Metal Reference Guide

Ethical Sourcing

Recognizing the challenges associated with providing precious materials in a responsible manner, we work closely with our suppliers to ensure our jewelry is produced in the most ethical way possible.

Responsible Supply Chain of Minerals from Conflict-Affected and High-Risk Areas

To view our company policy and company management system for a responsible supply chain of minerals from conflict-affected and high-risk areas, click the link below.

Recycled Silver - As part of our sustainability program, JK Findings only buys Green Silver for use in our production process. All of our .925 silver items are nickel free.


Gold Filled

Gold Filled Diagram

Gold filled uses a karat gold overlay which is then bonded to a brass inner core. JK Findings manufactures gold filled with 1/20th 14 karat gold, meaning, it is 5% 14 karat gold by weight with a brass inner core. We offer 1/20 14K yellow gold filled and 1/20 14K rose gold filled.

1/20 14K Gold Filled

1/20 14K Gold Filled vs. 1/20 12K Gold Filled

Customers often compare 12K Gold Filled to 14K Gold Filled. Other than the difference in the karat gold composition, there are some visual differences between the two versions. Below are images of beads in both 1/20 14K Gold Filled and 1/20 12K Gold Filled for comparison.

The 4004730 Beads are made from 1/20 14KGF and the 4504730 Beads are made from 1/20 12KGF. The 12KGF beads are slightly lighter and less yellow in color than the 14KGF beads.

1/20 14K Gold Filled vs. 1/20 12K Gold Filled

Gold Filled Wire: Our 1/20 14K Gold Filled wire has the following specifications:

  • Density of 4.69 oz/cubic inch
  • Annealing Temperature of 510°C with a Dwell Time of 20min - 60min depending on the size of the furnace load (hardness testing after annealing is best way to confirm annealed state)
  • Melting Range of >760°C

To learn more about gold filled, view our What is Gold Filled flyer.

For more information on the difference between plating and gold filled, visit www.jvclegal.org.

For information on Stamping and Marking Regulations, visit www.mjsa.org.

U.S. Gold Filled Tolerances*

Karatage

Minimum Purity Required

Tolerance

Minimum Purity Required with Tolerance

1/20 14K

.0292

.003

.0262

1/20 12K

.0250

.003

.0220

1/20 10K

.0208

.003

.0178

*JK Findings adheres to U.S. Gold Filled Tolerances, which may differ from standards used in other countries.

JK Findings Gold Plating- Regular Plating vs Hamilton Plating

Customers sometimes ask us for items with a brighter yellow color which is often referred to as Hamilton Plating. Below are images of a chain sample with our Regular Plate and Hamilton Plate for comparison.

We currently offer some of our Chains, Bracelets, Lobster Claws, Trigger Clasps and Spring Rings with Hamilton plating. If you have other items that you would like us to offer in Hamilton please contact us.

Regular Plating vs Hamilton Plating


Gold

We offer 9K, 10K, 14K, and 18K gold findings in white or yellow.

Karat Weight

Gold Purity

9K

.375

10K

.417

14K

.585

18K

.750

Gold Items

U.S. Gold Tolerances*

Karatage

Minimum Purity Required

Tolerance

Minimum Purity Required with Tolerance

 

 

without solder

with solder

without solder

with solder

24K

.9995

.003

.007

.9965

.9925

18K

.7500

.003

.007

.7470

.7430

14K

.5833

.003

.007

.5803

.5763

10K

.4167

.003

.007

.4137

.4097

9K

.3750

.003

.007

.3720

.3680

*JK Findings adheres to U.S. Gold Tolerances, which may differ from standards used in other countries.


Silver

Silver

All silver items contain a minimum of .925 silver (the remaining balance is made up of copper). As part of our sustainability program, JK Findings only buys Green Silver for use in our production process. All of our .925 silver items are nickel free.


Terminology

Conversion Factors

To Go From

To

Multiply By

Carats

Pennyweights (DWT)

0.128603

Carats

Grams

0.2

Feet

Millimeters

304.8

Feet

Meters

0.3048

Grams

Carats

5

Grams

Pennyweights (DWT)

0.6430149

Grams

Troy Ounces

0.03215075

Inches

Millimeters

25.4

Inches

Meters

0.0254

Millimeters

Inches

0.03937008

Millimeters

Feet

0.00328084

Meters

Inches

39.37008

Meters

Feet

3.28084

Pennyweights (DWT)

Carats

7.775869

Pennyweights (DWT)

Grams

1.555174

Pennyweights (DWT)

Troy Ounces

0.05

Troy Ounces

Pennyweights (DWT)

20

Troy Ounces

Grams

31.10348


Vickers Hardness Scale

Wire Hardness

B & S No.

Fractional

Description

Cold Work %

DS

0

Dead Soft

Annealed

1

1/4

Soft

10.7

2

1/2

Medium

20.7

3

3/4

Med-Hard

29.4

4

Full

Hard

37.1

5

 

 

44.1

6

 

Extra Hard

50.1

7

 

 

56.2

8

 

Spring Hard

60.5

9

 

 

65.1

10

 

Extra Spring Hard

68.6

11

 

 

72.1

12

 

Special Spring Hard

75.1

13

 

 

77.5

14

 

Super Spring Hard

80.3


Wire Diameter

Inch

Millimeter

Gauge

 

Inch

Millimeter

Gauge

0.004

0.1

38

 

0.036

0.91

19

0.0045

0.11

37

 

0.04

1.02

18

0.005

0.13

36

 

0.045

1.15

17

0.0056

0.14

35

 

0.051

1.29

16

0.0063

0.16

34

 

0.057

1.45

15

0.0071

0.18

33

 

0.064

1.63

14

0.008

0.2

32

 

0.072

1.83

13

0.009

0.23

31

 

0.081

2.05

12

0.01

0.26

30

 

0.091

2.3

11

0.011

0.29

29

 

0.102

2.59

10

0.013

0.32

28

 

0.114

2.91

9

0.014

0.36

27

 

0.128

3.26

8

0.016

0.41

26

 

0.144

3.66

7

0.018

0.46

25

 

0.162

4.12

6

0.02

0.51

24

 

0.182

4.62

5

0.023

0.58

23

 

0.208

5.19

4

0.025

0.64

22

 

0.229

5.83

3

0.028

0.72

21

 

0.258

6.54

2

0.032

0.81

20

 

0.289

7.35

1


Conversion Grid to Estimate an Item Weight in Different Metals

To use this grid, locate intersection of desired metal and present metal. This number is your conversion factor. Multiply that number by actual known weight of present metal, e.g., to determine what an item that weighs 1.50 dwt in Sterling would weigh in 14K Yellow, go to 14K Yellow under Desired Metal column. Follow that row across until it intersects the Sterling column. This is your conversion factor (in this case 1.248). Then multiply that number 1.248 (conversion factor) by 1.5 (known weight) = 1.872 dwt. This would be the weight for the 14K Yellow item.

Present Metal

Desired Metal

 

10K YELLOW

10K WHITE

14K YELLOW

14K WHITE

18K YELLOW

18K WHITE

STERLING SILVER

PLATINUM

10% Ir PLATINUM

ALLOY

24K FINE GOLD

10K YELLOW

1

1.045

0.885

0.918

0.743

0.79

1.105

0.539

0.537

1.377

0.599

10K WHITE

0.957

1

0.847

0.878

0.711

0.756

1.057

0.516

0.514

1.318

0.573

14K YELLOW

1.13

1.181

1

1.036

0.839

0.893

1.248

0.609

0.607

1.556

0.677

14K WHITE

1.09

1.139

0.965

1

0.809

0.861

1.204

0.588

0.585

1.501

0.653

18K YELLOW

1.347

1.407

1.192

1.236

1

1.064

1.488

0.726

0.723

1.855

0.806

18K WHITE

1.265

1.322

1.12

1.161

0.94

1

1.398

0.683

0.68

1.743

0.758

STERLING SILVER

0.905

0.946

0.801

0.83

0.672

0.715

1

0.488

0.486

1.246

0.542

PLATINUM

1.854

1.938

1.641

1.701

1.377

1.465

2.049

1

0.996

2.554

1.11

10% Ir Pt.

1.862

1.946

1.648

1.708

1.383

1.471

2.057

1.004

1

2.564

1.115

ALLOY

0.726

0.759

0.643

0.666

0.539

0.574

0.802

0.392

0.39

1

0.435

24K Fine Gold

1.67

1.745

1.478

1.532

1.24

1.32

1.845

0.901

0.897

2.3

1