Hexagonal bolt with flange in accordance with MBN standard

Surface protection:

In accordance with DBL 1740.40 (silver-coloured Cr(VI)-free) → VDA 235-104.42

Corrosion resistance:

• ≤ M8 → approx. 480 h with no base metal corrosion in accordance with DIN EN ISO 9227-NSS.


• ≥ M10 → approx. 720 h with no base metal corrosion in accordance with DIN EN ISO 9227-NSS.

The specified corrosion resistances apply for corrosion tests in accordance with DIN EN ISO 9227-NSS (salt spray tests), at the earliest 24 h after coating, in the "as coated" state, i.e. before sorting, packaging, transporting and/or assembly. Inevitable handling and assembly processes may reduce these values. Applying the corrosion resistance values resulting from the salt spray test to real assembly and operating conditions is not possible in the majority of cases. When designing a connection, both the combined materials - and, if necessary, coatings - as well as the environmental conditions during operation must be considered by the designer in the selection of a suitable corrosion protection coating.

Friction coefficient:

μ_tot = 0.09-0.14 (VDA 235-101)

Flange head screws reduce the risk of pretensioning force loss when placed on the contact surfaces. The surface pressure generated under the screw head during tightening is low compared to conventional hexagon heads (without flange), as the force is distributed over a larger contact surface.

Advantage:

• Less setting required due to fewer parts to be connected compared to connections using washers.


• The concave washer pressing against the contact surface increases the elasticity of the connection so that the setting/creeping movements that occur are counteracted and pretensioning force loss is generally prevented.

MBN 10105 has been replaced by MBN 50105.