Helpful Guides and Charts for Jewelry & Beads

Standard Necklace Lengths

Equivalents

Inches to Millimeters

Wire Gauge in Inches and Millimeters

How Many Beads Per Inch

Seed Bead Sizes

Glass Bead Surfaces & Finishes

Plating (Standards and Abbreviations)
Standard Necklace Lengths
Choker 16 inches
Princess 18 inches
Matinee 24 inches
Opera 32 inches
Rope 48 inches
Equivalents
1 Carat = 5 Grams
1000 Grams = 1 Kilogram
1 Mass = 1200 pieces
1 Mille = 1000 pieces
1 Ounce = 28 grams
16 oz. = 1 Pound
448 Grams = 1 Pound
1 Gross = 144 pieces
Troy Ounce = 31.1 Grams (applies to Precious Metals)
Gold Filled = A layer of Gold bonded to a base metal. Usually brass is used
1 Kilo = 1000 Grams Or 2.2 Pounds Or 36 Ounces Per Kilo
Inches to Millimeters
Inches
Millimeters
1/16 in. 1.5mm
1/8 in. 3mm
1/4 in. 6mm
3/8 in. 9mm
1/2 in. 12mm
5/8 in. 15mm
3/4 in. 18.5mm
7/8 in. 22mm
1 in. 25mm
go to our metric conversion page for an instant exact conversion

Wire Gauge in Inches and Millimeters
Determine the diameter, in inches or millimeters, of wire gauges from 10 to 38 gauge.

Gauge

Inches

Millimeters

10

0.102

2.59

11

0.091

2.31

12

0.081

2.06

13

0.072

1.83

14

0.064

1.63

15

0.057

1.45

16

0.052

1.29

17

0.045

1.14

18

0.04

1.02

19

0.036

0.91

20

0.032

0.81

21

0.028

0.71

22

0.025

0.64

23

0.023

0.58

24

0.02

0.51

25

0.0179

0.455

26

0.0159

0.404

27

0.0142

0.361

28

0.0126

0.32

29

0.0113

0.287

30

0.01

0.25

31

0.0089

0.226

32

0.008

0.2

33

0.0071

0.18

34

0.0063

0.16

35

0.0056

0.142

36

0.005

0.13

37

0.0045

0.114

38

0.004

0.1
How Many Beads Per Inch
Bead Size
Per Inch
7"
16"
24"
32"
36"
4mm
6.25
43
100
150
200
225
5mm
5.00
35
82
124
160
180
6mm
4.25
28
67
100
132
153
7mm
3.50
24
57
85
114
126
8mm
3.25
22
50
75
100
112
10mm
2.50
18
40
60
80
90
12mm
2.00
15
33
50
66
72
14mm
1.75
13
29
43
56
63
16mm
1.50
11
25
38
50
54
18mm
1.25
10
23
34
45
50
20mm
1.20
8
20
29
38
43
Seed Bead Sizes
Aught Size
mm diameter
beads per inch
6/0
3.30
10
8/0
2.50
13
9/0
2.20
15
10/0
2.00
16
11/0
1.80
20
13/0
1.50
27
14/0
1.40
24
15/0
1.30
25
Seed beads are sized in aughts, which are different than millimeters. The most popular school of thought of the sizing of seed beads states that the size (6/0) refers to the number of seed beads per inch (6 beads per inch). Another sizing theory is that the size is based on the rod used to make the beads. The larger the number, the smaller the bead (20 is small, 3 is large).
Glass Bead Surfaces & Finishes
Opaque Light cannot pass through
Transparent

Light can pass through
Translucent Allows partial transmission of light
Matte Dull appearance, achieved by tumbling beads or dipping in a glass etching solution
Silver lined

Have a mirror like finish inside, which adds sparkle to the bead
Color lined Usually seen in a two color mix with an opaque color inside of a transparent bead
Luster A very shiny finish covering the entire outer layer of the bead
Dyed A process of surface color dying often seen in Japanese beads. Color will come off if you do ot protect them
Metallic Bead surface has a fired on metal like finish
AB (Aurora Borealis) A rainbow like surface which has been fired onto the bead
Plating (Standards and Abbreviations)
SC Silver color metal
GC Gold color metal
SP

Silver plated finish- over a base metal for a sterling silver appearance
GP Gold plated finish-over a base metal for a 14k gold appearance
SS Sterling Silver-.925 actual silver content
GF Gold filled - a layer of 12k or 14k gold, mnilled to a ase metal for a long lasting gold appearance
14K .585 actual gold content
18K .750 actual gold content