BS 3597:1984

Foreword
Committees responsible
Specification
1 Scope
2 Definition
3 Information to be supplied by the purchaser to the
   electroplater
4 Coating classification
5 Sampling
6 Heat treatment of steel
7 Undercoats
8 Coatings
Appendices
A Guidance information
B Determination of local undercoat thickness and
   coating thickness
C Adhesion test (thermal shock method)
D Sulphur dioxide porosity test
Tables
1 Service condition and related recommended coating
   thickness
2 Oven temperature
Figures
1 Cabinet with door
2 Hooded cabinet

Requirements for appearance, heat treatment, sampling and undercoats for tin/nickel alloy coatings on fabricated articles of metal and on printed circuit boards. Classifies the coatings. Specifies requirements and test methods for thickness, adhesion and porosity. Lists information to be supplied by a purchaser to the electroplater.

This British Standard specifies requirements for electroplated coatings of the intermatallic compound SnNi.

NOTE 1. Such coatings are generally recognized as being hard and wear- and corrosion-resistant.

The coatings are intended for use on ferrous and non-ferrous basis metals and also on printed wiring boards.

A classification scheme is included by which the nature of the basis metal and undercoat, if any, and the tin/nickel coating thickness can be defined.

This standard does not specify any requirements for the condition, finish or surface roughness of the basis material before electroplating (see A.3).

NOTE 2. Attention is drawn to BS 9760. which specifies capability approval procedure and rules for printed circuits of assessed quality.

The standard is not applicable to electroplating of:

1. threaded components;
2. sheet, strip or wire in the unfabricated form, or of coil springs;
3. steels with tensile strengths greater than 1000 MPa, because such steels require hydrogen embrittlement relief after plating (see clause 6).

NOTE 3. The titles of the publications referred to in this standard are listed on the inside back cover.