Silver-Flo™
SILVER-FLOTM filler metals
SILVER-FLOTM products can be used to join the common engineering metals such as copper, copper alloys (brass, bronze, nickel silver, aluminium bronze, copper nickel), nickel alloys, steel, stainless steel and tungsten carbide.
SILVER-FLO 55 and 56 are general-purpose cadmium-free filler metals combining low brazing temperatures with short melting ranges. Both are free flowing, produce neat joints and are easy to use. They are used as replacements for cadmium-containing filler metals. SILVER-FLO 40 is a popular general-purpose product with medium melt and flow characteristics. SILVER-FLO 302 is a higher- and longer-melting filler metal and a useful gap-filling alloy.
Standard filler metals
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Silver-flo™ 55
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AG
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Cu
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Zn
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Sn
|
ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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55
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21
|
22
|
2
|
Ag 155 | 630 - 660°C |
Silver-flo™ 55 is an easy to use, general purpose silver brazing filler metal. It has a low brazing temperature, short melting range and is free flowing when molten, producing neat joints with small fillets.
Silver-flo™ 55 is a cadmium-free replacement for the high silver (38-50%) cadmium containing filler metals. It can be used on most common engineering metals.
EN1044:1999
AG103
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Silver-flo™ 56
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AG
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Cu
|
Zn
|
Sn
|
ISO 17672
|
Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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56
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22
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17
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5
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Ag 156 | 618 - 652°C |
Silver-flo™ 56 has very similar properties to Silver-flo™ 55. It has a low brazing temperature, short melting range and is free flowing when molten, producing neat joints with small fillets. Originally conforming to the US standard AWS A5.8 BAg-7, it can be used as a cadmium-free replacement for the high silver (38-50%) cadmium containing filler metals.
AMS/AWS A5.8
AMS 4763, AWS Bag-7
EN1044:1999
AG102
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Silver-flo™ 452
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AG
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Cu
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Zn
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Sn
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ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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45
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27
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25.5
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2.5
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Ag 145 | 640 - 680°C |
Silver-flo™ 452 is a general purpose filler metal with 45% silver bridging the gap in properties and cost between high silver 55/56% filler metals and the medium silver 38/40% filler metals. It has the lowest silver content to braze PCD segments below 750˚C without degrading the diamond layer. It has good flow properties, but a slightly higher brazing temperature than the high silver content filler metals.
EN1044:1999
AG104
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Silver-flo™ 40
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AG
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Cu
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Zn
|
Sn
|
ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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40
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30
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28
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2
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Ag 140 | 650 - 710°C |
Silver-flo™ 40 offers a good combination of properties. It has a medium brazing temperature, melting range, flow characteristics and silver content. Silver-flo™ 40 is widely used as a general purpose silver brazing filler metal as well as for joining copper and its alloys to steel in HVAC&R applications.
AMS/AWS A5.8
BAg-28
EN1044:1999
AG105
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Silver-flo™ 38
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AG
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Cu
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Zn
|
Sn
|
ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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38
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31
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29
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2
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Ag 138 | 660 - 720°C |
SILVER-FLO 38 has similar properties to SILVER-FLO 40. It has a medium brazing temperature, melting range, flow characteristics and silver content. SILVER-FLO 38 is favoured in different global regions to SILVER-FLO 40 where it is also used in general purpose and HVAC&R applications.
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Silver-flo™ 302
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AG
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Cu
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Zn
|
Sn
|
ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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30
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36
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32
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2
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Ag 130 | 665 - 755°C |
Silver-flo™ 302 has a long melting range and poor flow characteristics, which make it an ideal choice for applications where fillet build ups are required or close tolerance joint gaps are not present. It is used for brazing steel, copper and copper alloy tubes and fittings in HVAC&R and automotive applications. It is a popular choice as a flux coated rod for site work.
EN1044:1999
AG107
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Silver-flo™ 252
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AG
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Cu
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Zn
|
Sn
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ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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25
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40
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33
|
2
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Ag 125 | 680 - 760°C |
Silver-flo™ 252 has a long melting range and poor flow characteristics, which make it an ideal choice for applications where fillet build ups are required or close tolerance joint gaps are not present. Like Silver-flo™ 302 it may be used for brazing steel, copper and copper alloy tubes and fittings in HVAC&R and automotive applications.
EN1044:1999
AG108
Filler metals for special applications
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Silver-flo™ 60
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AG
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Cu
|
Zn
|
ISO 17672
|
Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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60
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26
|
14
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695 - 730°C |
SILVER-FLO 60 is a filler metal specified for use on copper nickel and nickel alloys (in particular 70:30 copper nickel). It has a brazing temperature above the stress relieving temperature of many of these types of metals thus preventing liquid metal stress cracking as a result of inter-granular penetration. It is resistant to dezincification.
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Silver-flo™ 56S
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AG
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Cu
|
Zn
|
Sn
|
Si
|
|
Melting Range |
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|||
|---|---|---|---|---|---|---|---|---|---|---|---|
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56
|
22
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16.75
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5
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0.25
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618 - 652°C |
Silver-flo™ 56S is a Johnson Matthey proprietary filler metal which has a small addition of silicon, is very free flowing and produces smooth neat joints with small fillets. It is not recommended on carbon steel components that are subject to high impact or fatigue stress in service.
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Silver-flo™ 453S
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AG
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Cu
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Zn
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Sn
|
Si
|
|
Melting Range |
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|||
|---|---|---|---|---|---|---|---|---|---|---|---|
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45
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25
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26.8
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3
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0.2
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640 - 680°C |
Silver-flo™ 453S has a small addition of silicon and produces smooth neat joints with small fillets making it popular for hand torch brazing of decorative brass components. Like other high silver content silicon containing filler metals it is not recommended for use on carbon steel components that are subject to high impact or fatigue stress in service.
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Silver-flo™ 44
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AG
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Cu
|
Zn
|
ISO 17672
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Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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44
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30
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26
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Ag 244 | 675 - 735°C |
Silver-flo™ 44 has a medium brazing temperature, melting range, flow and silver content. Although it is not preferred to the more common Silver-flo™ 40 or 38 it has found use in marine applications because it is resistant to dezincification. It is also used as a medium temperature filler metal for copper alloy tubes where joint gaps are variable and a fillet is desirable.
EN1044:1999
AG203
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Silver-flo™ 43
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AG
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Cu
|
Zn
|
|
Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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43
|
37
|
20
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690 - 775°C |
Silver-flo™ 43 has a medium brazing temperature, long melting range, and poor flow characteristics. It is not commonly used but has found use in the shipbuilding industry and in marine applications because it is the lowest silver content filler metal, which is resistant to dezincification. It is a good fillet forming and gap filling filler metal.
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Silver-flo™ 24
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AG
|
Cu
|
Zn
|
|
Melting Range |
|
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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24
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43
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33
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640 - 800°C |
Silver-flo™ 24 has been incorporated into aviation / aerospace industry standards and is consequently used in the manufacture of components for applications in this field. It is also used as the first alloy in a two-step silver brazing operation, where the second joint is made with Silver-flo™ 55.
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Silver-flo™ 20
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AG
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Cu
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Zn
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Si
|
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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20
|
44
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35.85
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0.15
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776 - 815°C |
Silver-flo™ 20 is a high melting point silver brazing filler metal that has a comparatively narrow melting range providing reasonable flow properties when molten. It can be used when colour matching to brass is required.
Filler metals for less common and reference applications
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Silver-flo™ 45
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AG
|
Cu
|
Zn
|
|
Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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45
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25
|
30
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680 - 700°C |
Silver-flo™ 45 is a cadmium free silver brazing alloy originally developed and manufactured to a Johnson Matthey specification. Today this alloy has been largely superseded by Silver-flo™ 452, and is generally only offered where it is included in an old specification.
Silver-flo™ 45 combines a low brazing temperature with a short melting range. It is very free flowing and produces smooth neat joints with small fillets. The alloy is tin and silicon free. The optimum joint gap at brazing temperature is normally 0.05-0.15mm.Silver-flo™ 44 has a medium brazing temperature, melting range, flow and silver content. Although it is not preferred to the more common Silver-flo™ 40 or 38 it has found use in marine applications because it is resistant to dezincification. It is also used as a medium temperature filler metal for copper alloy tubes where joint gaps are variable and a fillet is desirable.
EN1044:1999
AG203
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Silver-flo™ 34
|
AG
|
Cu
|
Zn
|
Sn
|
ISO 17672
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Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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34
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36
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27.5
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2.5
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Ag 134 | 630 - 730°C |
Silver-flo™ 34 is a cadmium free silver brazing filler metal. It exhibits poor / sluggish flow characteristics melting over a 100°C temperature range. Because of these characteristics Silver-flo™ 34 is not widely used today.
Silver-flo™ 34 has an ability to fill gaps that cannot be tightly controlled and to build fillets. Optimum joint gaps at brazing temperature are 0.075-0.2mm.
EN1044:1999
AG106
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Silver-flo™ 33
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AG
|
Cu
|
Zn
|
|
Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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33
|
33.5
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33.5
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700 - 740°C |
Silver-flo™ 33 is a cadmium free silver brazing filler metal. It shows free flowing characteristics melting over a short, but comparatively high, temperature range (700-740°C). It is a good brazing filler metal that has been used as the second filler metal in a three step sequential brazing process along with Silver-flo™ 16 and Silver-flo™ 55.
Silver-flo™ 33 is not widely used today. Optimum joint gaps at brazing temperature are 0.075-0.2mm.
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Silver-flo™ 30
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AG
|
Cu
|
Zn
|
ISO 17672
|
Melting Range |
|
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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30
|
38
|
32
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Ag 230 | 695 - 770°C |
Silver-fSilver-flo™ 30 is a cadmium free silver brazing filler metal that has been adopted for a thermal spray coating process used in the aerospace industry. It is supplied as a wire on plastic reels suitable for feeding into a thermal spray gun.
The filler metal itself has a long and high melting range and poor flow characteristics hence it is not used as a brazing filler metal to any extent. Optimum joint gaps at brazing temperature are 0.075-0.2mm.
EN1044:1999
AG204
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Silver-flo™ 25
|
AG
|
Cu
|
Zn
|
ISO 17672
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Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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25
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40
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35
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Ag 225 | 700 - 790°C |
Silver-flo™ 25 is a high melting point cadmium free silver brazing filler metal. It has a high melting temperature(700 to 790°C) with a quoted melting range of 90°C. This melting range suggests medium to sluggish flow properties when molten. The high brazing temperature of the filler metal makes it less easy to use than the high silver content alloys.
Optimum joint gaps at brazing temperature are 0.075-0.2mm.
EN1044:1999
AG205
|
Silver-flo™ 18
|
AG
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Cu
|
Zn
|
Si
|
|
Melting Range |
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||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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18
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45.75
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36
|
0.25
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784 - 816°C |
Silver-flo™ 18 is a high melting point cadmium free silver brazing filler metal. It has a high melting temperature(784 to 816°C) but a narrow melting range of only 32°C providing good flow properties when molten. The high brazing temperature of the filler metal makes it less easy to use than the high silver content alloys. Consequently it is not widely used. This product is a relatively inexpensive filler metal to purchase. However the cost per brazed joint of actually using the alloy may not be favourable in comparison to lower melting point, higher silver content filler metals. Optimum joint gaps at brazing temperature are 0.075-0.2mm.
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Silver-flo™ 16
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AG
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Cu
|
Zn
|
|
Melting Range |
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|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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16
|
50
|
34
|
790 - 830°C |
Silver-flo™ 16 is a high melting point cadmium free silver brazing filler metal. It has a high melting temperature(790 to 830°C) but a narrow melting range of only 40°C providing good flow properties when molten.The high brazing temperature of the filler metal makes it less easy to use than the high silver content alloys. Consequently it is not widely used. This product is a relatively inexpensive filler metal to purchase. However the cost per brazed joint of actually using the alloy may not be favourable in comparison to lower melting point, higher silver content filler metals. Optimum joint gaps at brazing temperature are 0.075-0.2mm.
SILVER-FLOTM Brazing pastes and powders
Johnson Matthey's solder pastes consist of a solder alloy in powder form and, optionally as a flux. The components are mixed with a binder to form a paste. Solder pastes offer our customers specifically adapted solutions with unique advantages and are preferably used in batch production. Johnson Matthey has specialists who support you in efficient solder paste use.
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Silver-flo™ 56 brazing paste
|
AG
|
Cu
|
Zn
|
Sn
|
ISO 17672
|
Melting Range |
|
||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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56
|
22
|
17
|
5
|
156 | 618 - 652°C |
Silver-flo™ 56 Brazing Paste is a custom made solution for improving the quality and production rate of brazing operations. It consists of Silver-flo™ 56 powder, a free-flowing, low melting silver brazing filler metal, combined with a flux-binder system to form a smooth dispensible paste.
AMS/AWS A5.8
AMS 4763, AWS Bag-7
EN1044:1999
AG102
|
Silver-flo™ 55 brazing paste
|
AG
|
Cu
|
Zn
|
Sn
|
ISO 17672
|
Melting Range |
|
||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
55
|
21
|
22
|
2
|
156 | 618 - 652°C |
Silver-flo™ 55 brazing paste is a specially formulated paste product intended for use in semi- or fully automated brazing processes or where the use of a paste offers other advantages. It combines Silver-flo™ 55, a filler metal with excellent brazing characteristics, in powder form with a flux-binder system selected to match an individual application. The resulting product is a fully dispensable custom-made brazing paste.
EN1044:1999
AG103
|
Silver-flo™ 40 brazing paste
|
AG
|
Cu
|
Zn
|
Sn
|
ISO 17672
|
Melting Range |
|
||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
40
|
30
|
28
|
2
|
140 | 650 - 710°C |
SILVER-FLO 40 brazing paste is a specially formulated paste product intended for use in semi- or fully automated brazing processes or where the use of a paste offers other advantages. It combines SILVER-FLO 40, a filler metal with good general brazing characteristics, in powder form with a flux-binder system selected to match an individual application. The resulting product is a fully dispensable custom-made brazing paste.
EN1044:1999
AG105
|
Silver-flo™ 24 brazing paste
|
AG
|
Cu
|
Zn
|
|
Melting Range |
|
|||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
24
|
43
|
33
|
6740 - 800°C |
SILVER-FLO 24 brazing paste is a specially formulated paste product intended for use in semi- automated brazing processes or where the use of a paste offers other advantages. It combines SILVER-FLO 24, a comparatively high melting temperature silver brazing filler metal, in powder form with a flux-binder system selected to match an individual application. The resulting product is a fully dispensable custom-made brazing paste.
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Silver-flo™ 55 paint
|
AG
|
Cu
|
Zn
|
Sn
|
|
Melting Range |
|
||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
55
|
21
|
22
|
2
|
630 - 660°C |
SILVER-FLO 55 Paint consists of a silver brazing filler metal powder (SILVER-FLO 55) and a brazing flux (EASY-FLO™ Flux Powder) combined in a volatile organic solvent. The proportions of filler metal to flux are optimised to make the paint suitable for brazing small components by most heating methods.
The silver brazing filler metal in this product - SILVER-FLO 55, is cadmium-free. It combines a low brazing temperature with a short melting range, is very free flowing and produces neat joints with small fillets. These characteristics make it an excellent general purpose silver brazing filler metal.
Joints made with SILVER-FLO 55 Paint are suitable for seawater applications, being resistant to dezincification. The optimum joint gap for this filler metal at brazing temperature is normally 0.05-0.15mm.
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