Metal-Housing Keyfob
Metal RFID Keyfob
Stainless & Zinc Premium Fob
Quick answer
At BOM level, metal RFID keyfobs use 316L stainless steel, die-cast zinc alloy (ZA-4 / ZA-8) or anodised aluminium (6061 / 7075) as the structural housing around a ferrite-backed HF or LF inlay. The metal body delivers 15-30 g hand-feel, a hard-wearing finish, and a chemistry profile that passes EN 1811 nickel-release (≤ 0.5 µg/cm²/week), REACH Annex XVII heavy-metal and SVHC limits, and LGA / FDA 21 CFR 175 food-contact incidental rules. Target use is executive / residential premium access control, automotive / yacht / hospitality premium credentials, food-plant and lab environments where metal is the only cleanable surface, and NEBS / MIL-STD vibration environments where adhesive-sealed plastic housings do not hold.
- 316L stainless, die-cast zinc alloy or anodised aluminium housing with ferrite-backed inlay — 15-30 g hand-feel, 15-25 year housing life, chip replacement is what drives retirement.
- EN 1811 nickel release ≤ 0.5 µg/cm²/week + REACH Annex XVII entries 27 / 63 cleared + LGA / FDA 21 CFR 175 food-contact incidental on stainless variants — full skin + food-plant compliance envelope covered.
- Anti-metal antenna design + 0.3-0.5 mm ferrite sheet deliver HF tap 0-30 mm and LF tap 0-40 mm through the metal shell — no compromise on PACS integration.
Used in these industries
Deployments where this product is referenced on our industry landing pages.
At a glance
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Form factor
Teardrop / rectangle / rounded-rectangle 30-55 mm × 20-30 mm × 4-8 mm; 15-30 g mass; Ø 4-6 mm key-ring hole. Two-piece construction: metal upper shell + ferrite-backed H...
Alloy options
316L austenitic stainless steel per ASTM A276 — corrosion-resistant, non-magnetic, hygienic, easy to passivate per ASTM A967. Die-cast zinc alloy ZA-4 / ZA-8 — cost-effe...
Next step
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Quote metal RFID keyfobs- Air-interface envelope
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- 13.56 MHz HF — ISO 14443 Type A/B (MIFARE Classic 1K, MIFARE DESFire EV3, NTAG 213/215/216, NTAG 424 DNA, I-CODE SLIX2).
- 125 kHz LF — EM4200 / EM4305 / T5577 / HID-compatible for legacy reader estates.
- Antenna design
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- Ferrite sheet 0.3-0.5 mm thick between inlay and metal lower shell decouples the antenna from the metal boundary.
- Read-range on HF 13.56 MHz tap 0-30 mm (versus 0-50 mm in a non-metal shell); LF 125 kHz tap 0-40 mm with tuned anti-metal inlay.
- Nickel release + skin chemistry
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- EN 1811 nickel-release test: ≤ 0.5 µg/cm²/week for prolonged skin contact (fob on a key-ring in a pocket or handbag).
- 316L stainless passivated per ASTM A967; electroplated zinc alloy with thick Ni-Cr top coat; anodised aluminium with sealed oxide layer.
- REACH + RoHS posture
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- REACH Annex XVII entries 27 (nickel release) and 63 (lead in consumer articles) cleared; SVHC candidate-list screen on every plating chemistry lot.
- RoHS 3 (EU 2015/863) cleared on plating + solder + inlay; CA Prop 65 disclosure for consumer markets.
- Food-contact posture
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- 316L stainless is food-grade per LGA / FDA 21 CFR 175 incidental contact; acceptable in food-plant and commercial-kitchen wash-down environments.
- Plated zinc alloy is not food-grade; aluminium not food-contact unless passivated with food-grade anodising per NSF 51 — pick stainless for food use.
- Mechanical durability
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- IEC 60068-2-32 Ea drop 2.0 m (stainless / zinc); 1.5 m (aluminium); IEC 60068-2-6 vibration 5-500 Hz 5 g RMS 2 h / axis.
- MIL-STD-810G shock Method 516.6 (40 g, 11 ms); NEBS GR-63-CORE Level 3 for data-centre key carriers.
- Finish + decoration
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- Laser engraving (30-50 W fibre) for permanent serial + logo on stainless / aluminium; epoxy-filled enamel on zinc alloy.
- PVD (physical vapour deposition) finishes — gold / rose gold / black — for premium hospitality + automotive SKUs.
- Use-case envelope
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- Premium residential and automotive credentials; yacht-club / executive-parking / VIP-membership access.
- Commercial kitchen / food-plant stainless credentials; lab-bench access; NEBS / MIL-STD vibration environments.
- Operational lifecycle
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- Typical field life 15-25 years under daily carry — the housing outlasts the inlay chip technology (chip-family migration is the usual driver for replacement).
- Retirement: laser-engraved serial is defaced, inlay pulled, chip rendered inoperative per NIST SP 800-88; stainless / zinc / aluminium to WEEE metal stream.
Why some credentials specifically call for a metal housing
- Premium residential buildings, luxury hospitality, yacht clubs and executive parking treat the keyfob as a brand artefact; 15-30 g of brushed stainless or PVD-gold-plated zinc alloy communicates permanence and prestige that ABS cannot match.
- Commercial kitchens, food plants and labs run hot-water and caustic wash-down that degrades ABS welds within 1-2 years; 316L stainless tolerates hot-caustic, peracetic-acid and chlorinated-alkaline chemistry indefinitely.
- NEBS GR-63-CORE Level 3 data-centre / telco-central-office key carriers, and MIL-STD-810G vibration programmes, see mechanical stress that can fatigue adhesive seals on plastic housings; the metal shell with laser-welded seam is the mechanical-integrity answer.
- EN 1811 nickel-release ≤ 0.5 µg/cm²/week is the consumer-skin benchmark for any object on a key-ring; REACH Annex XVII entries 27 (Ni) and 63 (Pb) lock the lower safety boundary.
- The metal shell dramatically extends housing life — 15-25 years versus 5-10 for ABS — so the chip inside becomes the limiting factor, and the keyfob can be rewritten / re-encoded through multiple chip-family migrations.
Stainless vs zinc vs aluminium — picking the alloy
Ultrasonically-welded ABS keyfob
- ABS weld seam relaxes under UV + hot-caustic + vibration within 1-7 years depending on environment.
- Cost-effective but does not pass food-grade incidental-contact rules; not acceptable in commercial kitchens / labs.
- Not cleared for NEBS GR-63-CORE Level 3 mechanical retention on its own.
- 5-10 year typical field life; chip usually outlives the housing.
Metal (316L / zinc / aluminium) keyfob
- Laser-welded or snap-fit metal shell with ferrite-backed inlay — 15-25 year housing life.
- 316L stainless is food-contact incidental per LGA / FDA 21 CFR 175; acceptable in commercial kitchens, labs, pharma ancillary areas.
- Stainless / zinc 2.0 m drop + 5-500 Hz vibration survival; NEBS + MIL-STD mechanical envelopes clear.
- Housing outlasts the chip; same shell can run MIFARE Classic → Plus → DESFire EV3 → NTAG 424 DNA generations.
- 316L stainless steel (ASTM A276) — austenitic, non-magnetic, corrosion-resistant, passivated per ASTM A967; the only food-contact-incidental-grade option; most expensive of the three but unquestioned for premium + food-plant + lab use.
- Die-cast zinc alloy ZA-4 / ZA-8 — excellent fine-detail casting, accepts electroplating + epoxy-filled enamel for complex brand logos; mid-price; not food-grade because plating chemistry is not cleared.
- Anodised aluminium 6061 / 7075 — lightweight (50-60 % of steel), broad anodised colour library, laser-engraved logo; lower cost than stainless; aluminium is not food-contact unless NSF 51 food-grade anodising is specified.
- All three alloys pass EN 1811 nickel release ≤ 0.5 µg/cm²/week; the difference is finish options (PVD on stainless, enamel on zinc, anodised on aluminium), food-grade posture (stainless only) and hand-feel.
- Antenna tuning is identical across the three alloys — the ferrite sheet between the inlay and the metal shell is the decoupling element.
Where metal keyfobs earn their place in the catalogue
- Luxury residential / high-rise / private-club access — brushed 316L stainless or PVD-gold-plated zinc alloy with laser-engraved building mark; paired with MIFARE DESFire EV3 for ISO/IEC 27001-aligned AES-128 PACS.
- Automotive / yacht / aviation executive access — dealership loaner fob, service-department credential, yacht-club card alternative; PVD finish matches brand identity; NTAG 424 DNA SUN tap for mobile-wallet integration.
- Commercial kitchens / food plants / labs — 316L stainless credentials cleared for food-contact incidental under LGA / FDA 21 CFR 175; NSF 51 food-grade anodised aluminium acceptable for ancillary use.
- Pharmaceutical / biotech lab / cleanroom ancillary — 316L stainless is the only non-shedding, caustic-resistant credential surface acceptable in grade D / C cleanroom support areas.
- NEBS / MIL-STD hardware-carrier credentials — data-centre hand-off fob, military-GSE credential, rolling-stock operator fob; survives the mechanical-retention envelope that fatigues plastic housings.
- Brand membership / loyalty premium credentials — boutique hotel chain, sports club, premium-brand loyalty programme; PVD finish + NTAG 424 DNA SUN tap-to-reveal for branded content.
How to roll out a metal keyfob programme without breaking PACS or safety chemistry
- Week 1 — alloy + finish selection
Freeze alloy (316L / zinc / aluminium), finish (brushed / PVD / anodised / enamel) and chip per-site; model nickel-release + REACH Annex XVII + RoHS 3 evidence pack into the RFQ.
- Weeks 2-3 — antenna + reader validation
Sample 200-500 fobs with the selected chip; tune reader power so HF tap 0-30 mm and LF tap 0-40 mm are confirmed at every reader; confirm 2.0 m drop + 5-500 Hz vibration.
- Weeks 4-5 — encode + issue workflow
Stand up the encode bench tied to HRIS / ITAM / visitor-management; revocation latency < 10 s; pilot batch rolled to 500-2,000 credentials.
- Weeks 6-10 — premium + food / lab rollout
Deploy across residential / automotive / hospitality premium sites (PVD + laser engraving) and commercial kitchen / food-plant / lab sites (316L brushed + food-contact declaration); audit reads, failures, user hand-feel feedback.
- Month 4+ — estate audit + sustainability reporting
Programme references draw from premium-residential, automotive, food-plant and NEBS data-centre metal-keyfob estates, with periodic compliance reviews, refresh-cycle planning and supplier-onboarding gates customised per vertical. wire credential issue / revoke / retirement events into ISO/IEC 27001 A.11.1 + SOC 2 CC6 + HIPAA 164.310 + PCI DSS v4.0 Req. 9 + WEEE Annex VII metal-stream disposal logs + Higg Index / CDP reporting.
- Pick the alloy first: 316L stainless for food / lab / premium; zinc alloy for high-detail branded fob with epoxy-enamel logo; aluminium for lightweight or colour-library-driven SKUs.
- Specify the ferrite sheet (0.3-0.5 mm) and anti-metal antenna tune per chip choice; HF tap 0-30 mm and LF tap 0-40 mm are the acceptance criteria on PACS reader configuration.
- Close the chemistry audit: EN 1811 nickel release, REACH Annex XVII entries 27 / 63, REACH SVHC screen, RoHS 3 DoC, CA Prop 65 where applicable; food-plant SKUs additionally carry LGA / FDA 21 CFR 175 declaration.
- Finish decision — laser engraving (permanent, serial + logo) for stainless / aluminium; epoxy-enamel (branded logo / enamel inlay) for zinc alloy; PVD gold / rose gold / black for premium cosmetics.
- Revocation + lifecycle are identical to ABS / epoxy variants — PACS revocation within 10 s of HRIS termination; physical retirement defaces the engraved serial and pulls the inlay before sending the shell to WEEE metal stream.
- Order recycling logistics into the programme plan: stainless and aluminium are cleanly separable WEEE streams; plated zinc requires specific plating-strip and zinc-recovery processes under the WEEE Annex VII requirements.
Useful next pages
Use these linked product, guide and comparison pages to keep the next click specific and practical.
Related keyfob and premium-credential options
Alternative keyfob housings and premium-credential adjacents in the catalogue.
FAQ
Is the metal keyfob safe for prolonged skin contact?
Yes — all three alloys (316L stainless, die-cast zinc alloy ZA-4 / ZA-8 with Ni-Cr plating, anodised aluminium 6061 / 7075) pass EN 1811 nickel release at ≤ 0.5 µg/cm²/week and clear REACH Annex XVII entries 27 (nickel) and 63 (lead). 316L stainless and anodised aluminium are the strongest-posture options for nickel-sensitive users; the electroplated zinc variant uses a Ni-Cr top coat specifically sized to stay under the threshold.
Which alloy is suitable for food-plant and commercial-kitchen environments?
316L austenitic stainless steel per ASTM A276, passivated per ASTM A967, is the only food-contact-incidental option under LGA and FDA 21 CFR 175; it tolerates hot-caustic (1-2 % NaOH, 60-80 °C), peracetic-acid (80-150 ppm) and chlorinated-alkaline wash-down indefinitely. Plated zinc alloy is not food-grade because the plating chemistry is not cleared; anodised aluminium is acceptable only when NSF 51 food-grade anodising is specified. Pick 316L stainless for commercial kitchens, food plants, pharma-ancillary areas and labs.
Does the metal shell compromise read range on the reader?
No, provided the 0.3-0.5 mm ferrite sheet is specified between the inlay and the metal lower shell and the antenna is tuned for the anti-metal environment. HF 13.56 MHz tap range is 0-30 mm (vs 0-50 mm in a non-metal shell) and LF 125 kHz tap range is 0-40 mm — in both cases well inside the handshake envelope of every PACS reader we have validated against. The read range is the only spec that changes versus an ABS / epoxy fob; chip, PACS integration, Wiegand / OSDP behaviour are identical.
Sources & references
Primary standards, OEM datasheets and regulatory documents cited by this article. All URLs were verified on the access date shown below.
- ASTM A276/A276M — Standard Specification for Stainless Steel Bars and Shapes
Material specification for 316L austenitic stainless used on the stainless keyfob housing.
- ASTM A967/A967M — Standard Specification for Chemical Passivation Treatments for Stainless Steel Parts
Passivation regime applied to the 316L stainless fob to close the corrosion / nickel-release chemistry.
- EN 1811 — Reference test method for release of nickel from items intended to come into direct and prolonged contact with the skin
Consumer-skin nickel release test — ≤ 0.5 µg/cm²/week threshold used for key-ring items.
- Regulation (EC) 1907/2006 (REACH) — Annex XVII entries 27 (Nickel) and 63 (Lead)
Heavy-metal restriction framework applied to metal keyfob plating and alloy chemistry.
- 21 CFR Part 175 — Indirect food additives: Adhesives and components of coatings
Food-contact-incidental regime governing stainless and food-grade-anodised aluminium keyfob surfaces.
- NSF/ANSI 51 — Food Equipment Materials
Food-equipment-materials standard that food-grade-anodised aluminium variants reference for commercial-kitchen acceptability.
Proud Tek is a Shenzhen-based RFID & NFC manufacturer supplying hotel chains, transit operators, event venues and retail brands worldwide. Every order includes free samples, RF testing and dedicated project support.
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