol spline, fluted, multiple spline.

Combination

Certain screw heads are made to fit more than a single kind of driver, usually called combo-head. Variations include the most common ones like Slotted/Phillips and others like: