SHS Jointing, Flowdrill & Hollo-Bolt - Tata Steel

Drilling machine parameters :
Table 1 gives a guide to required machine
parameters for producing Flowdrill holes for
M12 to M24 bolts:
Note: The Flowdrill process is not suitable for
hand held or magnetic clamp type drilling
equipment when used in the sizes shown.
Max material
thickness
(mm)
Flowdrill detailing requirements.
See Fig. 3 and Table 3.
Note:
3
5
6
8
10
12
16
Table 2
● Flowdrilled joints used at
locations exposed to the
weather should not be
considered as water tight.
● Flowdrilling is not suitable
for use with pre-galvanised
materials.
Dimensions
(mm)
A 1
B 1
C 1
D 1
E 1 Minimum
Min Bolt Centres
M12
Short
Long
Long
Long
-
-
-
Flowdrill Length
M16
Short
Short
Long
Long
Long
-
-
Thread Size
M12
7
13
18
30
M20
Short
Short
Short
Long
Long
Long
-
Lb
tp
M24
Short
Short
Short
Long
Long
Long
-
tc
M16
10
17
20
40
Thread size
Flowdrill size
M/c spindle
speed rpm
M/c feed rate
Motor power
KW Min
Tapping speed
rpm
Table 3 (See Fig. 3 for nomenclature)
M12
10.9
1000-1500
2
250
M16
14.8
700-1100
Table 1
Drill length: The recommended length of
Flowdrill bits varies with the thread size and
thickness of material as given in Table 2.
Drill care: Flowdrills are made from tungsten
carbide. They are extremely hard but cannot
withstand shock loads. After drilling each hole,
FD KS paste should be applied to the Flowdrill
whilst it is still hot, so minimising oxidation and
preventing ‘build up’ on the surface.
Flat surface: the raised rim on the outer surface
of the RHS material caused during Flowdrilling
should be removed using Flowdrills with cutting
edges provided on the collar. One rotation of the
cutter is all that is required to remove the rim.
B 1
C 1
Width
Min bolt centres
Thread size/Bolt diameter
2.5
200
M20
18.7
600-1000
3.5
150
M24
22.5
500-800
0.1/0.15mm (0.004/0.006 inches) per rev
M20
12
22
26
Varies with overall bolt length (Lb) specified
C 1/2 + t c (for connection made to a single face or opposite faces)
B 1/2 + A 1 + D 1 + t c (for connection made to adlacent faces)
A 1
D 1
50
E 1
M24
15
25
29
60
5
100
Fig. 3
E 1