S-BT Threaded Fastener Specification
Table Of Contents
- 1.1 Definition
- 1.2 The S-BT system
- 1.3 Fastening mechanism
- 1.4 S-BT system features and benefits – simplified fastening to steel
- 2.1 Grating fastening system
- 2.2 Grating fastening system X-FCS-R
- 2.3 S-BT with MM and MQ installation channel system
- 2.4 Fastening instrumentation, junction boxes and lighting
- 2.5 Fastening cable / conduit connectors
- 2.5 Fastening cable tray supports
- 2.7 Electrical connections
- 3.1 Product data
- 3.2 Load data
- 4.1 Instruction for use - S-BT-MF M6, M8, M10, W6, W10
- 4.2 Instruction for use - S-BT-MF M8/7 AN 6
- 4.3 Instruction for use - S-BT-MR M6, M8, M10, W6, W10 SN 6
- 4.4 Instruction for use - S-BT-MR M8/7 SN 6
- 4.5 Instruction for use - S-BT-MR M6, M8, M10, W6, W10 SN 6 AL
- 4.6 Instruction for use - S-BT-MR M8/7 SN 6 AL
- 4.7 Instruction for use - S-BT-GF M8/7 AN 6
- 4.8 Instruction for use - S-BT-GR M8/7 SN 6
- 4.9 Instruction for use - S-BT-GR M8/7 SN 6 AL
- 4.10 Instruction for use – S-BT-EF M6/W6/M8
- 4.11 Instruction for use – S-BT-EF M10/W10
- 4.12 Instruction for use – S-BT-ER M6/W6/M8
- 4.13 Instruction for use – S-BT-ER M10/W10
- 4.14 Instruction for use – S-BT-EF W10 HC AWG2/0 and S-BT-EF M10 HC 35/120
- 4.15 Instruction for use – S-BT-ER W10 HC AWG2/0 and S-BT-ER M10 HC 35/120
- 5.1 Nomenclature and symbols
- 5.2 Design concepts
- 5.3 Static capacity of the S-BT threaded stud
- 5.4 Vibration effects on S-BT threaded stud fastenings
- 5.5 Resistance of S-BT fastenings under dynamic tensile loading
- 5.6 Effect of S-BT threaded stud fastenings on the fatigue strength of base material structural steel
- 5.7 Influence of glue coatings on the loosening torque
- 5.8 S-BT-ER and S-BT-EF screw-in threaded studs for electrical connections
- 5.9.5 Conductivity disc of S-BT-ER / -EF electrical connectors
- 5.9.4 Stainless steel S-BT studs
- 5.9.3 Carbon steel S-BT studs
- 5.9.2 Galvanic (contact) corrosion
Specifications page 77
S-BT Screw-in threaded studs
Universität Stuttgart
Institut für Konstruktion und Entwurf
Schwerpunkte: Stahlbau, Holzbau und Verbundbau
Prof. Dr.-Ing. Ulrike Kuhlmann
2017-06-30 S-BT Fatigue Page 38
9.2.5 Recommendation of a design S-N curve for DNVGL-RP-C203:2016
DNVGL-RP-C203:2016 (Offshore) includes 14 basic design S-N curves for direct stress in air
environment. The slope intersection is again at 1
∙10
7
number of cycles. In general the slope
varies between m = 3 to 4 as typical for welded details. The 14 S-N curves in DNVGL-RP-
C203:2016 are in principle similar to those given in EN 1993-1-9:2005 and the IIW-
Recommendations. For example the S-N curve C2 corresponds with detail class 100 with
m
1
= 3 in EN 1993-1-9 and the IIW-Recommendations.
Based on the statistical evaluation of S-BT fatigue test data according to
Table 9.1 an additional
curve is proposed having a uniform slope of m = 5, see following
Table 9.5 and Figure 34. Ac-
cording to the standard S-N curves given in DNVGL-RP-C203:2016 the slope is set to be con-
stant to m = 5 beyond N = 1
∙10
7
cycles.
Table 9.5. Basic design S-N curves in air, see Table 2-1 of DNVGL-RP-C203
S-N curve
N
10
7
cycles
N > 10
7
cycles
log a
2
m
2
= 5.0
Fatigue limit
at 10
7
cycles
[MPa]
Tickness
exponent k
m
1
log a
1
B1
4.0 15.117 17.146 106.97 0
B2
4.0 14.885 16.858 93.59 0
C
3.0 12.592 16.320 73.10 0.05
C1
3.0 12.449 16.081 65.50 0.10
C2
3.0 12.301 15.835 58.48 0.15
D
3.0 12.164 15.606 52.63 0.20
E
3.0 12.010 15.350 46.78 0.20
F
3.0 11.855 15.091 41.52 0.25
F1
3.0 11.699 14.832 36.84 0.25
F3
3.0 11.546 14.576 32.75 0.25
S-BT 5.0 16.300 16.300 72.4 0
10
100
10000 100000 1000000 10000000
Number of cycles N [-]
Nominal stress range [N/mm
2
]
300
200
100
400
50
500
B1
10
70
20
t
Hilti S-BT
C
C1
E
D
DNVGL
S-N
curves
w
elded stud
B2
C2
Hilti S-BT fastener
(correctly installed)
Hilti S-BT fastener
(installed and removed)
proposed design S-N curve
m =5
1
F
Figure 34. Comparison of Hilti S-BT fatigue test data with DNVGL-RP-C203:2016 fatigue curves
and new proposed fatigue curve for Hilti S-BT fastener
Universität Stuttgart
Institut für Konstruktion und Entwurf
Schwerpunkte: Stahlbau, Holzbau und Verbundbau
Prof. Dr.-Ing. Ulrike Kuhlmann
2017-06-30 S-BT Fatigue Page 45
10.2.5 BV:2016
It is recommended to use the following S-N curve respectively stress category termed “S-BT”
given in
Table 10.4 for the constructional detail “Steel base material with Hilti S-BT screw-in
threaded studs”.
Table 10.4. Recommendation of fatigue design S-N curve and stress category according to BV:2016, air
Joint and detail description Curve Geometry Requirements
Hilti S-BT screw-in stainless and carbon
steel threaded studs with pre-drilled hole
in structural steel base material.
Imperfect fastener installations as e.g.
overwound or pulled-out fasteners are
covered.
Potential crack initiation at the edge or
tip of the pre-drilled hole.
S-BT
to be calculated by the gross
cross-section.
Installation, static loading and
spacing of fasteners only in ac-
cordance with the requirements
given in [1] or [2].
Plate thickness t 3 mm.
Steel base material up to yield
strength 355 MPa.
Parameter of design S-N curve S-BT
Curve FAT First slope Slope intersection Second slope Thickness
S [MPa]
m
1
log
10
(K
1
) N
cycles
S
q
[MPa]
m
2
log
10
(K
2
) exponent n
S-BT 100 5.0 16.300 10
7
72.40 5.0 16.300 0
[1] Hilti S-BT screw-in threaded studs. Specification Binder, Edition 01/2017
[2] Hilti Direct Fastening Technology Manual. Edition 12/2016. S-BT product pages.
10.2.6 DNVGL-RP-C203:2016
It is recommended to use the following S-N curve respectively stress category termed “S-BT”
given in
Table 10.5 for the constructional detail “Steel base material with Hilti S-BT screw-in
threaded studs”.
Table 10.5. Recommendation of fatigue S-N curve and detail category according to DNVGL-RP-C03, air
Detail
category
Construction detail Description Requirements
S-BT
Hilti S-BT screw-in stainless
and carbon steel threaded
studs with pre-drilled hole in
structural steel base material.
Imperfect fastener installa-
tions as e.g. overwound or
pulled-out fasteners are cov-
ered.
to be calculated by the gross
cross-section.
Installation, static loading and spac-
ing of fasteners only in accordance
with the requirements given in [1] or
[2].
Plate thickness t 3 mm.
Steel base material up to yield
strength 355 MPa.
Parameter of S-N curve for detail category S-BT
Detail
category
N
10
7
cycles
N > 10
7
cycles log a
2
m
2
= 5.0
Fatigue limit at 10
7
cycles [MPa]
Thickness exponent
k
m
1
log a
1
S-BT 5.0 16.300 16.300 72.4 0
[1] Hilti S-BT screw-in threaded studs. Specification Binder, Edition 01/2017
[2] Hilti Direct Fastening Technology Manual. Edition 12/2016. S-BT product pages.
DNVGL-RP-C203:2016
ItisrecommendedtousethefollowingdesignS-Ncurverespectivelystress
categorytermed“S-BT”giveninTable7andFigure5fortheconstructional
detail“SteelbasematerialwithHiltiS-BTscrew-inthreadedstuds”.
Universität Stuttgart
Institut für Konstruktion und Entwurf
Schwerpunkte: Stahlbau, Holzbau und Verbundbau
Prof. Dr.-Ing. Ulrike Kuhlmann
2017-06-30 S-BT Fatigue Page 38
9.2.5 Recommendation of a design S-N curve for DNVGL-RP-C203:2016
DNVGL-RP-C203:2016 (Offshore) includes 14 basic design S-N curves for direct stress in air
environment. The slope intersection is again at 1
∙10
7
number of cycles. In general the slope
varies between m = 3 to 4 as typical for welded details. The 14 S-N curves in DNVGL-RP-
C203:2016 are in principle similar to those given in EN 1993-1-9:2005 and the IIW-
Recommendations. For example the S-N curve C2 corresponds with detail class 100 with
m
1
= 3 in EN 1993-1-9 and the IIW-Recommendations.
Based on the statistical evaluation of S-BT fatigue test data according to
Table 9.1 an additional
curve is proposed having a uniform slope of m = 5, see following
Table 9.5 and Figure 34. Ac-
cording to the standard S-N curves given in DNVGL-RP-C203:2016 the slope is set to be con-
stant to m = 5 beyond N = 1
∙10
7
cycles.
Table 9.5. Basic design S-N curves in air, see Table 2-1 of DNVGL-RP-C203
S-N curve
N 10
7
cycles
N > 10
7
cycles
log a
2
m
2
= 5.0
Fatigue limit
at 10
7
cycles
[MPa]
Tickness
exponent k
m
1
log a
1
B1
4.0 15.117 17.146 106.97 0
B2
4.0 14.885 16.858 93.59 0
C
3.0 12.592 16.320 73.10 0.05
C1
3.0 12.449 16.081 65.50 0.10
C2
3.0 12.301 15.835 58.48 0.15
D
3.0 12.164 15.606 52.63 0.20
E
3.0 12.010 15.350 46.78 0.20
F
3.0 11.855 15.091 41.52 0.25
F1
3.0 11.699 14.832 36.84 0.25
F3
3.0 11.546 14.576 32.75 0.25
S-BT 5.0 16.300 16.300 72.4 0
10
100
10000 100000 1000000 10000000
Number of cycles N [-]
Nominal stress range [N/mm
2
]
300
200
100
400
50
500
B1
10
70
20
t
Hilti S-BT
C
C1
E
D
DNVGL
S-N
curves
w
elded stud
B2
C2
Hilti S-BT fastener
(correctly installed)
Hilti S-BT fastener
(installed and removed)
proposed design S-N curve
m =5
1
F
Figure 34. Comparison of Hilti S-BT fatigue test data with DNVGL-RP-C203:2016 fatigue curves
and new proposed fatigue curve for Hilti S-BT fastener
Figure5:ComparisonofHiltiS-BTfatiguetestdatawithDNVGL-RP-C203:2016
fatiguecurvesandnewproposedfatiguecurve“S-BT”forHiltiS-BTfastener
Table7:RecommendationoffatigueS-Ncurveanddetailcategoryacc.to
DNVGL-RP-C203,air