V.S. Heat Treatment
Heat treatment & metal finishing experts
Heating up
V.S. Heat Treatment
Heat treatment & metal finishing experts
High-volume heat treatment of screws, nuts, bolts, washers and small fasteners on continuous mesh-belt furnaces — plus eco-safe Cr3+ zinc plating, phosphate coating and an in-house testing lab, delivered on time to international standards.
0+
Years of experience
EST 1994
ISO
9001:2015
CERTIFIED
0+
tons / month
CAPACITY
Heat Treatment
Small-parts heat treatment service · 2,000+ tons/month
Zinc Plating Cr3+
Cr3+ zinc plating service · RoHS-safe
Phosphate Coating
Paint base layer and friction reduction
Testing Laboratory
Precise inspection and certification
We adapt processes to your part — from one-off prototypes to high-volume production.
Continuous mesh-belt furnaces deliver consistent quality on schedule and reduce your cost.
Every batch is tested with Vickers and X-ray instruments and shipped with a quality certificate.
Recently updated pages and the decisions engineering, purchasing and QC teams make in real work.
Compare S45C and SCM440 carbon, hardenability, HRC ranges, toughness, section-size effects and the information needed on a heat-treatment order.
Read the answerBuild a salt-spray test request with method, duration, inspection interval, specimen count, corrosion criteria and reporting. Copy or save it for RFQ and QC.
Read the answerA practical comparison of common hardening steels—S45C, SCM435, SCM440, SK5, SUP9—showing the hardness each can reach and which fasteners they suit.
Read the answerRead hardness values with confidence: understand Rockwell, Vickers and Brinell and pick the right scale.
Read the answerThe colour of zinc plating comes from the chromate passivation layer on top—it is not just looks; it also signals corrosion resistance. Here is the chart.
Read the answerThe salt-fog corrosion test: what the “hours” number means and how much to trust it.
Read the answerWhat the gray-black phosphate surface is for, how it differs from zinc plating, and choosing zinc vs manganese.
Read the answerEffective versus total case depth, the 550 HV hardness traverse, and the transition from legacy ISO 2639 to current ISO 18203:2026—with an unambiguous callout example.
Read the answerPlating and testing — all under one roof
Trusted by manufacturers across Thailand and beyond
Automotive
Fasteners / Bolts & Nuts
Construction
Industrial Machinery
Agricultural Machinery
Electronics
Japanese, Chinese, Taiwanese and Korean manufacturers choose V.S. Heat Treatment — supported in their own language and export-ready.
Full support in 日本語 / 中文 / 한국어 / English — quotation, certificates and engineering advice.
Cr3+ (Cr6-free) plating with RoHS / REACH documentation for EU and Japanese supply chains.
ISO 9001:2015 with lab testing on every lot — meets automotive and electronics maker specs.
We collect and deliver across Amata, WHA, Bang Poo, Laem Chabang, Rojana, Navanakorn and more.
We migrated entirely to RoHS-compliant Cr3+ in 2020. Here's why it matters.
Cr6+
Hexavalent · Legacy
Cr3+
Trivalent · Eco-safe
✓ V.S. Heat Treatment uses Cr3+ exclusively since 2020
Browse by service area, industrial estate, part type or finish — or dive into our metallurgy knowledge base.
Our engineers reply with a tailored quote within 24 hours.
Insights on metallurgy and surface treatment from our team
Pricing depends on material, part size, quantity and certification needs. Send us a photo and details — we'll quote within 24 hours. Or use the Quote Calculator for a quick estimate range.
Cr3+ (Trivalent Chromium) zinc plating uses chromium-3 ions, which are non-carcinogenic and meet RoHS/REACH directives. It replaces the older, hazardous Cr6+ (Hexavalent). We migrated entirely to Cr3+ in 2020.
Per ASTM B117: Cr3+ Blue passivation reaches 96 hours, Yellow 144 h, Black up to 240 h. We can engineer specs to exceed 280 h on demand.
Carbon steel (S45C, SCM440), alloy steel (SKD11, H13), stainless (SUS304, 316), and other materials by agreement. Send specs to our team for review first.
Yes — Hardness Test Report (HV/HRC), Coating Thickness Report (X-ray), Salt Spray Test Report (ASTM B117), Material Test Certificate. Issued with the order or separately.
Flexible — from a few prototype pieces to mass production of tens of thousands per month.
