How It Works
From drawing to delivery — transparent at every step
How to work with us
Send your drawing or sample
Share a photo, drawing or sample with the material, quantity and spec you need.
Send the steel grade, the hardness or property class (8.8, 10.9, 12.9), the effective case depth if the part is case-hardened, and the coating and salt-spray class you have to meet.
Get a quote within 24 hours
Our engineers assess the right process and send a quote back within one business day.
The route follows from the grade and the class: carburizing at 880–950°C, carbonitriding at 820–880°C, or neutral hardening at 800–870°C — each of them followed by tempering.
Approve a sample lot
We run a trial lot to confirm hardness and coating thickness before full production.
The trial lot is measured against whichever limits the drawing sets — surface hardness to ISO 6507 (HV) or ISO 6508 (HRC), effective case depth to ISO 2639, coating thickness by XRF to ISO 3497 — before the recipe is fixed for volume.
Production with quality control
We produce to ISO 9001:2015, with in-house lab inspection on every lot.
Every lot then runs to that fixed recipe: austenitizing band, oil quench, and tempering as a separate stage at 150–650°C, with lab checks on the lot in our own laboratory.
Delivery with a test report
Shipped with a test report, ready for ongoing repeat orders.
The report carries the job and lot number, the material and specification, the test method and instrument, the measured values against the acceptance limits, and the date, inspector and approval.
What happens inside steps 3 and 4
The five steps above are how a job moves. This is what the furnace line does to the part: the route chosen from your drawing, the band it is held at, and the tempering stage that follows every quench.
Carburizing
880–950°C
Hard, wear-resistant surface case (typ. 0.1–1.0 mm effective) over a tough core.
CompareNeutral / through-hardening
800–870°C
Full-section hardening of thin fasteners, then tempering to the target class.
CompareStress-relief tempering
150–400°C
Low-temperature tempering to relieve stress and reduce brittleness.
CompareWhat every hardened lot passes through, in order
- 1
Incoming check and clean
Parts are counted in against the job number and degreased. Oil, scale and drawing lubricant left on the surface stop the quenchant wetting bare steel — that is what a soft spot is made of.
- 2
Austenitizing
Held in the mesh-belt furnace at the band for the route — carburizing 880–950°C, carbonitriding 820–880°C, neutral hardening 800–870°C — long enough for the whole load to reach temperature, not just the top of it.
- 3
Quench
Quenched into oil. The medium, its temperature and its agitation are part of the recipe rather than a detail around it: they set the cooling curve, and a quench oil left to drift comes back as scattered hardness in the next lot.
- 4
Tempering — always a separate stage
Reheated at 150–650°C for the class required; stress relief runs lower, at 150–400°C. ISO 898-1 sets a minimum tempering temperature — 425°C for class 10.9, 380°C for 12.9 — and tempering below it to reach a hardness number is how a lot passes the hardness check and fails in service.
- 5
Plating, baking and release
If the part is electroplated, anything at or above 320 HV (classes 10.9 and 12.9) is baked at 200–230°C, started within 1–4 hours of plating and before chromating, to ISO 4042. The lot is then measured against the drawing and released with its report.
Bands are typical and are confirmed against the actual part, drawing or governing standard before the first lot runs. Effective case depth is set by your drawing.
View evidence and report formatBuilt to handle your volume
2,000 tons / month
High-volume capacity for small parts — screws, nuts, bolts and springs.
Quote within 24 hours
Send a drawing today, know the price by the next business day.
ISO 9001:2015 certified
Quality controlled at every step, inspected in our own lab.
Why manufacturers switch to VSheat
Specialised in small parts
Focused on high-volume screws, nuts, bolts and springs — not large parts.
Everything under one roof
Heat treatment + Cr3+ zinc + phosphate + lab testing in one plant — fewer hand-offs.
Sample before full production
Confirm the spec with a trial lot to de-risk before a large order.
Multilingual team
Thai and international customers — contact us and get a quote in your language.
Ready to get started?
Send your drawing or a part photo and get a quote within 24 hours.