Engineering Report Crane Hooks
Crane hooks
Today in this report I will explain how the forged hook is better compared to a cast hook. My reasons towards this decision are later discussed throughout this report.
Forging is referred to as the shaping of a metal through the use of compressive force; forging can be classified as hot or cold and will be explained later in the report.
Casting is referred to as when a liquid metal is poured into a desired mould, cooled then removed. Both of these manufacturing processes have their own benefits and downfalls, throughout my report it will discuss the pros and con’s to decipher which was the better metal to use will explain more below.
Engineers use a variety of tests to provide figures on mechanical properties to compare with other metals.
An important property throughout any sort of metal devices is strength. Strength refers to the materials ability to withstand a force without failure. Crane hooks carry great loads so must be able to withstand large forces. To test a materials strength engineers undergo as a tensile test. A machine stretches a sample of a desired material and then graphs their results on a stress/strain diagram
A normal steel stress/strain diagram
The red arrow indicates the ultimate tensile strength the maximum force this material could withstand without failure. To be safe engineers recommend the stress value at the elastic limit as the maximum allowable stress.
Tensile testing machine
Toughness is another important property, toughness is defined as how much energy a material can absorb before it breaks. Brittle metals have low toughness and that’s why they shatter easily.
Casting is done by pouring hot liquid metal into a mould of the finished product. There are many different processes of casting used in the industry, ranging from continuous casting to investment casting. The only main difference in casting methods is whether the fluid is forced into the mould by gravity or under pressure, for a denser
Today in this report I will explain how the forged hook is better compared to a cast hook. My reasons towards this decision are later discussed throughout this report.
Forging is referred to as the shaping of a metal through the use of compressive force; forging can be classified as hot or cold and will be explained later in the report.
Casting is referred to as when a liquid metal is poured into a desired mould, cooled then removed. Both of these manufacturing processes have their own benefits and downfalls, throughout my report it will discuss the pros and con’s to decipher which was the better metal to use will explain more below.
Engineers use a variety of tests to provide figures on mechanical properties to compare with other metals.
An important property throughout any sort of metal devices is strength. Strength refers to the materials ability to withstand a force without failure. Crane hooks carry great loads so must be able to withstand large forces. To test a materials strength engineers undergo as a tensile test. A machine stretches a sample of a desired material and then graphs their results on a stress/strain diagram
A normal steel stress/strain diagram
The red arrow indicates the ultimate tensile strength the maximum force this material could withstand without failure. To be safe engineers recommend the stress value at the elastic limit as the maximum allowable stress.
Tensile testing machine
Toughness is another important property, toughness is defined as how much energy a material can absorb before it breaks. Brittle metals have low toughness and that’s why they shatter easily.
Casting is done by pouring hot liquid metal into a mould of the finished product. There are many different processes of casting used in the industry, ranging from continuous casting to investment casting. The only main difference in casting methods is whether the fluid is forced into the mould by gravity or under pressure, for a denser
Bibliography: Engineering studies-the definitive guide by Paul L. Copeland http://www.certex.com/products/5.pdf http://en.wikipedia.org/wiki/Crane_(machine) http://www.ferret.com.au/t/Crane-Hooks Appendix Page 1- forging, casting, stress/strain diagram Page 2- forging, casting, tensile testing machine Page 3- conclusion, bibliography, appendix,