**Conversion of units**

Clicking on an item from the content will take you to the relevant paragraph.

## Content :

**Conversion of units**

The workbook contains a table for conversion of units, material hardness
conversion and table of roughness achievable through different machining
methods.

**User interface.**

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**Download.**

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**Purchase, Price list.**

Type the value you want to convert into the input box on the left. Select
source units and target units on the right (there are two options).

The table contains comparison values for different methods for measuring
material hardness. The table also includes corresponding values of material
hardness. A description (denomination) of the measuring method is specified in
the note in the first line of the table.

The table specifies the roughness values for different methods of machining:

- In green - achievable under standard conditions.
- In yellow - achievable under special conditions.

In the graphs, the temperature curves of individual viscosity classes are
displayed. On the line [5.1] you can switch between the degrees of Celsius and
Fahrenheit. The line [5.2] is used to select curves for the viscosity index of
0,50,95.

If you need the exact viscosity for the specific temperature and the
viscosity class, select the viscosity class on the line [5.4] and enter the
temperature on the line [5.5]. There is a red cross shown in the graph, and the
exact value for the selected curve and the specific temperature is mentioned on
the line [5.6]. The line [5.7] shows the range for the selected viscosity class.

If you know the viscosity for two temperatures and you need to know the
viscosity for a different temperature, enter the temperature and viscosity
values on the lines [5.8-5.13]. The resulting viscosity is shown on the line
[5.14].

The viscosity is calculated with use of the formulas in the standard
(ASTMD341):

log(log(v + 0.7)) = A - B * log(T) ... [T...Kelvin, v...cSt,
A,B ... constants]

B = {log(log(v2 + 0.7)) - log(log(v1+0.7))} / (log(T1)-log(T2))

A = log(log(v2 + 0.7)) + B * log(T2)

v = 10^(10^(A - B * log(T))) - 0.7

The curve that is displayed in red in the graph is then defined by two points
(T1, T2, v1, v2) in the column marked as "User curve".

### 5.2 Viscosity index

The number characteristic for the viscosity dependence on the temperature.
The higher the viscosity index, the lower the viscosity dependence on the
temperature.