UNS C14500
Tellurium Copper
Fasteners
Why Tellurium Solves Copper’s Machining Problem
Pure, unalloyed copper has an inherent manufacturing weakness — it’s gummy and difficult to machine cleanly, tending to smear and produce long, stringy chips rather than breaking cleanly, which slows production and reduces tool life on any part that requires threading, turning, or drilling. For fasteners specifically, where thread cutting is unavoidable, this is a genuine, practical obstacle.
Tellurium copper solves this with a very small tellurium addition — typically well under 1% — which forms fine, dispersed particles within the copper matrix that act as internal chip-breakers during machining, without meaningfully degrading copper’s exceptional electrical and thermal conductivity. The result retains roughly 95–98% of pure copper’s International Annealed Copper Standard (IACS) conductivity rating while machining dramatically more like a free-cutting brass.
That combination is precisely what makes tellurium copper the practical, correct choice for high-conductivity fastening hardware — busbar connections, grounding hardware, and electrical terminal fastening all genuinely benefit from minimizing electrical resistance at the joint, something a lower-conductivity brass or bronze fastener cannot match, while still being manufacturable at production volumes and reasonable cost.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our UNS C14500 fastener range is manufactured and verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Material Genuinely Applies
Near-Native Copper Conductivity
Approximately 95–98% IACS, meaningfully higher than brass or bronze fastener alternatives.
Genuinely Free-Machining
Tellurium’s chip-breaking particles solve pure copper’s gummy machining behavior.
Production-Efficient
Manufacturable at commercial volumes without the tooling penalties of pure copper.
Verified Mechanical Properties
Batch testing confirms genuine tellurium content and conductivity for every lot.
UNS C14500 vs Brass — Quick Reference
Confirming whether electrical conductivity at the joint is genuinely the driving requirement before choosing tellurium copper over a lower-cost brass fastener. This table is the quick reference we use with buyers before quoting.
| Aspect | UNS C14500 Tellurium Copper | Standard Brass (e.g. C36000) |
|---|---|---|
| Electrical Conductivity | ~95–98% IACS | ~26–28% IACS |
| Machinability | Free-machining, tellurium-enhanced | Free-machining, standard |
| Relative Strength | Lower | Higher |
| Best Suited For | High-conductivity electrical joints | General mechanical fastening |
UNS C14500 Specification Details
Nominal Composition
- Copper ~99.4% Minimum
- Tellurium ~0.40 – 0.70%
- Phosphorus Small Controlled Addition
- Other Elements Trace, Controlled
Typical Property Range
- Electrical Conductivity ~95 – 98% IACS
- Thermal Conductivity Near-Native Copper
- Condition Cold Worked / Annealed
- Machinability Rating Excellent
Fastener Types We Manufacture
- Hex Bolts & Studs Standard & Custom Sizes
- Hex Nuts Standard & Heavy Hex
- Terminal Lugs & Connectors Custom Machined
- Custom Machined Parts On Request
Application Areas
Wherever electrical conductivity at the fastened joint is genuinely the driving performance requirement.
Busbar & Switchgear Connections
joints needing low resistance
Grounding & Earthing Hardware
system fastening
Transformer & Substation Terminals
connection hardware
Electronics & Precision Machined Parts
conductive components
Standard Export Documentation
Prepared as standard practice for every UNS C14500 fastener shipment.
Mill Test Certificate (MTC)
Heat/lot number, chemical composition, and conductivity verification for every batch.
Chemical Composition Report
Confirms actual copper and tellurium content fall within the specified UNS C14500 range.
Certificate of Conformance
Confirms the shipment matches the purchase order specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
Electrical Conductivity Report
Confirms IACS conductivity percentage for conductivity-critical applications.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
UNS C64200 Aluminium Silicon Bronze
Our related copper-based alloy, valued for seawater and galling resistance rather than conductivity.
View UNS C64200 →ASTM A194 Grade 8 Nuts
Our standard stainless grade, the common alternative where conductivity isn’t the primary requirement.
View Grade 8 Nuts →ASTM A194 Grade 1 Nuts
Our general-purpose carbon steel grade, for general mechanical fastening without conductivity requirements.
View Grade 1 Nuts →Stainless Steel Fasteners Manufacturer India
Our broader fastener manufacturing capability across all major carbon, alloy, stainless, and non-ferrous grades.
View SS Manufacturer Guide →Need High Conductivity
& Machined Precision?
Tell us your application and required conductivity level — we’ll confirm whether tellurium copper fits, and quote with full documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in