Scissors are handheld cutting tools. They are made of pivoted metal blades that consist of sharpened edges, which slide against each other when the handles move in opposite directions on an axis. Scissors are used for cutting thin material like cardboard, paper, cloth, rope, metal foil, and wire. Moreover, there are scissors for specific purposes that are sometimes referred to as shears. The blade angles reveals the difference in the types of scissors. For instance, Shaving scissors are not similar to the scissors used for cutting food or meat. It is believed that ancient Egyptians invented scissors in 1500 BC. Since the first scissors were found in Mesopotamia (McCain, Gillian, p 123).
Scissors are cutting tools that are expected to cut an object evenly. Since scissors are widely used, it is important to understand the various functions of the scissors to ascertain their effectiveness.
The sharpness of the blade: Sharpness is defined as the angle of cutting edge of a scissor. Ideally, the smaller the angle of cutting edge the sharper the scissor. However, the angle of the cutting has some disadvantage in that; the cutting edge is more unstable when the angle is more acute (Chen, Jin et al. p 519). Additionally, the Scissor can dull faster when the angle is more acute. Thus, the type and shape of cutting edge are important considerations during manufacturing of scissors. In addition to this, it is important to note that grinding the cutting edge at different angles depends on the final application of the scissors. Nonetheless, precision grinding which is performed microscopically eliminates any flaws on the edge of the scissors. In addition to this, a straight edge increase sharpness of the scissor compared to a ragged edge. Furthermore, the wedge shape of the cutting blade that allows the blade to glide magnifies sharpness of the scissor (Chen, Jin et al. p 520.).
Friction and Twist; technically, the blades of a scissor are in friction mode. The slight bowing of the blades of scissor creates the necessary friction between the blades, which implies that arching exists in the blades towards the inside of scissors. Moreover, both blades are turned towards the cutting edge on the inside, which implies that there is a twist. The twist and friction in the scissor create a force on the convergence point of the cutting edge that enables cutting (Chen, Jin et al. p 521).
During the cutting process, the material being cut tends to move forward when the blades move towards each other. Thus, the scissor can require a separate edge to prevent the material from falling. Moreover, it is important to note that the closing angle of the edge that cuts is approximately 21 degrees, which changes during cutting as the angle closes. Nonetheless, it is important to maintain an even cutting action for precision and consistent cutting angle.
The blade is made of metal, and it enables the scissor to cut material. Thus, without the blade, the scissor can be a piece of plastic handles held by a screw. The blade is designed such that the back of the blade goes into the handle and the sharper part protrudes outside.
The screw holds the parts of the scissor together. It acts as the blade pivot that enables them to move smoothly when cutting materials. Thus, the screw is an important part of the scissor.
The large handle is usually below the small handle and is where a person places their fingers to support the movement of the blade and facilitate cutting. Moreover, this handle is important because the screw goes through it to hold together the other parts of the scissors.
The small handle is where the thumb finger is placed; it holds one of the blades and aids in the up-down movement of the scissors to facilitate cutting ("Reverse Engineering Project").
As any other tool, the ease of use should be the main priority for the manufacturers. The tools should be comfortable and to use while making work easier for long hours without getting worn-out. The comfortability and ease of use can be achieved in the design shapes of blades and handles.
Shape of Blades
Due to the various applications of the scissors, many shapes of blades have been developed for a long time. For instance, scissors designed for cutting wick have an area for catching the wick after cutting; scissors for making huts are bent to accommodate the shape of the hat; scissors for wallpapering are designed so that they cannot be lifted from the cutting surface.
The handle should be designed such that the fingers are comfortable and make the scissor easy to use. Moreover, the shape of the handle should be smooth and follow the shape of the hand to make the scissor easy to use. Ideally, the larger the area for the finger and closer the shape of the scissor, the more comfortable and easy to use the scissor becomes and with more precision (Chen, Jin et al. p 523).
Chen, Jin et al. "Mechanical Analysis And Finite Element Simulation Of Scissor Transmission Mechanism Under Partial Load." KEM, vol 667, 2015, pp. 518-523. Trans Tech Publications, doi:10.4028/www.scientific.net/kem.667.518.
McCain, Gillian. "Scissors." Grand Street, no. 65, 1998, p. 123. JSTOR, doi:10.2307/25008346.
"Reverse Engineering Project." Antonio's Portfolio, 2016, http://antoniotenor.weebly.com/reverse-engineering-project.html.
If you are the original author of this essay and no longer wish to have it published on the SuperbGrade website, please click below to request its removal: