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ww w.flexicon.uk.comTECHNICAL DATA
Thread Data
and Cable Carrying Capacity
UNEF
Thread size
External thread
Internal thread
Pitch
imperial sizes (inches)
outside diameter (mm) inside diameter (mm) mm
American unified thread conforming to BS1580 used on circular
connectors
5
⁄
8
" -24 UNEF
5
⁄
8
"
15.9
14.7
1.06
3
⁄
4
" -20 UNEF
3
⁄
4
"
19.1
17.7
1.27
7
⁄
8
" -20 UNEF
7
⁄
8
"
22.2
20.9
1.27
1" -20 UNEF
1"
25.4
24.0
1.27
1
3
⁄
16
" -18 UNEF 1
3
⁄
16
"
30.2
28.6
1.41
1
3
⁄
8
" -18 UNEF 1
3
⁄
8
"
34.9
33.4
1.41
1
1
⁄
4
" -18 UNEF 1
1
⁄
4
"
31.8
30.2
1.41
1
7
⁄
16
" -18 UNEF 1
7
⁄
16
"
36.5
35.0
1.41
1
3
⁄
4
" -18 UNS
1
3
⁄
4
"
44.5
42.9
1.41
2" -18 UNS
2"
50.8
49.3
1.41
2
1
⁄
4
" -18 UN
2
1
⁄
4
"
57.2
55.4
1.41
Nominal
Nominal overall cross
conductor size (mm
2
)
sectional area (mm
2
) of cable
UK wiring regulations BS7671, recommend that the total cross
sectional area of the sum of the individual cables should not
exceed 40% of the cross sectional area of the conduit. The
nominal cross sectional area of single-core, stranded, PVC
insulated cables is provided as a guide only. Other cables may
have different dimensions.
1.0
6.6
1.5
7.6
2.5
9.6
4.0
14.5
6.0
18.8
10.0
29.3
16.0
40.2
25.0
63.8
35.0
83.5
50.0
113.0
70.0
149.0
95.0
204.0
M12
12.0
10.4
1.5
M16
16.0
14.4
1.5
M20
20.0
18.4
1.5
M25
25.0
23.4
1.5
M32
32.0
30.4
1.5
M40
40.0
38.4
1.5
M50
50.0
48.4
1.5
M63
63.0
61.4
1.5
M75
75.0
73.4
1.5
Thread size
External thread
Internal thread
Pitch
outside diameter (mm)
inside diameter (mm)
mm
standard thread conforming to EN60423
met r ic
Thread size
External thread
Internal thread
Pitch
outside diameter (mm)
inside diameter (mm)
mm
German standard thread conforming to DIN40430
PG7
12.5
11.3
1.27
PG9
15.2
13.9
1.41
PG11
18.6
17.3
1.41
PG13.5
20.4
19.1
1.41
PG16
22.5
21.2
1.41
PG21
28.3
26.8
1.59
PG29
37.0
35.5
1.59
PG36
47.0
45.5
1.59
PG42
54.0
52.5
1.59
PG48
59.3
57.8
1.59
PG
1
⁄
2
"
21.0
18.6
1.81
3
⁄
4
"
26.4
24.1
1.81
1"
33.3
30.3
2.31
1
1
⁄
4
"
41.9
39.0
2.31
1
1
⁄
2
"
47.8
44.8
2.31
2"
59.6
56.7
2.31
Thread size
External thread
Internal thread
Pitch
(inches)
outside diameter (mm)
inside diameter (mm)
mm
Japanese conduit thread conforming to JIS B 0202
PF/ gas
UNEF/UNS/UN
3
⁄
8
"
16.7
1.14
1
⁄
2
"
21.0
1.81
3
⁄
4
"
26.4
1.81
1"
33.3
2.21
1
1
⁄
4
"
41.9
2.21
1
1
⁄
2
"
47.8
2.21
2"
59.6
2.21
Thread size
External thread
Pitch
(inches)
outside diameter (mm)
mm
American taper pipe thread conforming to
ANS/ASME B1.20.1 - 1983
NPT
cable car rying capaci ty
Example: is LTP20 suitable for five 4.0mm
2
cables?
•
The total cross sectional area of the conductors is 5 x 14.5mm
2
= 73mm
2
•
The cross sectional area of LTP20 is 3.142 x
[
inside diameter
]
2
= 201mm
2
2
•
% of conduit cross sectional area 73 = 36%
201
This is less than 40%; therefore this conduit is suitable for this
combination of cables.
UK wiring regulations BS7671 prohibit the use of flexible or pliable
conduit as an earthing conductor.
Where conduits of 40mm and above penetrate fire barriers in
buildings the wiring regulations stipulate that internal seals should
be used to maintain fire resistance.
To meet the UK wiring regulations conduit should be self
extinguishing unless they are to be buried or contained in non
combustible material e.g: concrete or plaster.
Please telephone the Flexicon hotline for further guidance,
+44 (0)1675 466900.
UK wi r ing regulat ions