EN

BaerCoil® thread inserts – nominal length determination

Screw strength classes
Tensile strength of the material4,65,66,66,99,810,912,914,9
< 100 N/mm²1,5 D1,5 D2,0 D2,5 D3,0 D
100 - 150 N/mm²1,5 D1,5 D2,0 D2,0 D2,5 D2,5 D2,5 D3,0 D
150 - 200 N/mm²1,0 D1,5 D1,5 D1,5 D2,0 D2,0 D2,5 D2,5 D
200 - 250 N/mm²1,0 D1,0 D1,5 D1,5 D1,5 D2,0 D2,5 D2,5 D
250 - 300 N/mm²1,0 D1,0 D1,0 D1,0 D1,5 D1,5 D2,0 D2,0 D
300 - 350 N/mm²1,0 D1,0 D1,0 D1,0 D1,5 D1,5 D1,5 D2,0 D
350 - 400 N/mm²1,0 D1,0 D1,0 D1,0 D1,0 D1,5 D1,5 D1,5 D
> 400 N/mm²1,0 D1,0 D1,0 D1,0 D1,0 D1,5 D1,5 D1,5 D

Valid at room temperature for materials (e.g. aluminum) with a ratio of (shear stress) / (tensile stress) = 0.6 to 0.7.
The calculation was based on the fact that the screw should be the weaker link in the screw connection.
Thread length: 1.5 D = 1.5 times nominal diameter
Data are without guarantee - In case of doubt, tests should be carried out.

Determination of the minimum wall thickness

d = Nominal diameter
D = Outside diameter of the holding thread
R = Residual wall thickness

R (min) = 0.375 x D
G (min) = 1.75 x D

The minimum wall thicknesses can only be determined with the aid of the respective characteristic values.
The guide formulas given refer to cast, aluminum or wrought alloys and
a length of the Baercoil thread insert of 1.5 D.