Installation Typicals - Fastening on Steel Threaded Studs

Application
• Fastening of junction boxes, switches on a vertical structure
• Element is fastened by X-BT-MR
Boundary conditions
• These values are ONLY reflecting capacity of X-BT-MR 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 X-BT-MR (06 / 2018),
always refer to latest technical data binder for X-BT-MR
Conditions for recommended loads
• Global factor of safety for static pull-out > 3 (based on 5% fractile value),
≥ 5 (based on mean value)
• Minimum edge distance = 6 mm [¼"]
• Effect of base metal vibration and stress considered
• Redundancy (multiple fastening) must be provided
• Recommended loads in the table refer to the resistance of the individual
fastening and may not be the same as the loads F
N
and F
V
acting on the
fastened part
Note: if relevant, prying forces need to be considered in design, see example.
Moment acting on fastener shank only in case of a gap between base and
fastened material.
Design resistance X-BT-MR
Drill hole type and base material thickness Pilot hole, t
II
≥ 8 mm (0.31")
Base material
Steel S235 A36 Steel S355 Grade 50 Cast iron with spheroidal graphite
Tension, N
Rd
[kN / lb]
5.0 6.5 1.6
Shear, V
Rd
[kN / lb]
6.0 7.5 2.4
Moment, M
Rd
[Nm / ft-lb]
28.0 28.0 26.0
Recommended load X-BT-MR
Drill hole type and base material thickness Pilot hole, t
II
≥ 8 mm (0.31")
Base material
Steel S235 A36 Steel S355 Grade 50 Cast iron with spheroidal graphite
Tension, N
rec
[kN / lb]
3.6 / 810 4.6 / 1030 1.0 / 230
Shear, V
rec
[kN / lb]
4.3 / 970 5.3 / 1190 1.5 / 340
Moment, M
rec
[Nm / ft-lb]
20.0 / 14.8 20.0 / 14.8 16.0 / 11.5
Technical data — always refer to latest technical data binder for X-BT-MR
FASTENING JUNCTION BOXES / SWITCHES
WITH X-BT-MR*
X-BT-MR Threaded stud
X-BT-MR • Metric
*X-BT-MR is the new generation X-BT
V
V
rec
N
N
rec
M
M
rec
+ + 1.0≤
V–N–M (shear, tension
and bending)
N
N
rec
M
M
rec
+ 1.0≤
N–M (tension
and bending)
V
V
rec
V
V
rec
M
M
rec
M
M
rec
+
with and
1.2
1.0 1.0
≤
≤ ≤
V–M (shear
and bending)
V
V
rec
V
V
rec
N
N
rec
N
N
rec
+
with and
1.2
1.0 1.0
≤
≤ ≤
V–N (shear
and tension)
Recommended interaction formula for combined loading — steel and cast
iron base material
Combined
loading situation Interaction formula
24Issued August 2018, expiry January 2022