Installation Typicals - Fastening on Steel Threaded Studs

FASTENING JUNCTION BOXES / SWITCHES
WITH S-BT
S-BT-MR / S-BT-MF Threaded stud
Conditions for recommended loads
• Use S-BT-MR and S-BT-MF (multi-purpose fastening) only with the supplied
Hilti serrated flange nuts M8, M10 and W10 ( or  as per according to
General Information — Material specifications
• Global factor of safety Ω for static pull-out and static shear ≥ 3 (based on
mean ultimate test value)
• Minimum edge distance = 6 mm [0.24"], minimum spacing = 15 mm [0.59"]
• Effect of base metal vibration and stress (e.g. areas with tensile
stress) considered
• Redundancy (multiple fastening) must be provided
• If eccentric loading exists (e.g. use of an angle clip), moments caused by
off-center loading must be considered
Technical data — always refer to latest technical data binder for S-BT
S-BT-MR / S-BT-MF • Imperial
Recommended interaction formula for combined loading — steel and
aluminum base material
Cyclic loading
S-BT threaded studs are only to be used for fastenings subject to static or quasi-static
loading. Inquire at Hilti for test data if cyclic loading has to be considered in the design.
N–M (tension
and bending)
N
N
rec
M
M
rec
+ 1.0≤
V–N–M (shear, tension
and bending)
V
V
rec
N
N
rec
M
M
rec
+ + 1.0≤
V–N (shear
and tension)
V
V
rec
V
V
rec
N
N
rec
N
N
rec
+
with and
1.2
1.0 1.0
≤
≤ ≤
V–M (shear
and bending)
V
V
rec
V
V
rec
M
M
rec
M
M
rec
+
with and
1.2
1.0 1.0
≤
≤ ≤
Design resistance S-BT S-BT
Drill hole type and base
material thickness
Pilot hole, t
II
≥ 6 mm (0.24")
Drill through hole, 5 mm (0.20") ≤ t
II
< 6 mm (0.24")
Drill through hole,
3 mm (0.12") ≤ t
II
< 5 mm (0.20")
Pilot hole,
5 mm (0.20") ≤ t
II
< 6 mm (0.24")
Base material
Steel S235
A36
Steel S355
Grade 50
Aluminum
f
u
≥ 270 mPa
Steel S235
A36
Steel S355
Grade 50
Steel S235
A36
Steel S355
Grade 50
Tension, N
Rd
[kN / lb]
2.5 / 560 3.2 / 720 1.4 / 315 1.4 / 315 1.8 / 405 1.4 / 315 1.8 / 405
Shear, V
Rd
[kN / lb]
3.6 / 810 4.5 / 1010 2.1 / 470 2.1 / 470 2.7 / 610 2.1 / 470 2.7 / 610
Moment, M
Rd
[Nm / ft-lb]
9.8 / 7.2 9.8 / 7.2 6.7 / 4.9 9.8 / 7.2 9.8 / 7.2 8.7 / 6.4 8.7 / 6.4
Recommended load S-BT S-BT
Drill hole type and base
material thickness
Pilot hole, t
II
≥ 6 mm (0.24")
Drill through hole, 5 mm (0.20") ≤ t
II
< 6 mm (0.24")
Drill through hole,
3 mm (0.12") ≤ t
II
< 5 mm (0.20")
Pilot hole,
5 mm (0.20") ≤ t
II
< 6 mm (0.24")
Base material
Steel S235
A36
Steel S355
Grade 50
Aluminum
f
u
≥ 270 mPa
Steel S235
A36
Steel S355
Grade 50
Steel S235
A36
Steel S355
Grade 50
Tension, N
rec
[kN / lb]
1.8 / 405 2.3 / 520 1.0 / 225 1.0 / 225 1.3 / 290 1.0 / 225 1.3 / 290
Shear, V
rec
[kN / lb]
2.6 / 585 3.2 / 720 1.5 / 340 1.5 / 340 1.9 / 430 1.5 / 340 1.9 / 430
Moment, M
rec
[Nm / ft-lb]
7.0 / 5.2 7.0 / 5.2 4.8 / 3.5 4.8 / 3.5 7.0 / 5.2 6.2 / 4.6 6.2 / 4.6
Application
• Fastening of junction boxes, switches on a vertical structure
• Element is fastened by S-BT
Boundary conditions
• These values are ONLY reflecting capacity of S-BT threaded stud. Structural
analysis of support / structure is NOT in Hilti scope. See the detailed
statements in disclaimer — 2018/05/04
• Technical data are based on technical data binder for S-BT (06 / 2018),
always refer to latest technical data binder for S-BT
94Issued August 2018, expiry January 2022