S-BT Threaded Fastener Specification

Table Of Contents
Specifications page 63
S-BT Screw-in threaded studs
Workingloadconcept
N
S
≤N
rec
=
N
R,k
Ω
whereΩisanoverallfactorofsafety
includingallowancefor:
• errors in estimation of load
•deviationsinmaterialand
workmanship
and N
S
is,ingeneral,acharacteristic
acting load.
N
S
≈N
S,k
Workingloadconcept
Partial safety concept
N
S,d
≤N
R,d
N
S,d
=N
S,k
× γ
F
N
R,d
=
N
R,k
γ
m
whereγ
F
is a partial factor of safety
toallowforerrorsinestimationon
the acting load.
γ
m
is a partial factor of safety to
allowfordeviationsinmaterialand
workmanship.
Partial safety concept
5.2 Design concepts
TherecommendedworkingloadsN
rec
andV
rec
aregenerallysuitableforusein
typicalworkingloaddesigns.