The calculator provide the force in manual clamping levers. A friction value will be assumed for the axis of rotation and the circumference of the eccentric. This friction values will have an important impact at the result of the clamping force.
The dew point can be defined as the temperature from which the water vapor in the air begins to condense, producing dew, fog or, if the temperature is below 0 ° C, frost. For a given mass of air, with a certain amount of water vapor (absolute humidity), the relative humidity is the proportion of vapor contained in relation to the necessary to reach the saturation point, expressed as a percentage.
Dry bulb (Tdb) temperature (chart bottom or “x” axis) is just the measured indoor temperature measured using a standard thermometer.
Relative humidity (RH) is the amount of water in the air. We use the term “relative” humidity because the amount of water that a given volume of air can hold decreases as temperatures drop. (Think of it as cold air being more dense, squeezing water molecules out of suspension in the air.) So RH is the ratio of the actual water vapor pressure in the air to the water vapor pressure in air that is fully saturated (can’t hold any more water) at that same temperature.
Wet bulb temperature (Twb) measures the amount of water that can be taken out of the air (by evaporation) – the old “sling psychrometer” used a simple mercury thermometer with a wet cloth over the sensing bulb to measure Twb by swinging the thermometer around at the end of a string – or properly: a sling psychrometer. Really.
See the left-most curve, the 100% relative humidity line for a simple case – that’s air that is 100% saturated. So on the chart above, notice that on the left-most curve, the wet bulb temperature equals the dry bulb temperature – that is, when the air is fully saturated at 100% RH, no more air water can be evaporated out of the air.
Define Dew Point: Now the good part: the dew point (Tdp) is the temperature at which water vapor just starts to condense out of air that is cooling – for example when warm moisture-laden air contacts a cool surface inside of a wall cavity. Above the dew point the moisture stays in the air. At or below the dew point moisture leaves the air and in buildings, condenses on the cooler surface that the air is contacting. This also means that if you are measuring the relative humidity in a room, the RH number only has meaning if you measure the room temperature at the same time and location.
That’s why, for example, when measuring basement humidity we will get different RH measurements in the center of the room than we will find right against a cool foundation wall.
Dew Point Example: in the chart below, if the room temperature (Tdb) is 43 degC and the relative humidity (RH) is 20% (the curved line reading up from 43 degC) then the dew point is 15 degC (reading horizontally across to the left-most curved line and noting the dew point temperature scale set along that curve).
Dew Point Example 2: in the psychrometric chart given above, read up from 50 degC dry bulb temperature to the 20% RH curve, then follow the horizontal line from that point to the left to the outermost curve on the chart.
To convert temperatures from Fahrenheit to Celsius use: Tc = (5/9)*(Tf-32) where Tc= the Celsius temperature and Tf= the Fahrenheit temperature.
The calculator uses the formula:
ΔL=L·α·ΔT
If is needed to calculate another material that is not included in the table, the calculator has a row (Other material) where the user can introduce the new linear temperature expansion coefficient (α).
The calculator provides the torque necessary in a power screw for raising or lowering a load. The collar torque friction is also calculated and it is included in the torque for raising and lowering. Self-locking and efficiency for raising are calculated. A self-locking screw will hold the load F in place without any application of torque.
Countersink for DIN 7991, DIN 7987, DIN 7988, DIN 87, DIN 88, DIN 7513, DIN 7516
DIN 75
FORM B
This Calculator provides the values of the countersink for next countersunk head screws :
DIN 87, form B
DIN 7987, form B
DIN 7991, form B
DIN 88, form B
DIN 7988, form B
DIN 7514 , form D and E from M6
DIN 7516, form B and C
Countersink for DIN 912
DIN 75
Countersink for DIN 84
DIN 75
The table shows the minimum, optimus and maximum recommended punch widht (V), radius (R) and flap (B) for bending a steel sheet. This values could be different depending on the bending machine used for bending the sheet, but we can take them as reference values.
The table shows, for differents materials, the minimum engagement depth of a threaded hole (L) to enable the screw fails before the thread of the hole.
So, it is needed to define previously, the characteristics ot the screw:
– ISO Standard Thread (available from M1 to M36)
– Property class
– Thread pitch (fine or coarse)
Finally, the table also shows, the rest of dimensions that the hole should have, according to DIN 77 norm:
– Surplus thread length
– Thread total length
– Thread runout
– Hole total length
If the result of the cell is a “-” (dash), means that the holed material resistance is lower than the screw material, and in consequence, the thread of the hole will fail before the screw.