Your heat-treatment & fastener-finishing supplier in Thailand
A single Samut Sakhon factory for hardening, Cr3+ zinc plating, phosphate and in-house testing of small fasteners — built for OEM and export buyers.
Sourcing fastener heat treatment or plating from Thailand?
V.S. Heat Treatment is an ISO 9001:2015 factory in Samut Sakhon, Thailand, that hardens and plates small fasteners — screws, nuts, bolts, washers and pins — on a continuous mesh-belt line, above 2,000 tons per month. Cr3+ zinc plating is Cr6-free and EU-export ready, every lot ships with a test certificate, pricing is per kg or ton, and we reply to quotes within 24 hours.
- ISO 9001:2015 (SGS)
- Cr6-free · RoHS / REACH
- EN 10204 3.1 MTC per lot
- In-house lab
- Third-party inspection welcome
- 2,000+ t
- per month
- 1994
- established
- ISO 9001
- 2015 (SGS)
- 24 h
- quote reply
Why source from us
ISO 9001:2015
Certified quality management (SGS Thailand). Consistent, auditable process control lot to lot.
Cr6-free, EU-ready
Cr3+ (trivalent) zinc plating — RoHS/REACH compliant and free of hexavalent chromium for EU and automotive supply chains.
Full export documentation
RoHS / REACH declarations, material and test certificates, and coating-thickness / hardness reports on request.
2,000+ tons per month
Continuous mesh-belt furnace for high-volume small parts, from prototype quantities to mass production.
In-house laboratory
Vickers (HV) hardness, X-ray coating thickness and salt-spray testing — a certificate with every lot, no external lab.
Priced per kg — quote in 24h
Transparent per-kilogram / per-ton pricing (not per piece), with a quotation reply within 24 hours.
What we process
We specialise in small fasteners and hardware in bulk — not large gears, shafts or mould inserts. If it runs on a continuous mesh-belt furnace, it is our core work.
- Parts
- Screws, nuts, bolts, washers, pins, rivets and small hardware (typically M4–M16).
- Materials
- Carbon steel (S45C, SWCH), alloy steel (SCM435, SCM440), boron steel, spring and stainless grades.
- Services & finishes
- Hardening (carburizing / carbonitriding / quench & temper), Cr3+ zinc plating (white / blue / yellow), Mn-Zn phosphate, black oxide, hydrogen de-embrittlement baking, and lab testing.
Capability & typical results
| Process / finish | Typical result | Standard |
|---|---|---|
| Case hardening (carburize / carbonitride) | Surface 550–750 HV, case 0.1–0.3 mm | ISO 2639 / drawing |
| Through hardening (quench & temper) | Per class 8.8–12.9 (≈22–44 HRC) | ISO 898-1 |
| Cr3+ zinc plating (white/blue/yellow) | 5–12 µm, ≈72–200 h salt spray | ASTM B633 / ISO 2081 / ISO 9227 |
| Mn-Zn phosphate | Coating weight to spec + oil seal | DIN 50942 / ISO 9717 |
| Hydrogen de-embrittlement baking | 200–230°C within ≈1–4 h of plating | ISO 4042 |
| In-house lab testing | Vickers HV, XRF thickness, salt spray | ISO 6507 / ISO 3497 / ISO 9227 |
| Documentation | MTC per lot (EN 10204 3.1), RoHS/REACH | EN 10204 / RoHS / REACH |
Typical achievable ranges for small fasteners — confirmed against your part and the governing standard, not guarantees.
How to order from overseas
Sourcing from abroad is straightforward — send the spec, we quote, you ship the parts in.
- 1Send your drawing, material grade and target hardness / finish (a sample photo helps).
- 2We review and reply with a per-kg / per-ton quotation within 24 hours.
- 3Ship parts to our Samut Sakhon factory (we can advise on freight and customs contacts).
- 4We process, run hydrogen de-embrittlement baking where required, and test every lot.
- 5You receive the finished parts with a test certificate and the export documents you need.
Export markets & compliance
We serve OEM and distribution buyers across ASEAN, China and Europe with full compliance documentation.
- Cr3+ zinc plating is Cr6-free — ready for EU and automotive (ELV) supply chains.
- RoHS and REACH declarations available for every plated finish.
- Material, hardness and coating-thickness certificates supplied per lot.
- Flexible minimum order — from prototype runs to mass production.
Compliance by market
| Market | What we meet | Documents supplied |
|---|---|---|
| EU | Cr6-free Cr3+, RoHS, REACH SVHC, ELV Annex II | RoHS & REACH decl, MTC (EN 10204 3.1) |
| USA | ASTM B633 / F1941 zinc classes | MTC, coating-thickness & salt-spray report |
| Japan / Korea | JIS/KS grade equivalence, Cr6-free | MTC, RoHS declaration |
| Automotive | ELV-ready Cr3+, ISO 4042 baking | IMDS data on request, MTC |
| ASEAN | ISO 9001:2015 process control | Test certificate per lot |
Shipping, logistics & customs
- Ship parts to our Samut Sakhon factory via Laem Chabang / Bangkok (Klong Toey) seaports or Suvarnabhumi (BKK) airport — all within easy reach.
- We work on your Incoterms (e.g. EXW / FCA / DDP-in); your forwarder handles customs. We can advise on freight and customs contacts.
- We process customer-supplied (free-issue) parts and return them packed on pallets or cartons with VCI as required.
- Heat-treated / plated steel fasteners typically fall under HS heading 7318; RoHS/REACH and material/test certificates accompany the return shipment for customs.
- Independent third-party inspection (SGS, Bureau Veritas, Intertek) or a factory audit is welcome on request.
Sourcing FAQ
Do you export / work with foreign buyers?
Yes. We process customer-supplied parts and provide RoHS/REACH and test documentation for export to ASEAN, China and Europe. Pricing is per kg or ton and quotes are returned within 24 hours.
What is the minimum order?
The minimum order is flexible — from a few prototype pieces to full mass production. Tell us the part, material and quantity and we will quote it.
Is your zinc plating Cr6-free / RoHS compliant?
Yes. We use Cr3+ (trivalent chromium) zinc plating, which is free of hexavalent chromium and RoHS/REACH compliant — suitable for EU and automotive supply chains. RoHS/REACH declarations are available.
Do you handle hydrogen de-embrittlement baking?
Yes, in-house. High-strength parts (class 10.9 and above) that are electroplated are baked to relieve hydrogen embrittlement per ISO 4042, with logged time and temperature.
How do I get a quotation?
Send your drawing or a photo, the material grade and the target hardness or finish. We reply with a per-kg / per-ton quotation within 24 hours.
Send us your spec — quote within 24 hours
- ISO 9001:2015 (SGS)
- Cr6-free · RoHS / REACH
- EN 10204 3.1 MTC per lot
- In-house lab
- Third-party inspection welcome