MAN M 3150-1 Surface Quality - Cabin Body

The “MAN M 3150-1 Surface quality - Cabin body” standard, developed by the MAN automotive company, describes the requirements for the cabin body within the scope of surface quality of vehicles.

Essentially, the MAN M 3150 series of standards is designed to allow uniform assessment of the surface quality and structure and colour matching of coatings on MAN commercial vehicles (cab, cabin add-on parts, chassis, bus exterior cladding and bus interior) and is valid for both in-house and purchased parts.

The MAN M 3150-1 standard applies to trucks. It allows for a standardised assessment of the interior and exterior surface quality of the cab body, regardless of the quality and type of component material (sheet metal, plastic, etc.).

The purpose of this part of the M 3150 series of standards is to specify uniform criteria for the evaluation of the surface quality of the car body in order to guarantee a uniform surface condition for the final coating. The requirements are derived from customer requirements and state-of-the-art technology.

The required surface quality of the car body is a minimum requirement. Unless otherwise specified on the component drawing, surface quality is carried out in accordance with the evaluation zones defined in this standard. Exceptions are only permitted through valid initial samples or limit samples.

The evaluation zones are generally explained in the table provided in the standard as follows:

• Zone 1 (yellow) (formerly Zone A, red): Includes all surfaces where irregularities are particularly disturbing and immediately noticeable.
• Zone 2 (blue) (previous Zone B, yellow): Includes all surfaces where irregularities are not immediately noticeable.
• Zone 3 (green) (formerly Zone C, green): Contains all hidden surfaces that are rarely or briefly visible while the vehicle is in use.

The requirements for assessment zones are defined as follows:

• Possible types of defects and their allowable tolerances are defined in the table provided in the standard, depending on where they occur.
• The following criteria should be taken into account for defect assessment:
  • Display location and method: Object in installation position.
  • Viewing distance: At least 0,5 m.
  • Lighting conditions: The lighting technology is defined by standard DIN EN 12464-1. A guide value of 1000 lx is specified for final examination.
• The evaluation zones are shown in the detailed drawings in the standard. The transfer of the evaluation zones to all other model ranges should be done in a similar way to the drawings.

In this standard, defect types and evaluation methods are explained in a table on the following basis:

• Roughness
• Marking, labeling is not complete
• No burrs, no ground, no smoothing
• Cutting burr, contour
• Cutting burr
• Unexposed / border position missing
• Scratch marks, scratch grooves
• Inequality, traces of collapse
• Depressions, protrusions
• Grinding defects
• Pressure marks, scratches
• Slip line
• Slimming
• Visible pimples without sanding
• Adhesive residue
• Glue marks
• Unaligned/not adapted, offset, not aligned
• Gap size is not ok
• Wrong, not in accordance with assembly instructions / drawing
• Torn, torn / broken
• Material defect
• Spot source is not complete
• Burrs in spot welds
• The binding is not complete
• Roll stitching or projection welding or laser stitching is not ok
• Inert gas welding or brazing is not ok
• Oily, contaminated with oil
• Damaged

Among the numerous tests, measurements, analyses and evaluation studies carried out for businesses in various sectors, our organization also provides testing services defined in the “MAN M 3150-1 Surface quality - Cabin body” standard with its trained and expert staff and advanced technological equipment.