Steel is the most common material for spring washers due to its ease of process and its high tensile strength. Chrome vandium alloy is a higher quality steel with a good through-hardening capability; it is used to make very thick spring washers.
How to Prevent Swimmerâs Itch. Thereâs no cure-all to eliminate swimmerâs itch. The negative symptoms are, ironically, a problem of our own immune systemâs making, and short of abstaining from swimming altogether, thereâs a risk of getting swimmerâs itch in a Northern Michigan lake.
During aerobic exercise your body's demand for oxygen can be met and your intensity sustained. Any exercise you can maintain for more than two minutes will be aerobic. Aerobic swims are those that are longer in distance and duration. These swims are performed at an easy to moderate pace. Using the Borg Rating of Perceived Exertion scale, which measures physical intensity for a given effort on a scale of 6 to 20, an aerobic swim would fall somewhere between 7 and 13.