BS 3692:2014

Foreword
1 Scope
2 Normative references
3 Information and requirements to be agreed and documented
4 General dimensions
5 Length of bolts and screws
6 Ends of bolts and screws
7 Screw threads
8 Length of thread on bolts and screws
9 Dimensions of bolts and screws
10 Angularity and eccentricity of bolts, screws and nuts
11 Dimensions of nuts
12 Chamfering, washer facing and countersinking bolts,
   screws and nuts
13 Material and manufacture of steel bolts and screws
14 Mechanical properties of steel bolts and screws
15 Strength grade designation system for steel nuts
16 Material and manufacture of steel nuts
17 Mechanical properties of steel nuts (excluding thin nuts)
18 Drilled bolts with split pin holes
19 Finishes
20 Marking and identification
21 Inspection and testing
Annexes
Annex A (informative) - Strength grade designation system for steel
        bolts and screws
Annex B (informative) - Recommended gauge for checking squareness
        of thread to face of nut
Annex C (normative) - Testing of mechanical properties of steel nuts
Annex D (informative) - Association of bolt and screw lengths and
        diameters
Annex E (informative) - Basis for the derivation of tolerances
Annex F (informative) - Manufacturer's recommended range of sizes
Bibliography

Provides the general dimensions and tolerances of precision hexagon bolts, screws and nuts with ISO metric threads in diameters from 1.6 mm to 68 mm inclusive.

This standard gives the general dimensions and tolerances of precision hexagon bolts, screws and nuts with ISO metric threads in diameters from 1.6mm to 68mm inclusive.

This standard specifies mechanical properties of bolts, screws and nuts made of carbon steel and alloy steel when tested at an ambient temperature range of 10°C to 35°C.

NOTE1 Fasteners (the term used when bolts, screws and nuts are considered all together) that conform to the requirements of this standard are evaluated at this ambient temperature range. They might not retain the specified mechanical and physical properties at elevated temperatures and/or lower temperatures.

This standard is not applicable to fasteners used in applications outside of the range−50°C to+150°C.

NOTE2 Fasteners conforming to the requirements of this standard are used in applications ranging from−50°C to+150°C. The use of fasteners in applications outside of this range, and up to a maximum temperature of+300°C, might need to be based on the advice of an experienced fastener metallurgist for determining appropriate choices for a given application.

NOTE3 Nuts in accordance with this standard cannot be fully loaded with sufficient assurance up to the yield point of the appropriate bolt, or beyond this, without the possibility of the nut thread being stripped, and for this reason it is essential that new designs of nuts for use with BS3692 bolts and studs conforming to this standard conform to BSENISO898‑2.

NOTE4 Nuts with an effective height of less than 0.6d and/or with a width across flats or outside diameter of less than 1.4d are excluded from the mechanical requirements specified.

The dimensional requirements of this British Standard are also applicable to non-ferrous and stainless steel bolts, screws and nuts.

Information on strength grade designation system for steel bolts and screws can be found in AnnexA.

NOTE5 The range of nominal sizes included in this British Standard is likely to be adequate for most of the applications for which this series is likely to be employed, but for the convenience of users requiring larger sizes, further information in relation to the derivation of tolerances is in AnnexE.

NOTE6 In addition to the definitive requirements, this standard also requires the items detailed in Clause3 to be documented. For compliance with this standard, both the definitive requirements and the documented items have to be met.