Small-part finishing for factories in Lat Krabang Industrial Estate
Lat Krabang is where Bangkok makes small, precise things. On parts that size the coating is no longer a finish on top of the part — it is a share of the tolerance, and it has to be budgeted like one.
We run one plant, and it is in Samut Sakhon. This page covers collection and delivery for customers in Bangkok — it is not a branch or a facility in Bangkok.
This estate at a glance
| Province | Bangkok |
|---|---|
| Road corridor | — |
| Nearest sea port | Bangkok Port (Khlong Toei) |
| IEAT-designated | Yes |
| Eastern Economic Corridor | No |
| Industry mix | electronics, automotive & parts, general manufacturing & SMEs |
IEAT-designated covers both estates operated by the Industrial Estate Authority of Thailand and joint-operation estates run with a private developer. A dash means we could not confirm a single status for the whole area — some of these names describe a factory district rather than one designated estate.
A dash in the port row means the estate sits inland between two ports and we will not guess which is nearer. Nothing on this page is a distance, a drive time or a delivery-time promise.
Reviewed:
What this estate is
Lat Krabang is an estate the Industrial Estate Authority of Thailand operates itself rather than with a private developer, on the eastern edge of Bangkok, addressed off Chalong Krung Road. Its own record puts industry-related services first, then automotive and transport, then electrical appliances, electronics and scientific instruments — an unusual mix for an estate inside a capital city, and the reason the parts that come out of it skew small. A screw from Lat Krabang is more often an M3 or an M4 than an M12, and it is more often judged on how it looks and how it threads than on how hard it is.
What this estate asks of a small part
Small diameters change which numbers matter. A zinc layer that is unremarkable on an M12 bolt is a meaningful fraction of the pitch on an M3 screw, so the thread has to be cut or rolled to a class that leaves room for it and the ISO 4042 thickness has to be chosen against that room, not against a house default. Below that, three things recur: appearance, because these parts are visible in an assembly; cleanliness, because they go into equipment that will not tolerate loose particles; and hexavalent-free chemistry, because the restricted-substance lists that govern electronics assemblies say so — which is why every zinc line here is Cr3+ passivated. What we do not run is contact plating. Tin, nickel and silver on connector pins are a different supplier’s trade, and we would rather name that at quotation than take in a lot we cannot finish.
Services for factories in this estate
Hardening, Cr3+ zinc plating, phosphate coating and in-house lab testing, all on small parts at bulk volume.
Steel grades behind those parts
End markets on this estate
Each end market has its own spec drivers — property classes, salt-spray hours, governing standards.
The corridor row on this page is blank on purpose: the estate is addressed off Chalong Krung Road, and that is not one of the eight highways this table names — we would rather leave the row empty than fit the estate to a road it does not front. The nearest sea port by geography is Bangkok Port at Khlong Toei. Worth knowing, though, that nearest and actual are not the same thing here: the Lat Krabang inland container depot sits in the same district and is rail-connected to the deep-sea terminals down the coast, so a box packed in this estate often leaves the country through a port that is not the nearest one. Collection and delivery are arranged per lot with sales; we do not publish transit times.
Questions we get from this estate
We use M3 and M4 screws. How much does zinc plating add to the thread?+
Enough that it has to be planned rather than discovered. Plating builds on both flanks, so the effective pitch diameter grows by roughly four times the thickness on the radius, and on a fine pitch that consumes a real share of the tolerance. The usual answer is to hold the thread to 6g before plating and pick the ISO 4042 thickness class against the space that leaves. Send the thread class and the coating class together and we will tell you whether they fit each other before anything is run.
Our customer’s restricted-substance list bans hexavalent chromium. Is your zinc compliant?+
Our zinc plating is finished with trivalent-chromium (Cr3+) passivation, so there is no hexavalent chromium in the passivate. Send us the specification number your customer imposes and we will confirm against that document rather than against a general statement, and the passivate type is recorded on the lot.
Can you tin-plate or nickel-plate connector pins for us?+
No. We run heat treatment, zinc plating with Cr3+ passivation, phosphate coating and black oxide. Tin, nickel and silver contact plating is a separate trade with separate baths and separate testing, and it is not something we do. If that is what the part needs, we will say so at quotation instead of taking the work and improvising.