# Soldering Flux Paste Castolin 5000FX AG, hard solder flux, 125 g

**URL:** https://aio.lv/en/product--castolin-755093--11916007
**Data updated:** 2026-03-10 09:20 (EET)
**Category:** Miscellaneous repair tools
**Manufacturer:** Castolin
**Manufacturer code:** 755093
**EAN:** 3509350011034
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 25.99 €
**Prices and availability valid until:** 2026-07-11 23:59
**Price without VAT (21%):** 21.48 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--castolin-755093--11916007

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 02.07.2026 | free |
| Pickup points | 07.07.2026 | 1.99 EUR |
| Courier delivery to door | 07.07.2026 | 4.99 EUR |

## Summary description

Castolin 5000FX AG is a hard-solder flux paste supplied in a 125 g tube for use with silver and hard brazing alloys. The product removes oxides, promotes wetting and joint formation, and is intended for metal joining and repair tasks in plumbing, HVAC and light industrial applications. Use with appropriate protective measures and post-cleaning.

## Long description

Castolin 5000FX AG is a hard-solder flux paste supplied in a 125 g tube, formulated for use with silver and other hard brazing alloys. It is designed to remove surface oxides, promote wetting of base metals and filler materials, and support formation of reliable brazed joints. The product is intended for metal joining and repair tasks in plumbing, HVAC and light industrial applications where controlled flux application and post-process cleaning are required.
Advantages
This flux paste adheres well to vertical and overhead joints, providing localized protection against oxidation during heating and ensuring good flow of silver and hard brazing alloys. Its paste consistency allows precise application from the tube, minimising waste and over-application. After brazing, residues can be removed with appropriate cleaning agents, helping maintain joint appearance and preventing long-term corrosion when followed by correct cleaning procedures.
Suitable for
 Brazing copper and copper alloys in plumbing and refrigeration systems
 Joining components in HVAC installations and maintenance
 Light industrial repair and assembly requiring silver or hard filler metals
 Field repairs where a tube-applied flux provides convenient, localised application
Key specifications
 Form: paste in a squeezable 125 g tube for controlled application
 Compatibility: formulated for use with silver and other hard brazing alloys
 Function: oxide removal and promotion of wetting and filler flow during brazing
 Application temperature: suitable for typical hard-brazing temperature ranges (consult filler alloy data for exact values)
 Residue: requires post-brazing cleaning to remove flux residues for corrosion prevention
How to use
Prepare joint surfaces by removing loose scale, grease and heavy contaminants; ensure mating surfaces fit closely. Apply an even, thin layer of flux paste from the tube to the heated area or joint faces where the filler metal will flow. Heat the assembly evenly to the recommended brazing temperature for the chosen silver or hard alloy and apply filler metal once flux becomes active and base metal reaches proper temperature. Allow the joint to cool, then remove residual flux with suitable cleaners or solvents in accordance with safety data and manufacturer guidance.
Usage recommendations
Use appropriate personal protective equipment, work in a well-ventilated area and follow local safety regulations. Avoid excessive flux application and ensure thorough post-braze cleaning to prevent corrosion. Store the tube capped in a cool, dry place and keep away from children and untrained personnel.

## FAQ

### How much does the Castolin 5000FX AG flux paste, 125 g cost, and is it available for purchase?

The price is 25.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 2 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 02.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Castolin products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Castolin service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/11916007/67347770_large.webp