Author: R&M Fine Inc

Metals Explained: 10k, 14k, 18k and all the metals we cast at R&M Fine Inc.

When manufacturing fine jewelry, understanding the difference between karat golds and other casting metals is critical for quality, durability, pricing, and long term performance. At R&M Fine Inc, we specialize in professional jewelry casting using 10K, 14K, and 18K gold, as well as sterling silver, platinum, and brass for designers, retailers, and wholesale brands across the United States.

This guide explains the difference between all gold karats and highlights the additional metals we cast in house.

Flasks in the oven ready for casting. This process is known as lost wax casting.
A tree or button melting and being reused to cast new jewelry.
Casted trees in flasks during the cooling process.
Trees cut down to be reused to make new castings.

What Is Karat Gold?

Karat (K) measures the purity of gold in a metal alloy. Pure gold is 24K, meaning it contains 99.9 percent gold. However, 24K gold is extremely soft and not practical for most jewelry manufacturing applications. To improve durability and structural integrity, pure gold is alloyed with metals such as copper, silver, zinc, or palladium. Zinc isn’t used as often now, but it can be found in jewelry made within the last 20 years.

The lower the karat, the higher the percentage of strengthening alloys. The higher the karat, the richer the gold content. Comparatively the higher the gold karat (purity) the softer the casted metal will be, this is why you can bend jewelry made of 22 and 24 kt so easily.

10K Gold: Durable and Cost Effective

Gold Content: 41.7 percent
Stamp: 417 in Europe and 10KT in the United States

10K gold contains 41.7 percent pure gold and 58.3 percent alloy metals. It is the most durable and hardest of the commonly used gold alloys.

Benefits of 10K Gold

  • Highly resistant to scratching and bending
  • Lower material cost per gram
  • Ideal for high wear jewelry
  • Excellent for commercial production

Because of its strength and affordability, 10K gold is often used in everyday jewelry collections and high volume retail lines.

14K Gold: The Industry Standard

Gold Content: 58.5 percent
Stamp: 585 in Europe and 14KT in the United States

14K gold is the most popular gold alloy in the United States. It offers an ideal balance between purity and durability.

Benefits of 14K Gold

  • Rich gold color
  • Strong structural integrity
  • Excellent for stone setting
  • Widely recognized in bridal and fine jewelry

For engagement rings, wedding bands, and fine jewelry collections, 14K gold provides both long term durability and strong consumer appeal.

18K Gold: High Purity and Luxury Appeal

Gold Content: 75 percent
Stamp: 750 in Europe and 18KT in United States

18K gold contains 75 percent pure gold, making it significantly richer in color and intrinsic value.

Benefits of 18K Gold

  • Deep, saturated gold tone
  • Higher precious metal value
  • Preferred for luxury and designer collections
  • Popular in international markets

Because it contains more pure gold, 18K is softer than 14K and 10K. It is best suited for premium pieces where luxury and color are prioritized.

Sterling Silver

Composition: 92.5 percent silver
Stamp: 925 and STER

Sterling silver is one of the most versatile precious metals used in jewelry manufacturing. It offers excellent detail reproduction and a bright white finish.

Advantages of Sterling Silver

  • Lower raw material cost
  • Ideal for fashion and entry level fine jewelry
  • Strong compatibility with plating
  • Suitable for high volume production

Platinum Casting

Common Alloys: 900Pt or 950Pt

Platinum is a dense, naturally white precious metal known for its strength and longevity. Unlike white gold, platinum does not require rhodium plating to maintain its color.

Advantages of Platinum

  • Heavier weight and premium feel
  • Superior prong security for diamonds
  • Hypoallergenic properties
  • Long term durability

Platinum casting requires higher temperatures and precise alloy control. Our team is experienced in managing platinum shrinkage rates and finishing requirements for high end jewelry production but only cast 90/10 Platinum Iridium.

Brass Casting for Development and Fashion Jewelry

Brass is a copper and zinc alloy commonly used in jewelry prototyping and fashion collections.

Brass

  • Cost effective for sampling
  • Excellent for mold testing
  • Ideal for large production runs
  • Suitable for plating.

Many brands use brass during product development before transitioning designs into gold, sterling silver, or platinum. This step can help keep development costs low. We also cater to larger brands who manufacture costume and high end brass jewelry.

Choosing the Right Metal for Your Jewelry

When selecting a metal for your jewelry line, consider:

  • Target retail price
  • Target market
  • Market positioning
  • Durability requirements
  • Stone setting type
  • Weight preference
  • Long term wear expectations

Each alloy behaves differently during casting, polishing, setting, and finishing. Working with an experienced jewelry casting manufacturer such as ourselves ensures consistent quality and structural integrity across production runs.

Professional Jewelry Casting at R&M Fine Inc

R&M Fine Inc provides full service jewelry casting and manufacturing support, including:

  • CAD to casting production
  • 10K, 14K, 18K, and 22k gold castings in yellow, white, and rose
  • Sterling silver casting
  • Platinum casting
  • Brass prototyping and production casting
  • Quality control and finishing
  • Stone setting and final assembly

Whether you are launching a bridal collection, expanding a wholesale jewelry line, or developing a new designer capsule, our team helps you select the right metal to match your vision and your customer’s expectations.

If you are searching for a reliable jewelry casting company specializing in gold, silver, platinum, and brass, contact R&M Fine Inc to discuss your next project.

The Precision Power of Laser Welding in Fine Jewelry

Why Laser Soldering Is a Game-Changer in Fine Jewelry Manufacturing and Repairs

In the world of fine jewelry, precision and craftsmanship are everything. Whether you’re manufacturing a custom engagement ring or repairing a delicate antique piece, traditional soldering methods can pose challenges when working with intricate designs or heat-sensitive gemstones.

That’s where laser welding and soldering come in — offering jewelers a safer, cleaner, and more precise way to bond metals without compromising detail.

At R&M Fine Inc, we utilize the Orion laser welder to elevate the quality, speed, and precision of our custom jewelry production and repair work.

What Is Laser Soldering and Welding?

Laser welding is a non-contact process that uses a focused beam of light to fuse metals together at high temperatures. Unlike traditional torch soldering, the heat is incredibly localized — often within microns of the target — making it ideal for working on prongs, jump rings, bezels, and other tight spaces.

Key Benefits of Laser Welding for Fine Jewelry

  • Precision Without Damage
    Laser welding allows us to work right next to gemstones (even heat-sensitive ones like opals or emeralds) without removing them. This minimizes risk, saves time, and preserves the integrity of the piece.
  • Stronger, Cleaner Joints
    The welds created by the Orion laser welder are stronger and cleaner than those made with traditional soldering. There’s less oxidation, less cleanup, and no discoloration of surrounding areas.
  • Ideal for Repairs
    Laser welding shines when repairing broken chains, resizing rings, or re-tipping prongs. Its low-impact precision allows us to restore delicate heirloom jewelry without damaging its character. Learn more about our custom jewelry services.
  • Versatile Across Metals
    From platinum and gold to titanium and even mixed metals, laser welding is compatible with a wide range of materials used in modern fine jewelry.

Fringe Detail Work Made Easy

Laser soldered gold heart jewelry with fringe by R&M Fine Inc

Each gold fringe element was laser soldered using our Orion laser welder. The small jump rings connecting the heart and fringe are in hard-to-reach areas where traditional torch soldering could cause heat damage or visible solder clumps. Laser soldering ensures clean seams with no excess buildup.

Precision in Two-Tone & Organic Jewelry Designs

Laser soldering is especially valuable in two-tone settings and non-traditional designs, where conventional torch techniques often fall short due to the complexity of the metalwork or risk of overheating nearby components.

The example below shows a custom engagement ring with a yellow gold shank and a white gold pear-shaped diamond setting. This piece was finished using our Orion laser welder, which allowed us to bond the two metals seamlessly without affecting the polish, diamond, or structural integrity.

Before & After: Setting Detached and Laser-Welded to Shank

Detached pear-shaped diamond setting before laser welding by R&M Fine Inc

The white gold pear-shaped setting was crafted separately and prepared for attachment to the yellow gold shank. Traditional soldering here could risk damaging the setting or stone. Laser soldered two-tone ring with diamond setting by R&M Fine Inc

Laser soldering allowed us to precisely join the two components with clean, invisible seams and no visible solder clumps — essential for maintaining the elegance of the design.

Why Laser Welding Is Often the Only Option

  • Extreme control: Heat is applied only to the joint area, protecting sensitive materials like diamonds and enamel.
  • No visible solder marks: Ideal for high-polish and designer pieces where appearance is everything.
  • Supports non-linear, organic design: Uniquely shaped elements can be joined without compromising geometry or flow.

Final Thoughts

Laser soldering has truly revolutionized the way we approach both jewelry manufacturing and repairs. It allows for faster production, reduced risk of damage, and exceptional craftsmanship — all of which benefit both our clients and their end customers.

If you’re a jewelry designer looking for a manufacturing partner that embraces innovation without compromising on quality, contact us today or visit our Jewelry CAD & Printing page to learn more.