The screw is the case of the inclined plane, with the length of one convolution of the thread being the length of the corresponding inclined plane.

Screw

The screw is the case of the inclined plane, with the length of one convolution of the thread being…

An illustration of a screw, which is incline plane wrapped around a cyclinder.

Screw

An illustration of a screw, which is incline plane wrapped around a cyclinder.

An illustration of a screw, which is incline plane wrapped around a cyclinder.

Screw

An illustration of a screw, which is incline plane wrapped around a cyclinder.

"Power is applied to the head of the screw. Each time the screw is turned into the nut, it advances the distance between two of the threads and compresses to that extent any fixed object against which it is directed." —Quackenbos 1859

Screw and Nut

"Power is applied to the head of the screw. Each time the screw is turned into the nut, it advances…

"In this, the screw is fixed, while the nut, N, by being turned by the lever, L, from right to left, will advance down the screw." -Comstock 1850

Screw Fixed Screw

"In this, the screw is fixed, while the nut, N, by being turned by the lever, L, from right to left,…

An illustration showing how to construct a screw helix.

Construction Of A Screw Helix

An illustration showing how to construct a screw helix.

"A screw is a cylinder, generally made of wood or metal, with a spiral ridge (the thread) winding about its circumfrence. The thread works in a nut, withihn which there is a corresponding spiral groove to receive the thread." -Avery 1895

Screw press

"A screw is a cylinder, generally made of wood or metal, with a spiral ridge (the thread) winding about…

An illustration of a screw press which is a type of machine used to shape or cut metal.

Screw Press

An illustration of a screw press which is a type of machine used to shape or cut metal.

"The power is generally applied by a wheel or a lever, and moves through the circumfrence of a circle. The distance between the two consecutive turns of any on continuous thread, measured in the direction of the axis of the screw, is called the pitch of the screw." -Avery 1895

Screw with Lever Arm

"The power is generally applied by a wheel or a lever, and moves through the circumfrence of a circle.…

Allen headless set screw is a hex socket screw used to fasten two objects.

Allen Headless Set Screw

Allen headless set screw is a hex socket screw used to fasten two objects.

A collar screw is used as mechanical stops, locating components, and bearing faces. The screw is commonly found in machines, usually in power transmission, motors, and gearboxes.

Collar Screw

A collar screw is used as mechanical stops, locating components, and bearing faces. The screw is commonly…

An illustration of the V thread screw. The screw is drawn by connecting the two opposite points of the thread to create the required pitch.

Conventional V Thread Screw

An illustration of the V thread screw. The screw is drawn by connecting the two opposite points of the…

The shaping machine used to cut triple threads on a screw viewed from a lengthwise axial section.

Cutting Triple Worms Screw

The shaping machine used to cut triple threads on a screw viewed from a lengthwise axial section.

"That the screw is a modified inclined plane, may be shown by winding a triangular piece of paper around a cylinder." — Avery, 1895

Diagram of a screw

"That the screw is a modified inclined plane, may be shown by winding a triangular piece of paper around…

A diagram illlustrating the principal of the screw.

Diagram of a Screw

A diagram illlustrating the principal of the screw.

A double thread screw drawn by drawing diagonal lines in between the pitch. The double thread screw is a screw with threads bunched together between the pitch.

Double Thread Screw

A double thread screw drawn by drawing diagonal lines in between the pitch. The double thread screw…

Drive screw is a threaded fastener used in industrial application. The screw is designed to last long by having a strong and durable head.

Drive Screw

Drive screw is a threaded fastener used in industrial application. The screw is designed to last long…

The lag screw is used in fastening heavy timbers with a square or hexagonal head.

Lag Screw

The lag screw is used in fastening heavy timbers with a square or hexagonal head.

Illustration of a common representation for square thread screw. The screw is drawn in two dimensions and used in drafting plans and mechanical drawing.

Square Thread Screw Mechanical Drawing Representation

Illustration of a common representation for square thread screw. The screw is drawn in two dimensions…

A hardened thread, that forms its own internal thread when driven into a relatively soft material (such as sheet metal)

Self Tapping Screw

A hardened thread, that forms its own internal thread when driven into a relatively soft material (such…

A close up of a square thread on a screw. This representation shows the correct an accurate three dimensional view of the screw.

Square Thread Screw

A close up of a square thread on a screw. This representation shows the correct an accurate three dimensional…

The screw cutting device is used to create thread on a lead rod.

Universal Screw Cutting Device

The screw cutting device is used to create thread on a lead rod.

Screw-and-Worm gearing is a type of gearing in which the velocity ratio is independent of the radii of the pitch surfaces, the teeth of the wheels essentially being portions of screw surfaces. This kind of gearing is used in speed-reducing arrangements.

Screw-and-Worm Gearing

Screw-and-Worm gearing is a type of gearing in which the velocity ratio is independent of the radii…

"A self-acting screw-cutting lathe with double-geared headstock, of a type now well established, the arrangements for obtaining and varying this traversing motion may be observed. A steel leading screw runs along the front of the lathe bed, and with it the slide rest can be connected at pleasure. Two or more change wheels, properly proportioned as to the number of their teeth, connect the head of the screw with the hinder end of the mandrel." —The Encyclopedia Britannica, 1903

Screw-Cutting

"A self-acting screw-cutting lathe with double-geared headstock, of a type now well established, the…

"An apparatus for lifting heavy bodies a short distance." — Williams, 1889

Screw-jack

"An apparatus for lifting heavy bodies a short distance." — Williams, 1889

The type of an order of trees or brushes known as the Pandancae or Screw-pine order. They are natives of tropical regions, and abound in insular situations, such as the eastern Archipelago.

Screw-pine

The type of an order of trees or brushes known as the Pandancae or Screw-pine order. They are natives…

The Hunter's screw is formed of two screws, a larger and a smaller. The former being screwed internally to allow the latter to screw into it.

Hunter's Screw-press

The Hunter's screw is formed of two screws, a larger and a smaller. The former being screwed internally…

"The machine is in fact a lathe with a few special features, such as the hollow mandrel, which enables it to operate upon a bar of any length. Dies mounted on a modified form of slide-rest cut the thread to the full depth at a single traverse, and a simple arrangement enables nuts to be tapped with equal facility. In some other varieties of screwing machines, more particularly those intended for hand power only, the outward resemblance to the turning lathe is less apparent, but if their action is looked into it will be found that in them as in almost all machine tools it is the principle of the slide which is mainly conducive to their success." —The Encyclopedia Britannica, 1903

Screwing Machine

"The machine is in fact a lathe with a few special features, such as the hollow mandrel, which enables…

Round head and flat head screws compared.

Wood Screws

Round head and flat head screws compared.

A shoulder screw, also known as stripper bolt, is a fastener where the thread ends at the larger diameter. The screw usually used in machinery.

Shoulder Screw

A shoulder screw, also known as stripper bolt, is a fastener where the thread ends at the larger diameter.…

Illustrations showing the six mechanical powers: lever, wheel and axle, pulley, inclined plane, wedge, and screw.

Simple Machines

Illustrations showing the six mechanical powers: lever, wheel and axle, pulley, inclined plane, wedge,…

Single threaded screw.

Single Threaded Screw

Single threaded screw.

This illustration shows an example of a skew bevel gear.

Skew Bevel (gear)

This illustration shows an example of a skew bevel gear.

"The parts are the butt, A; small, B; magazine well, C; barrel bed, D; air chamber, E, which reduces the charring effect og a heater barrel on the stock; small butt plate screw hole and seat for the butt plate tang, F; butt swivel plate seat, G; mortise for receiver tang lug and hole for rear guard screw, H; mortise for sear and slot for trigger, I; cut-off thumb-piece recess, J; mortise for recoil on the receiver, K; bed for fixed base, L; grasping grooves, N; shoulder for lower band, O; bed for band spring, P; shoulder for upper band, Q; channels for decreasing weight, R; upper band screw hole, S; and the stock screw hole, T. The large hole in butt is for decreasing weight, and the smaller one is a pocket for the combination oiler and thong case." — Moss, 1914

Stock, right side view

"The parts are the butt, A; small, B; magazine well, C; barrel bed, D; air chamber, E, which reduces…

"The parts are the butt, A; small, B; magazine well, C; barrel bed, D; air chamber, E, which reduces the charring effect og a heater barrel on the stock; small butt plate screw hole and seat for the butt plate tang, F; butt swivel plate seat, G; mortise for receiver tang lug and hole for rear guard screw, H; mortise for sear and slot for trigger, I; cut-off thumb-piece recess, J; mortise for recoil on the receiver, K; bed for fixed base, L; grasping grooves, N; shoulder for lower band, O; bed for band spring, P; shoulder for upper band, Q; channels for decreasing weight, R; upper band screw hole, S; and the stock screw hole, T. The large hole in butt is for decreasing weight, and the smaller one is a pocket for the combination oiler and thong case." — Moss, 1914

Stock, top view

"The parts are the butt, A; small, B; magazine well, C; barrel bed, D; air chamber, E, which reduces…

A square threaded tap or screw with three equal lengthed thickness. The stepped tap is used to fasten two materials together with unthreaded top.

Stepped Threaded Tap

A square threaded tap or screw with three equal lengthed thickness. The stepped tap is used to fasten…

The illustration detailing of a screw thread. Threads are created by drawing a cylindrical shape at a constant diameter. The pitch, length between the threads, is drawn along the cylinder at an angle.

Drawing Screw Thread

The illustration detailing of a screw thread. Threads are created by drawing a cylindrical shape at…

Triple threaded screw.

Triple Threaded Screw

Triple threaded screw.

Turnbuckle is a screw device to adjust the tension or length of ropes, cables, tie rods, and other tension system.

Turnbuckles

Turnbuckle is a screw device to adjust the tension or length of ropes, cables, tie rods, and other tension…

This pocket watch has a circular handle at the top of the watch allowing it to be attached to a waistcoat, lapel or belt loop using a chain. The screw in the handle is used to wind the watch .

Pocket Watch

This pocket watch has a circular handle at the top of the watch allowing it to be attached to a waistcoat,…

The wood screw used to fasten two pieces of wood together. Wood screws usually have unthreaded shank below the head.

Wood Screw

The wood screw used to fasten two pieces of wood together. Wood screws usually have unthreaded shank…

Flat head screw countersunk (set flush) into wood.

Wood Screw Countersunk

Flat head screw countersunk (set flush) into wood.

"1, Screw-wrench; 2, Tap-wrench; 3, Angle-wrench; 4, Tube-wrench; 5, Monkey-wrench for hexagonal and square nuts." — Williams, 1889

Wrenches

"1, Screw-wrench; 2, Tap-wrench; 3, Angle-wrench; 4, Tube-wrench; 5, Monkey-wrench for hexagonal and…