Proof stress

Hi All, I am looking at a material cert to find the 0.2% proof stress of the material. Trouble is, the field is empty but the cert gives a value for Yield stress. Are these one in the same thing? If not could someone explain them to me as I am rather confused by it. Thanks in Advance, RE: Yield Stress V 0.2% Proof Stress (Materials) 12 Nov 15 13:15 For certain materials such as low carbon steels in annealed conditions, yielding can be clearly seen in a stress-strain curve and it is even possible to define an upper and lower yield strength. For other materials there is not a clear transition from the elastic to the plastic region and it is in such cases that the 0.2% proof strength comes into play. It represents a stress level below which the material can be considered macroscopically elastic. This is a possible explanation for the information reported in your material certificate. RE: Yield Stress V 0.2% Proof Stress

The examples and perspective in this article may not represent a You may ( April 2012) ( A proof test is a form of Proof tests may be performed before a new design or unit is allowed to enter service, or perform additional uses, Applications of proof testing [ ] Industrial tooling [ ] Cranes and derricks are proof tested when called on for potentially dangerous load levels or high-valued cargoes. Turbomachinery [ ] An overspeed proof test involves physically running the machine at high speed up to the test speed. This may be done during manufacture as an initial proof test. Physical overspeed tests may be periodically undertaken on some machines to verify operation of the overspeed protection systems. Operation at speeds above the normal operating speed can greatly increase stress levels in rotating parts. Failing flywheels, rotors, etc. may present a shrapnel risk in case of a failure. Swords [ ] Historically, Pressure vessels [ ] Vessels which may be a failure risk, such as utility-scale water towers, chemical-handling equipment, Firearms [ ] A firearm's chamber and barrel become pressure vessels for brief periods. In firearm terminology, a proof test is a test wherein a deliberately over-pressured proofed (not proven). In many A "proof round" is an ammunition assembly designed to be used in proof testing; this can use a fixed Testing methodology [ ] For both small arms and heavy weapons, the gun is fired remotely and then examined; if undamaged, it is assumed to be safe...

Being under stress can cause your blood pressure to spike briefly. But researchers aren't sure whether stress can cause blood pressure to rise long-term. Experts do know that exercising 3 to 5 times a week for 30 minutes can lower stress. For people with high blood pressure, doing activities that help manage stress and improve health can help lower blood pressure. The body releases a surge of hormones when under stress. These hormones cause the heart to beat faster and the blood vessels to narrow. These actions increase blood pressure for a time. There's no proof that stress by itself causes long-term high blood pressure. But reacting to stress in unhealthy ways can raise blood pressure and increase the risk of heart attack and stroke. Behaviors linked to higher blood pressure include: • Drinking too much alcohol or caffeine. • Eating unhealthy foods. • Eating too much. • Not moving enough. Heart disease also might be linked to certain health conditions related to stress, such as: • Anxiety. • Depression. • Being cut off from friends and family. There's no proof that these conditions are directly linked to high blood pressure. But the hormones the body makes when under emotional stress might damage arteries. The artery damage might lead to heart disease. And symptoms of depression and anxiety might cause some people to forget to take medicines to control high blood pressure or other heart conditions. Stress can cause a steep rise in blood pressure. But when stress goes awa...