MarForm Software MarWin Lead testing and analysis

Form and lead evaluation

The following lead evaluation parameters are determined:

  • Form / position evaluation ovality / conicity / parallelism / parallel to lead evaluation
  • Form / position / lead evaluation of multiple wave numbers

Evaluation and recording

The surface structure of the sealing surface of a shaft affects the flow behavior of the fluid in question and therefore has a major influence on the sealing function. A lead structure on the sealing surface can disrupt the interaction between shaft surface, fluid and sealing lip contact surface, and the resulting feed effect can cause leakage.
Lead is a surface shape characteristic on rotationally symmetric surfaces that appears over the entire circumference.
The "Lead test" option can be used to evaluate the macro lead in accordance with Mercedes Benz standard 31007-7:

Measurement of n generated lines (72 according to MB standard MBN 31007-7)

Lead parameters

The following lead evaluation parameters are determined:

  • Number of threads DG (undulations/revolution)
  • Period length DP (mm)
  • Lead angle Dγ (degrees)
  • Lead direction
  • Lead depth Dt (µm)
  • Feed cross section per revolution DFu (µm2)
  • Percentage support surface of radial shaft seal DLu (%)

    Image output

    The measured profiles are output in the record as an image. Various image output types are available:

  • 3D cylinder, color, conventional and unfolded
  • Single generated line view as straightness profile for individual assessment of form and position parameters
  • Amplitude spectra of linear profiles as bar graph

    Or as per MBN 3100-7:

  • 3D unfolded cylinder, color
  • Surface structure of lead surface
  • View of surface profile and lead profile

    Recording measuring values

    A probe arm for T7W fitted with two stylus elements is used for recording measuring values: Element # 1 with carbide ball Ø 3 mm for mechanical centering and tilting of the workpiece on the MarForm form tester Element # 2 with diamond tip for measuring lead and form parameters


    Outside measurement on workpiece diameters 2 - 200 mm