Stannous sulfate, also called tin(II) sulfate, is a white to off-white crystalline solid supplied as an AR Grade raw material for acid tin baths. It is a salt for bath make-up, not a pre-mixed brightener or a complete plating solution.
The material acts as a stannous ion source. After dissolution and bath preparation, it provides Sn²⁺ for tin deposition on steel, copper and other suitable substrates. Tin coatings are used where solderability, corrosion protection and a controlled surface finish are required.
This grade is produced to GB/T 23839-2009 with a stated content of ≥99%. Buyers working in industrial tin electroplating use it when they want to weigh the solid, dissolve it into their own formulation and set the tin-ion concentration their line requires.
As a plating material, it is handled in the same way as other solid bath salts: check the batch details, weigh the required amount, dissolve completely and add according to the process sheet.
| Product | Stannous Sulfate |
| Chemical Name | Stannous Sulfate, Tin(II) sulfate |
| CAS No. | 7488-55-3 |
| Molecular Formula | SnSO4 |
| Molecular Weight | 214.77 |
| Content | ≥99% |
| Product Grade | AR Grade |
| Standard | GB/T23839-2009 |
| Physical Form | White to off-white crystalline powder (solid) |
| Net Weight | 25 kg/package |
| Application | Raw material for industrial tin plating |
| Inspect Items | Specification |
| Assay (SnSO4), % | ≥99.0 |
| Fe, % | ≤0.005 |
| HCl insoluble material, % | ≤0.005 |
| Pb, % | ≤0.02 |
| Alkali metal and alkaline earth material, % | ≤0.10 |
Fengfan stannous sulfate is a solid electroplating raw material supplied for acid tin and tin-alloy bath preparation. The product is a white to off-white crystalline powder with a content of ≥99%, produced to GB/T 23839-2009 in AR Grade. Its main role is to provide stannous ions after it has been dissolved and added according to the process formulation.
High-Purity Solid Electroplating Raw Material
The crystalline solid is intended for weighing, dissolution and controlled addition during bath make-up. It is not a pre-mixed brightener or a complete bath, so the formulator keeps control of the full chemistry, including the stannous sulfate addition rate and the other bath components.
Controlled Purity for Stable Bath Preparation
The inspection specification sets Assay (SnSO4) at ≥99.0%, Fe at ≤0.005%, HCl insoluble material at ≤0.005%, Pb at ≤0.02%, and alkali metal and alkaline earth material at ≤0.10%. These limits provide a defined quality basis for bath preparation and replenishment. They do not replace your own process validation, because the final deposit depends on the entire bath, operating conditions and post-treatment.
High-Purity Stannous Ion Source
After dissolution, the material provides Sn²⁺ for tin deposition. Consistent assay and controlled impurities help reduce the risk of impurity-related defects and support repeatable preparation or replenishment of acid tin and tin-alloy baths.
The grade is listed with its CAS number, molecular formula and inspection limits so buyers can compare it with other electroplating materials used in their bath calculations.
Keep the product sealed in a dry, ventilated place and protect it from moisture. Use suitable gloves, eye protection and dust control during handling. Avoid opening packages in damp conditions or leaving the solid exposed, because moisture uptake can change how the material weighs out and dissolves. Use clean, dedicated scoops and containers to reduce cross-contamination with other bath chemicals. The technical datasheet and MSDS are available for your safety review, and staff who handle the solid should be briefed on dust control and local site rules. If a package is damaged or has been stored in humid conditions, check the material before use and contact your supplier for advice.
Fengfan supplies industrial chemical raw materials to customers in China and overseas markets, with support for product selection and technical documentation. For this grade, product datasheets and MSDS documents are available to support storage, handling and preparation reviews.
If your team is comparing this tin salt with other electroplating materials, share your bath system, substrate and target finish, and we will answer on the points covered by the product data.
The addition rate itself should be confirmed through your own bath formulation and process validation; we do not set a single universal dosage because the full bath chemistry governs the result.
We also support industrial electroplating customers with the document set needed for incoming-goods review. Ask our team for the current datasheet and MSDS for your files.
The product is supplied as a raw material for plating lines, not as a turnkey bath package. That keeps the formulation work with your process team while we focus on the grade, documentation and supply.
Stannous sulfate is used as a raw material for preparing or replenishing acid tin baths. After proper dissolution, it supplies stannous ions for tin deposition on suitable steel and copper substrates. Depending on the full bath formulation, tin deposits can support solderability, corrosion protection and a bright or matte surface finish. The product itself is a stannous sulfate raw material, not a complete plating bath.
For tin plating on copper, confirm the pre-treatment, bath chemistry and operating window before production; the salt is only one input in the process.
Within a metal plating process, addition rate should follow your own formulation and be checked against bath analysis. For a line that already runs an acid tin bath, compare the assay and impurity limits in the specification with your current certificate before changing source.
Tin coatings are used on connectors, terminals, PCB surfaces and electronic components where solderability and oxidation resistance are important. Fengfan stannous sulfate can serve as the stannous sulfate raw material in suitable acid tin processes. Final use depends on the plating chemistry, operating conditions and post-treatment process. Customers should evaluate the product in their own production line before large-scale use. For a PCB or component finishing line, confirm that the bath is an acid tin system compatible with a stannous sulfate source, and check the impurity limits against your own end-use requirements.
Choosing the right match is where most sourcing decisions stall. As a trading supplier, we keep one point of contact from first enquiry to after-sales: tell us what you are making and the conditions you work under, and we shortlist the closest matches from our supplier network, compare specifications and arrange samples before you commit to a bulk order. If something does not behave as expected, we work with the supplying partner on the cause and a practical fix, and stay with the case until it is settled. Email, WeChat or WhatsApp enquiries get a reply within 24 hours.
Fengfan stannous sulfate is a dry crystalline salt, so what arrives is a solid you weigh and dissolve rather than a drum of ready-mixed electrolyte. In practice the material is scooped from its container, weighed on a balance suited to the addition size, and dissolved in the make-up water or directly in the bath before it is expected to do any work. Dissolve it fully and stir until the liquor is clear, because crystals sitting on the tank bottom contribute nothing to the stannous ion content and can leave you with a false picture of where the bath actually stands. Use a clean, dry, dedicated scoop — a damp one will cake the surface of the stock and make the next weighing inconsistent. Because the solid carries no water, brightener or antioxidant, everything else in the bath stays under your control. Where a line prefers liquid handling, the salt is dissolved in-house to your own concentration rather than bought pre-dissolved.
It is dissolved and added according to the bath formulation, where it supplies stannous ions for acid tin and tin-alloy systems. The addition rate is set by your own bath recipe and confirmed by bath analysis.
Keep the container closed between weighings. A plating shop is a humid place, and an open drum or bag will pull moisture, cake at the surface and turn a free-flowing crystal into lumps that dissolve slowly. Store the material on a pallet rather than directly on the floor, out of direct sunlight, and away from acid, oxidiser and alkali drums — segregation matters more than distance in a busy chemical store. Keep one dry scoop for this salt only, and never tip material that has already been dispensed back into the stock container. Work first in, first out, and write the opening date on the label so older stock goes first. When a delivery arrives, check that the packaging is sound and the contents still free-flowing before you sign for it. Transfer in a ventilated area without raising a dust cloud, sweep spills up dry instead of washing them into a drain, and dispose of residues and empty packaging under your local chemical waste rules.
This is a plating raw material, not a prepared bath. What you receive is the stannous salt alone; the acid, the brightener or leveller package, the wetting agent and any antioxidant are yours to add in the ratios your process sheet sets out. That division of labour is the point — a supplier cannot know your tank volume, your anode area or the deposit thickness you are targeting, so the make-up arithmetic has to happen at your line. Before use the salt is weighed, dissolved and checked by bath analysis: tin metal content, acid concentration and, where relevant, the additives. Those readings, not the appearance of the powder, tell you whether the bath is on specification. Buying the salt on its own also keeps your records clean, because the paperwork covers one defined material rather than a proprietary blend whose composition may shift between deliveries.
Copper is one of the standard substrates for a tin deposit, and the salt supplies the stannous ions once it is dissolved in an acid tin bath. Two things deserve attention when the part is copper. First, copper and tin interdiffuse at the interface and form an intermetallic layer that thickens with time and temperature; that layer is one reason solderability can fall away during long storage, and it is why some processes put a nickel barrier between the copper and the tin. Second, pre-treatment decides adhesion — degrease and activate the copper properly, because a passive or oxidised surface will give poor coverage no matter how well the bath is running. Watch the bath for copper build-up from drag-in or from parts immersed before the current is applied, and confirm the operating window with a trial before a production run. The salt is one input; the process around it does the rest.
They give you a defined specification to compare against your process: assay, Fe, HCl insolubles and Pb, with the remaining impurity limits set out in the specification table. Your own bath validation still decides whether the grade suits the line.
In electronics a tin deposit is chosen for two jobs: a surface that solders reliably and a surface that resists oxidation in storage. Connectors and terminals use it to keep contact resistance low and to stay solderable through assembly, while component leads and terminations rely on it for a consistent joint. On printed circuit boards, tin-bearing finishes appear in some final finish schemes, and there the well-known reliability question is whisker growth — one reason certain specifications call for an alloyed deposit or an underlayer instead of pure tin. Solderability after storage depends on the intermetallic layer, the post-treatment and how the parts are packed, so those belong in your evaluation alongside the electrolyte itself. Small parts are usually run in barrels or on reel-to-reel lines, where current distribution across the load matters as much as the chemistry. Test the actual assemblies before committing a production lot.
It suits lines that run an acid tin or tin-alloy bath and need a defined stannous source they can weigh and dissolve themselves. It is not a general addition to every tank: putting a tin salt into a zinc, nickel or chromium process introduces tin and sulfate where the formulation does not call for them, so match the material to the bath type first. Within the right bath, the same salt serves rack, barrel and continuous lines — the difference lies in how make-up and replenishment are calculated, not in the material. Your deposit specification drives the decision as much as the chemistry does, because thickness, appearance, solderability and corrosion target all come out of the full formulation plus the operating conditions. When a customer brings us an industrial metal plating project, the conversation starts from the process sheet and the bath analysis rather than from the product alone.
In a metal plating process the salt sits at the make-up and replenishment stage, not at the plating stage itself. The sequence runs: pre-treat the part, prepare or top up the bath, plate under set current and temperature, then rinse and apply the post-treatment. Stannous sulfate sets the initial tin concentration at make-up and replaces what drag-out and consumption remove afterwards; where tin anodes are used they carry the steady-state supply, so the two sides have to be balanced from analysis rather than from habit. Replenish on the numbers from your tin metal and acid titrations, not on how the bath looks or how many parts have gone through, and keep a log of additions so drift becomes visible long before a defect appears. Filtration, temperature control and current density complete the picture, and the post-treatment you choose decides how the deposit behaves in service.
This grade is bought by plating shops and formulators who build their own bath chemistry and want a documented tin salt rather than a proprietary blend. That covers job shops running acid tin on steel or copper, manufacturers who tin their own components in-house, and distributors who stock plating chemicals for a regional customer base. If you repack or resell, a dry solid suits warehouse handling better than a liquid concentrate and does not need the same protection from temperature swings in transit. It is not aimed at the buyer who wants one drum that plates straight out of the container; that buyer needs a finished process package, not a raw salt. A practical test of fit is whether you already run a bath analysis routine and hold a process sheet for the tank. If you do, this material slots into controls you already have.
Start at the bench. Request a sample lot and see how it handles on your own bench: dust when transferring, how readily it goes into solution, and whether the crystal suits your dispensing method. Then make up a trial bath to your existing formulation with everything else kept identical, and compare analysis results, deposit appearance, adhesion and coverage on test panels taken from both baths. Keep a retained sample of the outgoing and the incoming material so any later defect can be traced. Plan the changeover for a natural break in production rather than mid-run, and confirm packing, delivery schedule and the paperwork you will receive with each lot before placing the first order.
Compare the assay and impurity limits with the limits you hold for your current source, and check the test methods too — similar limits can come from different procedures. Check the material against your bath formulation, and run your normal bath analysis and deposit checks before changing over.
