Doc. No.
TITLE:
SPECIFICATION FOR
FASTENERS AND WASHERS
FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
TABLE OF CONTENTS
0.1 Circulation List
0.2 Amendment Record
FOREWORD
1.
SCOPE
2.
REFERENCES
3.
TERMS AND DEFINITIONS
4.
REQUIREMENTS
5.
TESTS AND INSPECTION
6.
MARKING
ANNEX A – Technical Particulars
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Doc. No.
TITLE:
SPECIFICATION FOR
FASTENERS AND WASHERS
FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
0.1
Revision
No.
Date of
Issue
Page 2 of 14
Circulation List
COPY NO.
COPY HOLDER
1
Procurement Manager
2
Manager, Design
3
Manager, Construction
4
Chief Manager, Design
5
Chief Manager, Operations
0.2
Issue No.
Amendment Record
Rev No.
Date
Description of Change
(YYYY-MMDD)
Prepared by
Approved by
(Name &
Signature)
(Name &
Signature)
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Doc. No.
TITLE:
SPECIFICATION FOR
FASTENERS AND WASHERS
FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
Issue No.
Revision
No.
Date of
Issue
Page 3 of 14
FOREWORD
This specification has been prepared by the Research and Development Department
of KPLC and the Design &Operations Departments of REA. It lays down requirements
for Bolts and Nuts (complete with washers). It is intended for use by KPLC/REA in
purchasing the items.
It shall be the responsibility of the manufacturer to ensure adequacy of the design and
good engineering practice in the manufacture of the Bolts and Nuts for KPLC/REA.
The manufacturer shall submit information which confirms satisfactory service
experience with products which fall within the scope of this specification.
1.
SCOPE
1.1
This specification is for Bolts and Nuts (complete with washers) for use on overhead
power lines and associated work.
1.2
The specification covers the following:







2.
Pole Bolts
Assembly Bolts
Eye Bolts
Tie Rods (Double and Full Threaded Bolts)
Foundation Bolts
Nuts
Eye Nuts
REFERENCES
The following documents were referred to during the preparation of this specification.
In case of conflict, the provision of this specification shall take precedence.
ISO 1461:
Metallic Coatings – Hot dip galvanized coatings on fabricated ferrous
products – Requirements
KS ISO 888: Bolts, screws and studs – Nominal lengths, and thread lengths for
general purpose bolts
BS 4190:
ISO metric black hexagon bolts, screws and nuts – Specification
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Doc. No.
TITLE:
SPECIFICATION FOR
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FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
3.
Issue No.
Revision
No.
Date of
Issue
Page 4 of 14
ISO 68-1:
ISO general purpose screw threads – Basic profile – Part 1: Metric screw
threads
ISO 261:
ISO general purpose metric screw threads – General plan
ISO 10684:
Fasteners – Hot dip galvanized coatings
TERMS AND DEFINITIONS
For the purpose of this specification, the definitions given in the reference standards
shall apply.
4.
REQUIREMENTS
4.1
SERVICE CONDITIONS
The Bolts and Nuts shall be suitable for continuous use indoors and outdoors in
tropical areas in humidity of up to 90%, average ambient temperature of +30ºC with a
minimum of -1ºC and a maximum of +40ºC and saline conditions along the coast.
4.2
Pole Bolts
4.2.1. Pole bolts shall be manufactured in accordance with BS 4190 strength grade
designation 4.6.
4.2.2. Each bolt shall be supplied complete with one full nut (as per clause 4.7 of this
specification).
4.2.3. The bolts shall be ISO metric black hexagon bolts and of hot dip galvanized finish.
4.2.4. The form of thread, diameters and associated pitches shall be in accordance with ISO
261 and BS 4190 (coarse pitch). The tolerance class shall be 8g for bolts and 7H for
nuts as per BS 4190.
4.2.5. The nominal length of the bolts shall be the distance from underside of the head to the
extreme end of the shank, including any chamfer or radius. The permissible tolerance
on the nominal lengths and finish of the ends shall be in accordance with BS 4190.
4.2.6. The length of thread on pole bolts shall be as per Table 1:
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Doc. No.
TITLE:
SPECIFICATION FOR
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PART 1: BOLTS AND NUTS
Issue No.
Revision
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Page 5 of 14
Table 1: Length of threads (pole bolts)
Bolt Diameter, d
M16 (⅝’’)
M16 (⅝’’), M20 (¾’’)
M16 (⅝’’), M20 (¾’’)
M16 (⅝’’), M20 (¾’’)
M16 (⅝’’), M20 (¾’’)
M16 (⅝’’), M20 (¾’’)
M16 (⅝’’), M20 (¾’’)
M16 (⅝’’), M20 (¾’’)
Bolt Length,
mm (inch)
112 (4½’’)
175 (7’’)
225 (9’’)
275 (11’’)
300 (12’’)
325 (13’’)
350 (14’’)
400 (16’’)
Tolerance on
nominal length (mm)
±1.75
±2.0
±2.30
±2.60
±2.60
±2.85
±2.85
±3.15
Thread Length,
l, mm (inch)
38 (1½’’)
150 (6’’)
150 (6’’)
150 (6’’)
150 (6’’)
150 (6’’)
150 (6’’)
150 (6’’)
4.2.7. The diameter of the unthreaded portion of the shank of the bolts and other dimensions
shall be in accordance with Fig. 1 and Table 2.
Fig. 1: Dimensions for pole bolts and nuts
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Doc. No.
TITLE:
SPECIFICATION FOR
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PART 1: BOLTS AND NUTS
Issue No.
Revision
No.
Date of
Issue
Page 6 of 14
Table 2: Dimensions for Pole Bolts (before galvanizing)
Nominal size
and thread
diameter
M16 (⅝’’)
M20 (¾’’)
Pitch of thread
(coarse pitch
series)
2
2.5
Diameter of
unthreaded
shank
Width across
flats,
dimension ‘s’
Height of
head,
dimension ‘k’
Min.
Max.
Min.
Max.
Min.
Max.
15.30
19.16
16.70
20.84
23.16
29.16
24.00
30.00
9.55
12.10
10.45
13.90
All dimensions in mm u.o.s
4.3
Eye Bolts
4.3.1 Eye bolts shall be manufactured from steel to BS 4190 strength grade designation 4.6.
4.3.2 Eye bolts shall be of drop forged manufacture.
4.3.3 Each eye bolt shall be supplied complete with one full nut (as per clause 4.7 of this
specification).
4.3.4 Eye bolts shall be in accordance with fig. 2 and have dimensions shown in Table 3.
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Doc. No.
TITLE:
SPECIFICATION FOR
FASTENERS AND WASHERS
FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
Issue No.
Revision
No.
Date of
Issue
Page 7 of 14
Fig. 2: Eye bolt
Table 3: Dimensions for Eye Bolts
Diameter
Length of eye
bolt (dimension
A as per fig. 1)
mm (inch)
Length of
threads, mm
(inch)
M20 (¾’’)
250 (10’’)
300 (12’’)
325 (13’’)
350 (14’’)
400 (16’’)
450 (18’’)
550 (22’’)
600 (24’’)
150 (6’’)
Diameter of
unthreaded
part
Min.
Max.
19.16
20.84
Pitch of
thread
(coarse pitch
series), mm
2.5
All dimensions in mm u.o.s.
4.4
Assembly Bolts
4.4.1 Assembly bolts shall be ISO metric galvanized black hexagon bolts in accordance with
BS 4190 grade 4.6.
4.4.2 Each bolt shall be supplied complete with one full nut (as per clause 4.7 of this
specification).
4.4.3 The length of thread shall be in accordance with Table 4A.
Table 4A: Length of thread for Assembly Bolts
Bolt length, mm
(inch)
M10 & M12
38 (1½’’)
50 (2’’)
75 (3’’)
175 (7’’)
38
30
-
Bolt diameter
M16
Thread length mm
38
38
44
‘-‘ Means size not used
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M20
38
46
46
52
Doc. No.
TITLE:
SPECIFICATION FOR
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PART 1: BOLTS AND NUTS
Issue No.
Revision
No.
Date of
Issue
Page 8 of 14
4.4.4 Assembly bolts shall have other dimensions as per Table 4B.
Table 4B: Dimensions for Assembly Bolts
Nominal size
and thread
diameter
M10 (⅜’’)
M12 (½’’)
M16 (⅝’’)
M20 (¾’’)
Pitch of thread
(coarse pitch
series)
1.5
1.75
2
2.5
Diameter of
unthreaded
shank
Width across
flats
Height of
head
Min.
Max.
Min.
Max.
Min.
Max.
9.42
11.30
15.30
19.16
10.58
12.70
16.70
20.84
16.57
18.48
23.16
29.16
17.00
19.00
24.00
30.00
6.55
7.55
9.55
12.10
7.45
8.45
10.45
13.90
All dimensions in mm u.o.s
4.5
Tie Rods (Double and full threaded bolts)
4.5.1 Tie rods (double and full threaded bolts) shall be manufactured from steel to BS 4190
strength grade designation 4.6.
4.5.2 Each tie rod shall be supplied complete with four full nuts (as per clause 4.7 of this
specification).
4.5.3 Tie rods shall be in accordance with Fig. 3 and have dimensions shown in Table 5.
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TITLE:
Issue No.
SPECIFICATION FOR
FASTENERS AND WASHERS
FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
Revision
No.
Date of
Issue
Page 9 of 14
Fig. 3: Tie rod (double and full threaded bolt)
Table 5: Dimensions for Tie Rods (Double and full threaded bolts)
Nominal size
and thread
diameter
Pitch of
thread
(coarse pitch
series)
M20 (¾’’)
Double threaded bolts
(dimension as per fig 2)
A
B
C
D
Length
of bolt
Length of
thread
130
160
160
550mm
(22’’)
550mm (22’’)
190
180
180
200
200
200
(length
of bolt)
2.5
450
(18’’)
550
(22’’)
600
(24’’)
Full threaded bolts
All dimensions in mm u.o.s
4.6
Foundation Bolts
4.6.1 Foundation bolts shall be ISO metric galvanized black hexagon bolts in accordance
with BS 4190 grade 8.8.
4.6.2 Each bolt shall be supplied complete with one full nut. The nut shall be to BS 4190
strength grade 8.
4.6.3 The dimensions of foundation bolts shall be in accordance with Table 6.
Length of
bolt
450 (18’’)
500 (20’’)
550 (22’’)
Nominal
size and
thread
diameter
M22 (⅞’’)
Pitch of
thread
(coarse
pitch
series)
2.5
Diameter of
unthreaded
shank
Width across
flats
Height of
head
Min.
Max.
Min.
Max.
Min.
Max.
21.16
22.84
31.00
32.00
13.10
14.90
All dimensions in mm u.o.s
4.7
Nuts
4.7.1 These shall be full nuts to BS 4190 strength grade 4 and of hot dip galvanized finish.
4.7.2 The nuts shall be of dimensions indicated in Fig. 1 and Table 5.
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TITLE:
SPECIFICATION FOR
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PART 1: BOLTS AND NUTS
Issue No.
Revision
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Page 10 of 14
Table 5: Dimensions for Nuts (before galvanizing)
Nominal size
and thread
diameter
Pitch of thread
(coarse pitch
series)
M10 (⅜’’)
M12 (½’’)
M16 (⅝’’)
M20 (¾’’)
M22 (⅞’’)
1.5
1.75
2
2.5
2.5
Width across
flats, ‘s’
Min.
Max.
Width across
corners, ‘e’
Min.
Max.
Thickness of
Nut, ‘m’
Min.
Max.
16.57
18.48
23.16
29.16
31.00
18.72
20.88
26.17
32.95
35.03
7.55
9.55
12.45
15.45
17.45
17.00
19.00
24.00
30.00
32.00
19.60
21.90
27.70
34.60
36.90
8.45
10.45
13.55
16.55
18.55
All dimensions in mm u.o.s
4.7.3 The nuts shall be suitable for use with pole bolts, assembly bolts, eye bolts, tie rods
(double and full threaded bolts) and foundation bolts detailed in this specification.
4.8
Eye Nuts
4.8.1 Eye nuts shall be of drop forged manufacture, from steel to BS 4190 grade 4.6.
4.8.2 Eye nuts shall be in accordance with Fig. 4. The pitch of thread (coarse pitch series)
shall be 2.5mm to be compatible with M20 pole bolts and M20 eye bolts detailed in
clause 4.2 and 4.3 respectively.
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TITLE:
SPECIFICATION FOR
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PART 1: BOLTS AND NUTS
Issue No.
Revision
No.
Date of
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Page 11 of 14
Fig. 4: Eye nut
4.9
Galvanizing
4.9.1 All materials to be galvanized shall be of the full dimensions shown or specified and all
the removal of burrs shall be completed before the galvanizing process commences.
4.9.2 All galvanizing shall be done by the hot dip process (molten Zinc), not less than 98%
of which must be pure Zinc. The process shall be in accordance with ISO 1461.
4.9.3 The Zinc coating shall be uniform, clean, smooth and as free from spangle as
possible.
4.9.4 The minimum thickness of coating shall be in accordance with Table 6.
Table 6: Coating thickness
Nominal size and thread
diameter
M10 (⅜’’)
Local coating thickness
(minimum)
μm
35
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Mean coating thickness
(minimum)
μm
55
Doc. No.
TITLE:
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PART 1: BOLTS AND NUTS
Issue No.
Revision
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Date of
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Page 12 of 14
M12 (½’’)
35
55
M16 (⅝’’)
35
45
M20 (¾’’)
45
45
M22 (⅞’’)
45
45
4.10 Strength and Safe Working Load
4.10.1 All pole bolts, eye bolts, assembly bolts and tie rods shall have a safe working shear
stress of not less than 120 N/mm² ; the ultimate shear stress shall be 75% of the
ultimate tensile strength, the factor of safety being not less than 2.5.
4.10.2 Ultimate tensile strength and tensile stress for the bolts shall be as indicated in Table 7
below:
----------THIS SPACE LEFT BLANK-------
Table 7: Tensile Strength and Safe Working Load
Bolt Sizes
Ultimate
Tensile
Stress
Tensile
Stress Area
2
mm
Ultimate
Tensile
Strength
Safe
Working
Load
Safe
Working
Shear Load
kN
kN
kN
2
N/mm
M12 (½’’)
392
84.3
33.05
13.22
9.91
M16 (⅝’’)
392
157.0
61.54
24.62
18.46
M20 (¾’’)
392
245.0
96.04
38.42
28.81
4.10.3 The safe working load of eye bolt in axial direction shall be 38.42kN minimum, the
factor of safety being at least 2.5.
4.10.4 The mechanical properties and proof loads for nuts shall be in accordance with Table
8.
Table 8: Mechanical properties and proof loads for nuts
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TITLE:
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SPECIFICATION FOR
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FOR OVERHEAD LINES.
PART 1: BOLTS AND NUTS
Nominal
size of
nut
Strength grade
designation
4
8
Stress under
proof load
N/mm²
400
800
Proof load kN
Tensile
stress
area of
bolt
mm²
M10 (⅜’’)
23.2
-
58.0
M12 (½’’)
33.7
-
84.3
M16 (⅝’’)
62.8
-
157
M20 (¾’’)
98.0
-
245
M22 (⅞’’)
121.0
242.0
303
Revision
No.
Date of
Issue
Page 13 of 14
Brinell
Hardness
(HB)
max
(all nuts)
Rockwell
Hardness
(HRC)
max
(all nuts)
Vickers
Hardness
(HV)
max
(all nuts)
Grade
4
Grade
8
Grade
4
Grade
8
Grade
4
Grade
8
302
302
30
30
310
310
5 TESTS AND INSPECTION
5.1
Bolts and Nuts shall be tested and inspected in accordance with BS 4190, ISO 1461,
ISO 10684 and this specification. It shall be the responsibility of the manufacturer to
perform or to have performed all the relevant tests.
5.2
Certified true copies of previous test reports by the relevant International or National
Testing/Standards Authority of the country of manufacture (or ISO/IEC 17025
accredited laboratory) shall be submitted with the offer for evaluation (all in English
Language). A copy of accreditation certificate for the laboratory shall also be
submitted.
Copies of test reports to be submitted shall include tensile strength, proof load,
verification of dimensions and galvanizing tests.
5.3
Routine and sample test reports for the bolts and nuts to be supplied shall be
submitted to KPLC/REA for approval before shipment/delivery of the goods.
5.4
On receipt of the goods KPLC/REA may perform any of the relevant tests in order to
verify compliance with this specification. The supplier shall replace without charge to
KPLC/REA bolts and nuts which upon examination, test or use fail to meet any of the
requirements in the specification.
…………………………………………………………………………………………………………….
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TITLE:
SPECIFICATION FOR
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PART 1: BOLTS AND NUTS
ANNEX A:
Issue No.
Revision
No.
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Page 14 of 14
Technical Particulars (to be filled and signed by the Manufacturer for all
clauses and submitted together with catalogues, brochures, drawings,
technical data and test reports for tender evaluation)
Clause Number Bidder’s offer
Reference
page
on
Manufacturer’s
catalogue,
drawing, technical data or tests
report to support the offer.
NB: - This schedule does not in any way substitute for detailed information required elsewhere in the
specification.
…………………………………………………………………………………….
Manufacturer’s Name, Signature, Stamp and Date
Issued by:
Authorized by:
Signed:
Signed:
Date:
Date: