# The Weights Regulations 1986, Schedule 4: PRESCRIBED LIMITS OF ERROR


TABLE 1
Metric except carat (metric) weights of not less than 50 mg
1.
2.
3.
Purported mass of the weight
Prescribed limits of error on passing as fit for use for trade (+ only)
Prescribed limits of error in relation to the obliteration of the stamp (±)
25 kg
4000 mg
4000 mg
20 kg
3200 mg
3200 mg
10 kg
1600 mg
1600 mg
5 kg
800 mg
800 mg
2 kg
400 mg
400 mg
1 kg
200 mg
200 mg
500 g
100 mg
100 mg
200 g
50 mg
50 mg
100 g
30 mg
30 mg
50 g
30 mg
30 mg
20 g
20 mg
20 mg
15 g
20 mg
20 mg
10 g
20 mg
20 mg
5 g
10 mg
10 mg
4 g
10 mg
10 mg
3 g
5 mg
5 mg
2 g
5 mg
5 mg
1 g
5 mg
5 mg
500 mg
2.5 mg
2.5 mg
400 mg
2.5 mg
2.5 mg
300 mg
2 mg
2 mg
200 mg
2 mg
2 mg
150 mg
2 mg
2 mg
100 mg
1.5 mg
1.5 mg
50 mg
1.2 mg
1.2 mg
TABLE 2
Metric except carat (metric) weights of not more than 20 mg
1.
2.
3.
Purported mass of the weight
Prescribed limits of error on passing as fit for use for trade (±)
Prescribed limits of error in relation to the obliteration of the stamp (±)
20 mg
0.3 mg
0.6 mg
10 mg
0.25 mg
0.5 mg
5 mg
0.2 mg
0.4 mg
2 mg
0.2 mg
0.4 mg
1 mg
0.2 mg
0.4 mg
TABLE 3
Carat (metric) weights
1.
2.
3.
Purported mass of the weight
Prescribed limits of error on passing as fit for use for trade (±)
Prescribed limits of error in relation to the obliteration of the stamp (±)
500 C.M.
5.0 mg
10.0 mg
200 C.M.
3.0 mg
6.0 mg
100 C.M.
2.5 mg
5.0 mg
50 C.M.
2.0 mg
4.0 mg
20 C.M.
1.5 mg
3.0 mg
10 C.M.
1.2 mg
2.4 mg
5 C.M.
1.0 mg
2.0 mg
2 C.M.
0.7 mg
1.4 mg
1 C.M.
0.6 mg
1.2 mg
0.5 C.M.
0.5 mg
1.0 mg
0.25 C.M.
0.4 mg
0.8 mg
0.2 C.M.
0.4 mg
0.8 mg
0.1 C.M.
0.3 mg
0.6 mg
0.05 C.M.
0.2 mg
0.4 mg
0.02 C.M.
0.2 mg
0.4 mg
0.01 C.M.
0.2 mg
0.4 mg
TABLE 4
Avoirdupois weights
1.
2.
3.
Purported mass of the weight
Prescribed limits of error on passing as fit for use for trade (+ only)
Prescribed limits of error in relation to the obliteration of the stamp (±)
56 lb
4000 mg
4000 mg
50 lb
3600 mg
3600 mg
28 lb
2000 mg
2000 mg
20 lb
1500 mg
1500 mg
14 lb
1000 mg
1000 mg
10 lb
750 mg
750 mg
7 lb
560 mg
560 mg
5 lb
450 mg
450 mg
4 lb
360 mg
360 mg
2 lb
180 mg
180 mg
1 lb
100 mg
100 mg
8 oz
60 mg
60 mg
4 oz
35 mg
35 mg
2 oz
30 mg
30 mg
1 oz
25 mg
25 mg
1/2 oz
20 mg
20 mg
1/4 oz
15 mg
15 mg
1/8 oz
10 mg
10 mg
1/16 oz
5 mg
5 mg
1/32 oz
5 mg
5 mg
TABLE 5
Weights expressed as multiples or fractions of 1/7000 lb
1.
2.
3.
Purported mass of the weight
Prescribed limits of error on passing as fit for use for trade (±)
Prescribed limits of error in relation to the obliteration of the stamp (±)
100
1.65 mg
3.30 mg
50
1.32 mg
2.64 mg
30
1.20 mg
2.40 mg
20
1.06 mg
2.12 mg
10
0.86 mg
1.72 mg
5
0.68 mg
1.36 mg
3
0.60 mg
1.20 mg
2
0.53 mg
1.06 mg
1
0.43 mg
0.86 mg
0.5
0.34 mg
0.68 mg
0.3
0.30 mg
0.60 mg
0.2
0.27 mg
0.54 mg
0.1
0.21 mg
0.42 mg
0.05
0.20 mg
0.40 mg
0.03
0.20 mg
0.40 mg
0.02
0.20 mg
0.40 mg
0.01
0.20 mg
0.40 mg
TABLE 6
Ounce troy weights
1.
2.
3.
Purported mass of the weight
Prescribed limits of error on passing as fit for use for trade (±)
Prescribed limits of error in relation to the obliteration of the stamp (±)
500 oz tr
780 mg
1560 mg
400 oz tr
620 mg
1240 mg
300 oz tr
465 mg
930 mg
200 oz tr
310 mg
620 mg
100 oz tr
155 mg
310 mg
50 oz tr
80 mg
160 mg
40 oz tr
60 mg
120 mg
30 oz tr
50 mg
100 mg
20 oz tr
30 mg
60 mg
10 oz tr
15 mg
30 mg
5 oz tr
8 mg
16 mg
4 oz tr
6 mg
12 mg
3 oz tr
5 mg
10 mg
2 oz tr
3.5 mg
7 mg
1 oz tr
2.7 mg
5.4 mg
0.5 oz tr
2.3 mg
4.6 mg
0.4 oz tr
2.1 mg
4.2 mg
0.3 oz tr
1.9 mg
3.8 mg
0.2 oz tr
1.6 mg
3.2 mg
0.1 oz tr
1.3 mg
2.6 mg
0.05 oz tr
1.1 mg
2.2 mg
0.04 oz tr
1.0 mg
2.0 mg
0.03 oz tr
1.0 mg
2.0 mg
0.025 oz tr
0.9 mg
1.8 mg
0.02 oz tr
0.8 mg
1.6 mg
0.01 oz tr
0.7 mg
1.4 mg
0.005 oz tr
0.6 mg
1.2 mg
0.004 oz tr
0.5 mg
1.0 mg
0.003 oz tr
0.5 mg
1.0 mg
0.002 oz tr
0.4 mg
0.8 mg
0.001 oz tr
0.3 mg
0.6 mg

---
Source: https://www.legislation.gov.uk/uksi/1986/1683/schedule/4 (the official version)
Page: https://openlegislation.uk/weights-regulations-1986/schedule-4
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.