---
title: "Platinum Thermocouple Wire: How to Sell This Valuable Alloy"
source: "https://goldealers.co.uk/knowledge/platinum-palladium/platinum-thermocouple-wire"
date: "2025-12-02"
---

# Platinum Thermocouple Wire: How to Sell This Valuable Alloy

Not all precious metal scrap comes from jewellery – some comes from industry. Platinum thermocouple wire is a prime example of a high-value industrial scrap that many people outside the lab world may not even know about. If you've stumbled upon platinum thermocouple wires (perhaps during a lab decommissioning, furnace replacement, or instrument upgrade), you should know they contain precious metals worth recovering.

> **Quick Summary:** Platinum thermocouple wires contain valuable platinum-rhodium alloys. Type B wires (30% rhodium) are especially valuable. A small coil can be worth hundreds of pounds, but you'll need to find a specialist precious metal refiner to sell them properly.

## What Are Platinum Thermocouple Wires?

Thermocouples are temperature sensors used in industrial and laboratory equipment to measure extremely high temperatures. Certain types of thermocouples are made using platinum and rhodium alloys – these are known as Type B, R, and S thermocouples.

### Thermocouple Types and Compositions

Each type has a specific Platinum/Rhodium composition:

| Type | Composition | Maximum Temperature | Typical Use |
|------|-------------|---------------------|-------------|
| Type S | ~90% Platinum, 10% Rhodium | Up to ~1600°C | Laboratory applications |
| Type R | ~87% Platinum, 13% Rhodium | Up to ~1600°C | Similar to Type S |
| Type B | ~70% Platinum, 30% Rhodium | Up to ~1700°C | Very high temperature applications |

> Type B wires are especially valuable due to the higher rhodium content (30%). Given rhodium's extremely high price, these wires can be worth significantly more per gram than Types R or S.

### How Thermocouples Work

These wires usually come as a pair (one wire of Pt/Rh alloy, one of pure platinum or another alloy), forming a circuit that generates a tiny voltage at high temperatures. Over time, or when equipment is retired, you may end up with lengths of spent thermocouple wire.

Learn more about [rhodium's value](/knowledge/platinum-palladium/selling-rhodium-and-rhodium-plated-items) to understand why Type B wires command premium prices.

## Assessing What You Have

If you have thermocouple wire scrap, first identify its type:

### Look for Labeling or Paperwork

Often, thermocouple wires might be tagged or the equipment manual will state the type (S, R, or B). Old purchase orders or spec sheets are very handy – they'll tell you the exact alloy composition.

### Physical Properties

**Platinum Characteristics:**
- Platinum thermocouple wires typically look like thin, silvery wires
- They are not magnetic
- They do not oxidise (they might have a bit of discoloration from high heat, like a slight gray scale, but no rust)

**Weight:** These wires are heavy for their size (platinum is dense). Weigh what you have – even a few grams can be worthwhile. Note that if it's still in a protective sheath or ceramic insulator, you should separate the pure metal wire for an accurate weight, if possible.

### Don't Mix Types

> If you have different batches, try to keep known types separate. Type B (30% Rh) is worth more per gram than Type S (10% Rh) because of the rhodium difference. A refiner will assay the material anyway, but knowing upfront helps you estimate value.

If you are unsure of the type and there are no markings or docs, a professional assay (using XRF analysis or a chemical test) will be needed. Reputable buyers can do this testing. See our guide on [testing platinum and palladium](/knowledge/testing/testing-platinum-palladium).

## Why Regular Scrap Buyers Might Decline

It's important to understand that selling thermocouple wire is not like selling a gold necklace. Many ordinary precious metal buyers (and certainly pawn shops) may not know how to deal with platinum-rhodium alloy wire.

### Reasons Buyers May Pass

1. **Appearance:** The metal looks unassuming (just grey wire) and could be mistaken for steel or nichrome by the untrained eye

2. **High Rhodium Content:** Not every smelter can process rhodium, as it has a very high melting point and requires specialised refining

3. **Complex Valuation:** Valuing it requires up-to-date pricing for both platinum and rhodium, and an accurate composition analysis. This is beyond the scope of a simple acid test kit

> Don't be discouraged if local jewellers or scrap dealers pass on thermocouple wire. Your best route is to find a precious metal refiner or a specialised PGM buyer (like a company that advertises buying industrial platinum, lab equipment, or thermocouples).

## How Selling Works and Getting Paid

When you send platinum thermocouple wire to a refiner or specialised buyer, here's what typically happens:

### 1. Assay and Analysis

The buyer will determine the exact platinum and rhodium content. This might involve:
- Taking a small sample and using XRF (X-ray fluorescence)
- Performing a melt and chemical assay
- They do not just guess – given the high value, they will be precise

### 2. Valuation

Your payout is based on:
- The metal content (Platinum and Rhodium both) multiplied by current market prices
- Minus a refining fee or margin
- Most reputable refiners pay somewhere around 90%–98% of the total metal value for PGM industrial scraps like this

**The exact percentage depends on:**
- The weight you have (large quantities get closer to 98%)
- How clean the material is (wire that's not contaminated with other materials will yield a higher return)

### 3. Offer and Payment

The refiner will usually:
- Confirm the weight and assay results
- Present you with an offer
- Once you agree, payment is made (usually via bank transfer or cheque)
- Payment could take a couple of weeks in total, especially if a full melt/refine is done
- Some buyers might advance a portion of payment on receipt and finalise after refining

### 4. Logistics

> **Important:** Transporting thermocouple wire scrap should be done securely. If using post/courier, ensure it's insured. Given the high value in a small package, use guaranteed delivery services or even specialised courier for large amounts.

Follow the buyer's packing instructions; many will provide an insured Royal Mail Special Delivery pack or even arrange a secure pickup for large lots. See our guide on [packaging precious metals for posting](/knowledge/postal/how-to-package-gold-silver-posting).

## Tips to Maximise Your Return

### Shop Around

Not every refiner offers the same rates for platinum/rhodium scrap. It's wise to get quotes from at least two reputable companies. Provide them the weight and known type (if known) to get a preliminary estimate.

### Keep Documentation

If you have any certificates or labels indicating the alloy (say the wires were labeled "Type B 70Pt/30Rh"), include that information. It helps build trust and speed up valuation.

### Clean the Material

Remove any non-metal attachments (ceramic insulators, clamps, etc.) if you can do so without losing any wire:
- Refiners will deduct for non-metal weight
- Do not attempt to burn off insulation yourself (platinum can be damaged by impurities at high temps)
- Mechanical removal is fine

### Batch Sales

If you also have other platinum group scrap (say some pure platinum wire or pieces of a used platinum crucible), ask the refiner if they can be processed together or offer a bonus for a larger batch. Just ensure different materials are bagged separately with labels.

> Combine your platinum scrap sales when possible. You might also have [other platinum items](/knowledge/platinum-palladium/selling-platinum-scrap) or [iridium equipment](/knowledge/platinum-palladium/selling-iridium-scrap) from the same lab.

### Understand Taxes

If you're selling on behalf of a business, there may be VAT implications for recovered precious metals. As an individual, selling scrap metal generally isn't taxable income, but if it's a very large amount, you might want to check if any capital gains apply.

Learn more about [VAT on precious metals](/knowledge/tax-vat/vat-on-gold-silver-platinum).

## Value Example

To illustrate the potential value:

**Type B Thermocouple Wire (70% Pt, 30% Rh):**
- Small coil weighing 10 grams
- Contains approximately 7g platinum and 3g rhodium
- At current market prices (Pt ~£30/g, Rh ~£150/g):
  - Platinum value: £210
  - Rhodium value: £450
  - Total metal value: £660
- At 90% payout: **£594**

This demonstrates why it's absolutely worth selling these "innocuous wires" rather than throwing them out!

## Frequently Asked Questions

**Q: How do I know what type of thermocouple wire I have?**  
A: Check for labeling on the wire itself, tags, or equipment documentation. If there are no markings, a professional refiner can perform an XRF test or chemical assay to determine the exact composition.

**Q: Why won't my local jeweller buy my thermocouple wire?**  
A: Most jewellers and pawn shops don't have the equipment or expertise to handle platinum-rhodium alloys. They typically focus on gold and silver jewellery. You need a specialised precious metal refiner who deals with industrial PGM scrap.

**Q: What percentage of the metal value will I receive?**  
A: Reputable refiners typically pay 90-98% of the total metal value for platinum-rhodium thermocouple wire. The exact percentage depends on the quantity, purity, and cleanliness of the material. Larger batches generally receive higher percentages.

**Q: Should I remove the ceramic insulators before selling?**  
A: Yes, if you can do so safely without losing any wire. Refiners will deduct for non-metal weight. However, don't use heat or aggressive methods that might damage the wire – mechanical removal only.

**Q: How long does the selling process take?**  
A: From sending the material to receiving payment typically takes 2-4 weeks. This includes shipping time, assay, and refining. Some refiners may offer partial advance payment upon receipt.

## Next Steps

Platinum thermocouple wires are highly valuable scrap due to their platinum and rhodium content. It's absolutely worth doing it right when selling them – which means using the right buyer and not settling for a low offer from someone who isn't familiar with the material.

With proper handling, you can recover a significant amount of money from those seemingly innocuous wires. Don't throw them out – cash them in!

**Useful Resources:**
- [Selling Platinum Scrap: Value and How to Sell](/knowledge/platinum-palladium/selling-platinum-scrap)
- [Selling Rhodium and Rhodium-Plated Items](/knowledge/platinum-palladium/selling-rhodium-and-rhodium-plated-items)
- [How Platinum and Palladium Are Tested](/knowledge/testing/testing-platinum-palladium)
- [How to Package Precious Metals for Posting](/knowledge/postal/how-to-package-gold-silver-posting)

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*Published by Goldealers Ltd · https://goldealers.co.uk/knowledge/platinum-palladium/platinum-thermocouple-wire*