Braze Paste

Alumasil™ Braze Paste

Premium aluminum brazing paste engineered for furnace brazing of complex heat exchanger assemblies. Six formulations covering standard to wide-gap applications, with Cesium variants for magnesium-bearing alloys.

577–612°C
Active Range
2,500–85,000
Viscosity (cP)
10–50%
Flux Content
6
Formulations

Product Overview

Alumasil™ Braze Paste combines fluxing agents and aluminum-silicon brazing alloy in a single paste system, simplifying application and improving joint consistency. It is purpose-built for furnace brazing of tube-to-header, manifold, tube-to-block, and other challenging assembly configurations found in HVAC and automotive heat exchangers.

The three base grades differ in liquidus temperature and silicon content, which determines their gap-filling capability. The FX12 grade suits tight, precision-fit joints; FX10 bridges moderate gaps; and FX7 provides the widest active temperature range and best gap-filling for difficult assemblies. Each grade is available with or without Cesium Fluoride.

Key Features

  • Application-specific formulation — six grades to match joint clearance and alloy
  • Minimal nozzle clogging — auto-dispense compatible
  • Consistent paste distribution and viscosity across temperature
  • Clean burnoff below 175°C — no pre-clean required before furnace
  • Low settling characteristics — long pot life
  • Excellent adhesion to aluminum components
  • Cesium variants for Mg-bearing alloys (3xxx, 5xxx)
  • Application: auto-dispense or manual

Grade Comparison

Cs = Cesium Fluoride variant for magnesium-bearing aluminum alloys

Grade Active Range Gap Filling Application Viscosity Flux Content
FX12 577–585°C Standard Auto-Dispense / Manual 2,500–85,000 cP 10–50%
FX12Cs Cs 577–585°C Standard Auto-Dispense / Manual 2,500–85,000 cP 10–50%
FX10 577–591°C Better Auto-Dispense / Manual 2,500–85,000 cP 10–50%
FX10Cs Cs 577–612°C Better Auto-Dispense / Manual 2,500–85,000 cP 10–50%
FX7 577–612°C Best Auto-Dispense / Manual 2,500–85,000 cP 10–50%
FX7Cs Cs 577–612°C Best Auto-Dispense / Manual 2,500–85,000 cP 10–50%

Grade Selection Guide

GradeBest forJoint Clearance
FX12 / FX12CsPrecision-fit assemblies, tight tolerancesNarrow (0.05–0.15 mm typical)
FX10 / FX10CsStandard heat exchanger assemblies with moderate gapMedium (0.10–0.25 mm typical)
FX7 / FX7CsDifficult assemblies, wide joints, oil coolers, manifoldsWide (up to 0.5 mm)

Applications

Tube-to-header
Tube-to-manifold
Tube-to-block
Oil coolers
Evaporators
Radiators
Charge air coolers
Condensers

Packaging

10 kg 20 kg 25 kg 20 lb 40 lb 50 lb

Supplied in plastic containers. Custom volumes and private-label packaging available on request.

Request Technical Data Sheet

Full TDS, SDS, and grade selection guidelines available on request.

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