Screws are used to fasten materials by the engagement of the screw thread with a similar female thread in the matching part, actually, screws are often self-threading, which means that when you turn a screw into the material, the thread will cut into the part and create an internal thread to fasten materials together.
Here is a group of common types of screws with their structures, features, and applications. Guide for more types of fasteners is published on our site. Wood screws are a type of screw with a smooth shank and tapered point used for wood or other soft materials. There are many types of wood screws based on different screw heads, including Phillips flat head screw, Frearson flat head screw, slotted flat head screw, slotted oval head screw, Phillips round head screw, and slotted round head screw.
The round head wood screws are suitable for attacking thin materials to wood, the flat head wood screws are ideal for securing hinges. Wood screws are often made from stainless steel or brass. Machine screws usually are smaller than the average screw and designed with finer, more accurate threads than other fasteners, they are intended to be fastened to an existing tapped hole on the surface of metal parts in various machinery or in conjunction with a corresponding nut.
The use of machine screws can be found in machines of all kinds of industries, including manufacturing, engineering, machine tool, and more. They can be used in almost every material such as brass, steel, and nylon. Machine screws also have a wide variety of head types, including Phillips, slotted, star drive, combo, flat, pan, oval, and truss, these head types can form a number of combinations.
A sheet metal screw consists of a fully threaded shank with sharp threads and a tip, and a head. Full threads can increase retention between materials and the sharpness allows it to cut into the material and form its own internal thread easily. Sheet metal screws are often used to fasten metal parts to metal parts, or attach metal pieces to plastic, wood, rubber, or other materials. Sheet metal screws can be classified into self-tapping screws and self-drilling screws.
Self-tapping sheet metal screws have a sharp tip to fasten metals with pre-drilled holes, while self-drilling screws can cut through metals that have not been drilled with their drill point tip. Socket screws are also known as Allen head screws, designed with a hexagonal internal drive built into the head and required to be tightened or loosened with an Allen wrench or hex key.
This feature sets socket screws apart from other types. Sheet metal screws can fasten or connect two pieces of sheet metal together to tubing or other metal types. There are different types of sheet metal screw heads available including flat, hex, and round. These slotted screws are made from pure steel with a weather-proof coating of stainless steel or aluminum. They are most commonly used in welding industries. These screws are mainly used for softer materials , such as wood, plastic, or nylon.
Their double lead thread style minimizes torque and enhances pullout power. This prevents the material from cracking or damage. There are some thread-rolling screws that also feature widely-spaced threads that make them easier to insert into pre-drilled holes.
These types of screws are highly strong and reliable wherever a joint is required. They are also exceptionally resistant to corrosion. But aside from their sturdiness, they ensure an attractive and quality finish. Set screws are used to fasten an object to or against another object.
For example, a gear or pulley can be secured to a shaft using a set screw. These screws are fully threaded without a head sticking out, and there are many different shapes and sizes available. Weld screws are welded to an aluminum or metal surface to create a shaft for the components that are to be fitted or fastened. This can be done using a washer or nut.
The tabs of weld screws extend from the head in order to allow welding without using a hole. The welding stud is then fastened to a metal piece. These types of screws are most frequently used in the automotive, industrial, marine, construction, cookware, and aerospace industries.
Slotted cheese head screws are made from stainless steel and are designed with a round, raised head. These screws are highly popular in industrial, electrical, telecommunication, and automotive lighting applications due to the fact that they are extremely rust and corrosion-resistant and can be used in underwater projects. Fillister head screws are slotted head machine fasteners with a large over-sized head that can be used for attaching metal or wood to metal.
Also referred to as cheese head screws, the fillister head fasteners are similar to pan head machine screws but with a bigger side height. The head of these screws are mainly preferred for counterbored holes. Drywall screws are standard fasteners for securing partial or full sheets of drywall to wall or ceiling joists. There are two types of drywall screws available. These are:. Coarse : this type of drywall screw is mostly used for wood studs. The widely arranged threads are effective in gripping into the wood.
Drywall screw also features an extra sharp tip and a phosphate finish. Fine : this type of drywall screw is self-threading, thus making it perfect for metal studs. The fine drywall screws have double threads for easier and more practical self-starting. Concrete screws come in all kinds of head designs, from flat and pan to slotted hex.
The pan and flat head screw styles can be flush to the surface of the material to make it look nicer, while a hex-head slotted screw is easier to drive in. Because of the high-low threading design of these screws, they provide durable and solid results in attaching to concrete or stone. Machine screws are used to hold parts of machines in all kinds of industries, such as electronics, engineering, and manufacturing equipment.
These screws are specifically designed to fasten to a tapped hole on a surface with the help of a nut. Their blunt ends are used to attach metal parts together. Machine screws can be found in almost every material including nylon, brass, stainless steel, and carbon steel. Modified truss screws are the self-tapping varieties that are also known as round washer head or wafer head.
They are used in numerous industries, from HVAC to sheet metal and woodworking. You can also use them for simple metal or aluminum framing tasks.
Washer-faced screws come in several types of washers that act as springs to reduce the distance between the head of a nut and bolt. In addition to their spring feature, some washer-faced screws have teeth that penetrate into the surface and lock the screwhead to the workpiece. These screws are also known as shaker-proof lock washers with twisted out teeth. This will avoid the material from getting trapped inside the device. The role of thread-cutting screws is to minimize the creation of internal device stresses, thus making them ideal for extremely stiff materials.
This is in contrast to a thread forming screw, whose edge does not have any cutting, which makes it difficult in materials with low compressive strength force. But this forms a tight bit between the thread forming screw and the material. Self-drilling screws come in different lengths of drill tips. The highest number is equal to a longer drill tip.
You also have the option of choosing different point sizes based on their diameter. Self-drilling screws also have a variety of uses and types and are mainly used for fastening or joining sheet metal or steel to other metals. Self-tapping fasteners tap their own thread, hence the name.
The threads of the screw will dig into the wood and keep it secure. Self-tapping screws can, in fact, be used in all kinds of materials like metal and brick, not just wood. For harder surfaces, it may be best to choose the self-tapping screws that have pointed tips on their thread in order to cut into the material.
However, not all self-tapping screws have pointy tips; some will be flat or blunt so make sure you choose the right one for your specific application. Framing screws are multi-use fasteners for sheet metal, wood, laminate, composite decking, and cement fiber board applications. These screws are designed to countersink into many different materials, from hardwood flooring to brittle composite. Framing screws work very similarly to circular saw blades as they prevent the sawdust from getting to the edge of the screw hole.
The hole can then be sealed off without damaging the surface of the material. Tamper-proof screws are suitable for use in buildings or areas that are accessible by the public to prevent or deter vandalism. Flat head screws have varying degrees. The degree of a flat head refers to its had angle or the angle from the top of the head to the surface where the threaded part meets the head.
An degree flat head is the standard angle, but there are also degrees, degrees, and more. A higher degree requires a shorter, but more spread out, countersink hole. A flat undercut degree head has the same angle as a standard degree head, but the head is much shorter. This head shape helps give the screw a longer thread on the same screw length because of its shorter head size. Raised heads, sometimes known as oval-shaped heads, have an angle much like flat screws but have more of a dome-shaped head.
Unlike a flat screw, the head of a raised screw will come out of the surface slightly. Binding screws are a unique type of screw that you can use for a range of projects. These screws have a slightly domed head and screw into each other with a male and female side. Often, short binding screws can hold together large manuals and other bookbinding projects, but you can also use them to hold together swatches, leather, and more. The dome shape creates a visually appealing design on the surface, while the flat inner part of the dome helps the screw stop where it needs to just at the surface.
The head of these screws can vary from circular to hexed, and it juts out from a circular flange directly underneath the head. The flange helps the screw to remain in its position, taking the place of a washer for some projects. Truss heads are typically wider than the heads on other screws and have a slightly rounded surface.
You can always find this out by looking at the head. Your project is also something to take into consideration.
Do you mind if a rounded head protrudes from the surface, or would you rather have a smooth finish from a flat screw? The drive is directly related to how the screw attaches to a surface. Some drives are better at avoiding stripping, which renders a screw useless, than others, but may also cost more money and be more difficult to find tools for.
External hex screws have a hexagonal head shape that protrudes from the surface. Some have built-in flanges, whereas others only have the hexagon shape as the full head. You can get good leverage on these screws since you turn the full head, rather than just an internal portion of the head.
See more about hex bolts here. A Phillips screw is one of the most common. This screw has a cross-shape that helps self-center the screw to avoid it drilling at odd angles.
You can also use a drill with a Phillips screw because its self-centering design allows it to remain in place when you apply force from a drill.
However, too much force can strip the head quickly. Pizodrive screws look similar to the Phillips shape, except that they have a few more grooves in them that create a shape resembling a star. You can tell the difference between a Pozidrive and Phillips screw by looking at them from the side.
The Quadrex head drive, also known as a Phillips square drive, is a combination of Phillips and square recess. It looks much like the Phillips design, except that the middle of the cross shape is squared rather than pointed, which can help prevent stripping when you apply more force. Slotted head screws are what most people refer to as flathead screws, because they have one narrow opening for a flat screwdriver.
In fact, slotted screws are supposed to strip , by design, to prevent you from overtightening them. Slotted screws are best for projects that require a few screws that you can screw manually, rather than with a powered drill, which will often cause the screw to strip or cam out.
These have a square center point that prevents cam outs.
0コメント