Specification for Holding down bolts docx

BRITISH STANDARD
BS 7419:1991
Specification for
Holding down bolts
BS7419:1991
This British Standard, having
been prepared under the
directionof the General
Mechanical Engineering
Standards Policy Committee,
waspublished under the
authorityof the Standards
Boardand comes
into effect on
29March1991
© BSI 12-1999
The following BSI references
relate to the work on this
standard:
Committee reference GME/9
Draft for comment 90/75944 DC
ISBN 0 580 19403 5
Committees responsible for this
BritishStandard
The preparation of this British Standard was entrusted by the General
Mechanical Engineering Standards Policy Committee (GME/-) to Technical
Committee GME/9, upon which the following bodies were represented:
BEAMA Ltd
British Constructional Steelwork Association Ltd
British Industrial Fasteners Federation
British Railways Board

British Steel Industry
British Steel Industry (Wire Section)
Gauge and Tool Makers’ Association
Ministry of Defence
Society of Motor Manufacturers and Traders Limited
Washer Manufacturers’ Association of Great Britain
The following body was also represented in the drafting of the standard,
through subcommittees and panels:
Steel Construction Institute
Amendments issued since publication
Amd. No. Date Comments
BS7419:1991
© BSI 12-1999
i
Contents
Page
Committees responsible Inside front cover
Foreword ii
1 Scope 1
2 Dimensions 1
3 Characteristics 6
4 Complete designation for the purpose of an enquiry or order 6
Figure 1 — Dimensions of square head bolts 3
Figure 2 — Dimensions of hexagon head bolts 5
Table 1 — Dimensions of square head bolts 2
Table 2 — Dimensions of hexagon head bolts 4
Table 3 — Tolerance on nominal length 6
Table 4 — Preferred sizes 6
Table 5 — Characteristics 6
Publication(s) referred to Inside back cover

BS7419:1991
ii
© BSI 12-1999
Foreword
This British Standard has been prepared under the authority of the General
Mechanical Engineering Standards Policy Committee to provide a metric series
standard for holding down bolts.
A British Standard does not purport to include all the necessary provisions of a
contract. Users of British Standards are responsible for their correct application.
Compliance with a British Standard does not of itself confer immunity
from legal obligations.
Summary of pages
This document comprises a front cover, an inside front cover, pagesi andii,
pages1 to6, an inside back cover and a back cover.
This standard has been updated (see copyright date) and may have had
amendments incorporated. This will be indicated in the amendment table on the
inside front cover.
BS7419:1991
© BSI 12-1999
1
1 Scope
This British Standard specifies the general
dimensions, tolerances, materials and mechanical
properties for holding down bolts of product grade C
for use in connecting steel structures to their
foundations and in similar applications.
Bolts with square heads and square necks are
specified. Two possible forms of square neck are
covered.
Bolts with hexagon heads are also specified.

Other forms of holding down bolts are not covered.
NOTEThe titles of the publications referred to in this standard
are listed on the inside back cover.
2 Dimensions
The general dimensions and tolerances of holding
down bolts with square heads and square necks
shall be as given inTable 1 andTable 3, and
Figure 1.
The dimensions and tolerances of holding down
bolts with hexagon heads shall be as given in
Table 2andTable 3,andFigure 2.
NOTE 1Preferred sizes for square and hexagon head holding
down bolts are listed inTable 4.
NOTE 2Symbols and descriptions of dimensions may be found
in BS 6565. The symbol v is the dimension across flats of the
underhead square neck.
BS 7419
:
1991
2
© BSI 12-1999
Table 1 — Dimensions of square head bolts
Thread (d) M16 M20 M24 M30 M36 M42 M48 M56 M64
P (pitch)
2 2.5 3 3.5 4 4.5 5 5.5 6
b max. 122 127.5 133 140.5 148 155.5 163 172.5 182
min. 116 120 124 130 136 142 148 156 164
d
s
max. 16.7 20.84 24.84 30.84 37 43 49 57.2 65.2

min. 15.3 19.16 23.16 29.16 35 41 47 54.8 62.8
k nom. 10 12.5 15 18.7 22.5 26 30 35 40
min. 9.25 11.6 14.1 17.65 21.45 24.95 28.95 33.75 38.75
max. 10.75 13.4 15.9 19.75 23.55 27.05 31.05 36.25 41.25
r min. 0.6 0.8 0.8 1 1 1.2 1.6 2 2
s nom. = max. 24 30 36 46 55 65 75 85 95
min. 23.16 29.16 35 45 53.8 63.1 73.1 82.8 92.8
f nom. 8 10 12 15 18 21 24 28 32
min. 7.25 9.25 11.1 14.1 17.1 19.95 22.95 26.95 30.75
max. 8.75 10.75 12.9 15.9 18.9 22.05 25.05 29.05 33.25
v max. 16.7 20.84 24.84 30.84 37 43 49 57.2 65.2
min. 15.3 19.16 23.16 29.16 35 41 47 54.8 62.8
x max. 5 6.3 7.5 9 10 11 12.5 14 15
NOTEDimensions are in millimetres.
BS 7419
:
1991
© BSI 12-1999
3
1)
Incomplete threads, u k 2p.
Figure 1 — Dimensions of square head bolts
BS 7419
:
1991
4
© BSI 12-1999
Table 2 — Dimensions of hexagon head bolts
Thread (d) M16 M20 M24 M30 M36 M42 M48 M56 M64
P (pitch)

2 2.5 3 3.5 4 4.5 5 5.5 6
b max. 122 127.5 133 140.5 148 155.5 163 172.5 182
min. 116 120 124 130 136 142 148 156 164
c max. 0.8 0.8 0.8 0.8 0.8 1 1 1 1
d
a
max. 18.7 24.4 28.4 35.4 42.4 48.6 56.6 67 75
d
s
max. 16.7 20.84 24.84 30.84 37 43 49 57.2 65.2
min. 15.3 19.16 23.16 29.16 35 41 47 54.8 62.8
d
w
min. 22 27.7 33.25 42.75 51.11 59.95 69.45 78.66 88.16
e min. 26.17 32.95 39.55 50.85 60.79 71.3 82.6 93.56 104.86
k nom. 10 12.5 15 18.7 22.5 26 30 35 40
min. 9.25 11.6 14.1 17.65 21.45 24.95 28.95 33.75 38.75
max. 10.75 13.4 15.9 19.75 23.55 27.05 31.05 36.25 41.25
r min. 0.6 0.8 0.8 1 1 1.2 1.6 2 2
s nom. = max. 24 30 36 46 55 65 75 85 95
min. 23.16 29.16 35 45 53.8 63.1 73.1 82.8 92.8
x max. 5 6.3 7.5 9 10 11 12.5 14 15
NOTEDimensions are in millimetres.
BS 7419
:
1991
© BSI 12-1999
5
1)
Incomplete threads, u k 2p.

Dimension is in millimetres.
Figure 2 — Dimensions of hexagon head bolts
BS7419:1991
6
© BSI 12-1999
Table 3 — Tolerance on nominal length l
Table 4 — Preferred sizes
3 Characteristics
Materials, tolerances, mechanical properties and
associated nuts for holding down bolts shall be as
given inTable 5.
4 Complete designation for the
purpose of an enquiry or order
When designating for the purpose of an enquiry or
order, the following information shall be given:
a) general product description, i.e. Holding down
bolts;
b) head form, i.e. Square square, or Hexagon;
c) the letter “M” indicating that the product is
ISO metric;
d) the nominal size (thread diameter) of the
product in millimetres;
e) the nominal length in millimetres;
f) the strength grade;
g) the number of this British Standard,
i.e.BS7419;
h) details of the associated nut in accordance with
the appropriate British Standard, i.e. BS4190,
BS3962 or BS4395-1;
i) details of the coating (if required), in

accordance with the appropriate British
Standard (e.g. BS729, BS1706, BS4921).
Examples:
Square head holding down bolts20mm in
diameter,450mm long, strength grade4.6with
nuts to BS4190 would be designated:
1) Holding down bolts, Square square
M20× 450, 4.6 to BS7419, nuts to BS4190.
Hexagon head pre-loaded holding down
bolts24mm in diameter, 600mm long, strength
grade 8.8, nuts to BS4395-1, galvanized would be
designated:
2) Pre-loaded holding down bolts, Hexagon
M24× 600, 8.8 to BS7419, nuts to BS4395-1,
galvanized to BS729.
Table 5 — Characteristics
Nominal length Tolerance
mm mm
250 k l k 315 ± 5.20
315 < l k 400 ± 5.70
400 <l k 500 ± 6.30
500 <l k 625 ± 6.80
625 <l k 800 ± 7.20
800 <l k 1 000 ± 7.40
1 000 <l k 1 250 ± 7.60
Nominal length l for thread (d):
M16 M20 M24 M30 M36
mm mm mm mm mm
300 300 — — —
375 375 375 — —

450 450 450 450 450
525 525 525 525 525
600 600 600 600 600
— 750 750 750 750
— 1 000 1 000 1 000 1 000
— — 1 250 1 250 1 250
Material Steel
Thread tolerance 8g (seeBS 3643-1 and BS 3643-2)
Mechanical property class
a
d k 39mm: 4.6, 8.82) (see BS6104-1)
d >39mm: as agreed
Tolerance (for product grade C) See BS6322-1
Finish a) as processed
b) galvanized to BS1706
c) sherardized to BS4921
d) electroplated to BS1706
Acceptability For acceptance procedure, see BS6587
Associated nuts
b
See BS4190 or BS3692
a
The designation symbol for the property classes according to BS 6104-1 can also be used for thread sizes above M39, provided that
the finished product has all the properties assigned to the designation symbols in BS 6104-1.
b
When bolts of property class 8.8 are to be preloaded, nuts and hardened washers in accordance with BS4395-1 should be
specified.
BS7419:1991
© BSI 12-1999
Publication(s) referred to

BS 729, Specification for hot dip galvanized coatings on iron and steel articles.
BS 1706, Method for specifying electroplated coatings of zinc and cadmium on iron and steel.
BS 3643, ISO metric screw threads.
BS 3643-1, Principles and basic data.
BS 3643-2, Specification for selected limits of size.
BS 3692, Specification for ISO metric precision hexagon bolts, screws and nuts. Metric units.
BS 4190, Specification for ISO metric black hexagon bolts, screws and nuts.
BS 4395, Specification for high strength friction grip bolts and associated nuts and washers for structural
engineering.
BS 4395-1, General grade.
BS 4921, Specification for sherardized coatings on iron or steel.
BS 6104, Mechanical properties of fasteners.
BS 6104-1, Specification for bolts, screws and studs.
BS 6322, Tolerances for fasteners.
BS 6322-1, Specification for tolerances for bolts, screws and nuts with thread diameters U 1.6mm
andk 150mm and product grades A, B and C.
BS 6565, Method for dimensioning and designating bolts, screws, studs and nuts.
BS 6587, Method of acceptance inspection for fasteners.
BS7419:1991
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