Special screws Guldner GmbH & Co. KG

Stainless steel|Expansion screws|for Industrial use

Screw connections with expansion shank (eg DIN 2510) are particularly suitable for constructions that are subject to changing operating forces and changing temperatures and if a durability of the screw connection is to be ensured. The favorable behavior of Dehnschraubenverbindungen based on their elasticity, and in particular the fact that they have a greater elastic change in length with the same bias as so-called rigid screw connections. This behavior has a number of advantages:

• Expansion screws show a good durability, because the additional stresses of the screws themselves by changing operating forces and temperature expansions and bending moments are reduced.

• The preload drop, which contributes significantly to the loosening of the screw connections - during operation by creep of the material, settling in the force-transmitting surfaces of the connection and the strained parts, as well as by bending the threads - is lower.

• The height of the applied preload can be measured under certain conditions in a simple manner by changing the length of the screw.

• When designing expansion bolts and expansion bolts, the following points should be noted:

• The minimum extension shaft length should be twice or better four times the thread diameter to obtain sufficient elasticity.

• The ratio of the thread core diameter to the shank diameter should be about 1.1 in terms of the load capacity and elasticity of the screw.

• The transition angle between the expansion shaft and the thread should be relatively small. This results in a favorable flow of force and a better load distribution in the screwed thread.