BTHC-0005 is our house-formulated HVAF cermet coating, built to do the job hard chrome plating used to do — only without the hex-chrome tank behind it.

The short version: we spray a tungsten-carbide-based powder at very high velocity and relatively low flame temperature, which lays down a dense, tough layer that bonds tightly to your part. Compared to hard chrome, it shrugs off abrasion better in ASTM G65 testing, runs past 1,000 hours in salt spray where chrome plate typically fades around 150, and holds up to about 932°F service temperature. It's also more ductile, so it's less prone to the fine crack network that lets corrosion creep under chrome.

Where it fits: hydraulic rods, pump components, print rolls, oil & gas valves, landing gear — anywhere a ground, polished, wear-hard surface earns its keep. Where it doesn't: anything with an inside diameter under about 4 inches, or builds thinner than roughly 0.004". We'll tell you straight if your part is one of those — chrome still has a place.

The exact recipe is proprietary, but the physics and the regulatory math aren't.

Send us the part — we'll tell you if it's a fit.

BTHC-0005 — download the spec sheet (PDF) ↗

Technical data

Hardness: N/A — proprietary (typical HVAF WC-CoCr: 1200-1400 HV, up to 1500-1700 HV with fine powder)
Bond strength: N/A — proprietary (typical HVAF WC-based: >12,000 psi, exceeding ASTM C633 glue-pull limits)
Max service temp: up to ~932°F
Max service temp: up to ~500°C
As-sprayed porosity: N/A — proprietary (typical HVAF WC-based: <1%, often <0.5%)
Typical thickness: 4-50 (0.004"-0.050")
Surface finish (Ra): Better than 1 Ra-in achievable; typical post-grind 4-8 Ra-in

Where it earns its keep

No hexavalent chromium — sidesteps OSHA Cr(VI) PEL (5 µg/m³), EPA NESHAP 40 CFR 63 Subpart N, and EU REACH Annex XIV exposure for your supply chain
Outwears hard chrome in ASTM G65 abrasion testing with less volume loss, and clears 1000-hour salt-spray vs. roughly 150 hours for chrome
Denser, tougher coating — HVAF's lower flame temperature (~1,950°C vs. HVOF's 3,000°C+) preserves carbide structure and cuts porosity below 1%
More ductile than electroplated chrome — resists the microcrack network that lets corrosives reach the base metal
Depositable up to 0.050" thick in a single setup; polishable to better than 1 Ra-in without hand lapping

Where it doesn't

Line-of-sight process — not a fit for inside diameters under about 4 inches or deep blind bores; hard chrome still wins that geometry
Minimum practical thickness runs ~0.004-0.005", so thin-build decorative or dimensional-restoration work under that floor isn't a good match
Post-spray grinding with diamond wheels is almost always required to hit final dimension and finish — factor that into lead time and cost

Regulatory context

OSHA 29 CFR 1910.1026 — hexavalent chromium PEL of 5 µg/m³ (8-hr TWA), action level 2.5 µg/m³
EPA 40 CFR Part 63 Subpart N — NESHAP for chromium electroplating; PFOS fume-suppressant ban effective 2015
EU REACH Annex XIV — chromium trioxide sunset date September 21, 2017; ECHA Annex XV restriction dossier advancing 2026-2027
ECJ ruling C-144/21 (April 2023) partially annulled the 2020 Commission authorization for chromium trioxide uses
Aerospace + defense OEM specs increasingly require Cr(VI)-free surface treatments in new-build and overhaul

Notes

Hard-chrome plating alternative.

Sources

Data points on this page draw on the following published references. Nothing here replaces a material-specific review by our process engineers — but it's the working starting point.

HTS Coatings — BTHC-0005
“Specially formulated cermet alloy designed as a hard-chrome alternative; up to 0.050" thick; polishable to better than 1 Ra-in; functions up to 932°F.”
HVAF Thermal Spray vs. Hard Chrome Plating
“BTHC-0005 passes the 1,000-hour salt-spray test; hard chrome plating passes about 150 hours. BTHC-0005 has less volume loss than hard chrome under ASTM G65.”
Kermetico — WC-CoCr HVAF Properties
“Hardness typically 1200-1400 HV with HVAF; bond strength >12,000 psi; porosity <1%.”
OSHA — Chromium (VI) Standard
“PEL of 5 µg/m³ as an 8-hour TWA; action level 2.5 µg/m³.”
ECHA — Cr(VI) Restriction Proposal
“Chromium trioxide sunset under Annex XIV effective September 21, 2017; broader Cr(VI) restriction advancing 2026-2027.”

Material data on this page is provided as a general reference and can vary by lot, substrate, and application. Contact HTS to confirm the right material and specification for your specific part.

BTHC-0005

Technical data

Where it earns its keep

Where it doesn't

Typical applications

Wear modes addressed

Industries

Substrates

Regulatory context

Notes

Sources

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