# The Weights Regulations 1986, Regulation 5: Shape


(1) Except as provided by paragraph (2) of this Regulation, a weight shall only be of a type or form mentioned in the following Table in relation to a weight of its purported mass:—
Type or form
Weights which may be of that type or form
1. Metric weights (other than carat (metric) weights)
(i) The irregular octahedronal form described in Schedule 2 to these Regulations.
Weights of 25 kg.
(ii) The rectangular form described in that Schedule.
Weights of 5 kg, 10 kg or 20 kg.
(iii) The cylindrical form described in that Schedule.
Weights of not more than 10 kg nor less than 20 g and of 10, 5, 2 and 1 g.
(iv) The hexagonal form described in that Schedule.
Weights of not more than 2 kg nor less than 100 g.
(v) The disc form described in that Schedule.
Weights of not more than 50 g nor less than 1 g.
(vi) Flat type.
Weights of not more than 1 g nor less than 10 mg.
(vii) Wire type.
Weights of 50 mg or less.
2. Carat (metric) weights
(i) Cylindrical with a knob.
Weights of 5 C.M. or more.
(ii) Flat type.
Weights of not more than 20 C.M. nor less than 0.05 C.M.
(iii) Wire type.
Weights of 0.25 C.M. or less.
3. Imperial weights (other than weights in paragraphs 4 and 5 of this Table)
(i) Bell, bar, flat-circular or ring type.
Any weight other than a weight of 50, 20, 10 or 5 lb.
(ii) Octagonal type.
Weights of 50, 20, 10 or 5 lb.
4. Weights expressed as multiples or fractions of 1/7000 lb
Flat or wire type.
All such weights.
5. Ounce troy weights
(i) Cylindrical with a carrying handle or knob.
Weights of 1 oz tr or more.
(ii) Flat or wire type.
Weights of 0.5 oz tr or less.
(2) Nothing in paragraph (1) of this Regulation or Schedule 2 to these Regulations shall preclude any weight from being regarded as fit for use for trade by reason of the fact that one or more edges are chamfered or rounded.

---
Source: https://www.legislation.gov.uk/uksi/1986/1683/regulation/5 (the official version)
Page: https://openlegislation.uk/weights-regulations-1986/regulation-5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.