Help is a software calculator that helps you to design and verify machine elements according standard. These calculations are often tedious, error-prone and in sum very time-consuming. The online calculator offers remedy: With mechanicalcheck all converting calculations can be done quickly, properly and well documentated.

General information about the user interface

Please fill in all input boxes. Output boxes in grey ('output') are only for information and are locked.

Results are displayed after all necessary data has been entered. Otherwise the output-fields display 'output'.

Data from a selection list is sent immediately to the system and the page will be updated. Data from selection lists are linked with each other, possible selections from lists will be updated as well. Thus only possible combinations can be selected. If you wish to reset your selection, please select '-' from the selection list. If you wish to reset all lists, you can reset the whole page by clicking 'calc' in the title-section.


The data base of the online calculator includes the materials listed in DIN 6892

DIN EN 10025 (Structural steel),
DIN EN 10277-5 (Bright steel),
DIN EN 10083-1 (Quenched and tempered steel),
DIN EN 10083-2 (Quenched and tempered steel),

and additionally

DIN EN 10083-3 (Quenched and tempered steel),
DIN EN 10277-2 (Bright steel) and
DIN EN 10277-3 (Bright steel).

For materials according DIN EN 10084 (Case hardened steels, previously DIN 17210) no generally accepted data has been found.

Mechanical properties

Because for many materials the mechanical properties are influenced by the mechanical or heat treatment, information about the treatment is added:

+C (cold drawn),
+N (normalized),
+QT, +QT1 oder +QT2 (quenched, tempered),
+QT+C, (quenched, tempered and cold drawn),
+C+QT, (cold drawn and quenched, tempered)

The field 'Shaft'

Please fill in data for shaft here. From the diameter and material name the online calculator calculates the allowable strength limit for the shaft. Furthermore the choice of the appropriate parallel key and the allowable torque is influenced by the diameter.

The Field 'Parallel Key'

Please fill in data for the parallel key here.

Standard: You can select parallel keys according standard DIN 6885-1 or DIN 6885-3. It is possible to select standard 6885-3, though it is quite unusual. If you are not sure just select 6885-1 (this is also the default value).

Shape: You can select shape A, B, C, D, E, F, G, H, or J. Please consider that keys according DIN 6883-3 exist only with shapes A, B, C, E. If you are not sure just select A (this is also the default value).

Length: Please enter the length (overall) of the key. The ratio between length and diameter (l_PF/d) should not increase the value of 1.3.

Material: According standard 6885-1 the following materials are suggested

E295GC +C für h < 25 mm
E335GC +C für 25 < h < 50 mm

or according standard 6885-3:

E335GC +C für h < 12 mm.

Nevertheless it is quite usual to select also other materials. If you are not sure, just select C45 +C (this is also the default value), because this material is very popular for keys.

The field 'Hub'

Please enter the data for hub here.