A buyer sends back a reorder of silver bangles because half the soldered joints have darkened to a dull gray and a few have opened. The repair house used easy-flow solder for every joint — the easiest grade to melt — and the second time the piece hit heat during polishing or plating, the easy solder ran again. Silver solders are graded by flow temperature, and choosing the wrong grade on a multi-joint piece is the single most common soldering error we see. Here is how we pick on the bench.
The three grades and their melt ranges
Jewelry silver solder comes in four grades, but three get used daily. Hard solder flows around 740–780 °C (1365–1435 °F), medium around 700–730 °C, and easy around 690–710 °C. The gap between grades is small — only 30–50 °C — but it is enough to let you solder a second joint without re-melting the first. Sterling silver itself melts near 890 °C, so all three solders flow well below the parent metal. The alloy basis for 925 is set out in the sterling silver reference on Wikipedia.
Why we start every piece on hard
The first joint on any assembly gets hard solder. If a ring shank has a bezel and a shoulder seam, the bezel goes on with hard, then the shoulder seam with medium, then any repair touch-up with easy. Working this way, each new joint flows at a lower temperature than the one already in place, so the earlier joints do not let go. A shop that starts with easy has no lower-temperature option left and ends up with every joint opening on the next torch pass. Common joint failures we inherit are listed in jewelry soldering common joints and risks.
Color, strength, and finish
Hard solder on 925 is closest in color to the parent metal because it contains the least zinc (zinc is what lowers melt temperature and darkens the seam). Easy solder carries more zinc, so the seam often grays and may need extra pickling and polish to blend. Strength follows the same order: hard is strongest, easy is the softest. On a ring shank that will be sized later, we avoid easy solder because the next sizing cut will hit a soft seam. Nickel-free requirements for the finished piece are covered in nickel-free silver alloy under EU REACH, and a repair that needs a remake instead of a weld is discussed in ring shank repair: weld vs remake.
When easy is the right call
Easy solder is not a shortcut — it has one correct job. It is for final touch-ups on pieces that already have hard and medium joints in place, and for soldering heat-sensitive parts (like a stone already set) where we want the shortest possible heat cycle. On a purely structural joint on a new piece, easy is the wrong grade. Porosity that can result from overheating near a seam is diagnosed in 925 silver casting porosity defects.
Wire, sheet, and paste forms
The same solder comes in three forms, and the form changes how clean the joint looks. Wire solder is the default for a clean butt joint on a shank: a 1 mm chip placed at the seam flows where you put it. Sheet solder cut into 2 mm squares is used for small parts like posts on earrings, where a blob of wire would run onto the stone seat. Paste solder — solder powder mixed with flux — is used for mass-produced findings and for heat-sensitive jobs because you can dot it on with a syringe and avoid holding the flame in one spot. We keep all three on the bench, but on structural jewelry we default to wire because paste solder can leave a flux residue that etches the surface under plating.
Can I use easy solder on a ring size-up?
No. A sizing joint takes pulling force and needs hard or at minimum medium. Easy will open after a few months of wear.
Does solder color matter for rhodium plating?
Yes. Easy-solder seams can etch differently in the electro-clean step and show as a faint line under rhodium. We use hard on anything destined for plating.
How do I tell which grade was used?
By testing with a hot tip: touch a hard solder wire near a joint. If the joint flows before the test wire, the joint is easy or medium. Most buyers rely on their factory to log the grade on the traveler.
Is gold solder graded the same way?
Yes — hard, medium, easy — but the flow temperatures track the karat. 14k hard solder flows around 780–830 °C, lower-karat solders run cooler.
Tell us your joint order and we will spec the right solder grade. HOLYCOME assembles, solders, and finishes silver and gold jewelry in-house — ask about our custom manufacturing program and send your assembly drawing, and we will return a solder schedule and joint-by-joint heat plan.
Frequently Asked Questions
How do I prevent sterling silver from tarnishing in storage?
Use anti-tarnish bags with a sulfur absorber, keep humidity under 60% and avoid paper wrapping. Rhodium plating adds a further barrier on high-turn SKUs.
Is rhodium plating worth the added cost?
Yes for display and gift lines. It resists tarnish for 12–18 months and keeps shelf pieces bright, which reduces markdowns.
What purity do you supply?
925 sterling silver, stamped and hallmarked. Fine silver (.999) is available for beads and bullion-style pieces.
What is the MOQ and lead time?
50 pieces per design, samples 3–5 days, bulk 15–20 days.
