Paste Solder Fluxes

Non-Corrosive Fluxes: Fluxes are classified as Non-Corrosive when their residue after soldering will not corrode and eventually destroy the joint if allowed to remain. Generally incorporating a rosin base, these fluxes contain mild organic acids which are neutral at room temperature but become slightly acidic upon heating. Neutral, rosin fluxes are particularly useful in electrical applications, where their non-conductive, non-corrosive residue may be safely left on the assemblies.

Intermediate Fluxes: These fluxes usually consist of mild organic salts, with considerably stronger fluxing action than non-corrosive types. Residue after soldering is normally not harmful to the soldered joint. However, residue should be removed whenever possible, as moisture in the atmosphere may initiate corrosion.

Corrosive Fluxes: Most corrosive fluxes contain active inorganic acids and salts. Due to their increased strength and ability to quickly remove surface oxides, these fluxes are ideally suited to high-speed, automated soldering operations. Although corrosive fluxes generally produce the most reliable soldered joints, their residue after soldering must be removed, or it will eventually attack and destroy the joint.

 

Non-Corrosive

Flux Type	Fluxing Range*	Suggested to Remove Residue	Flow Traits	Recommended for Use On
				Copper & Brass**	Steel	Plated Surfaces	Stainless Steel
GPR	300-525°F 149-273°C	Mineral Spirits or Chlorinated Hydrocarbon Solvent	Fair Spread	Yes	No	LT	No
LPS	300-525°F 149-273°C	Mineral Spirits or Chlorinated Hydrocarbon Solvent	Restrictive	Yes	No	LT	No
LPT	300-525°F 149-273°C	Mineral Spirits or Chlorinated Hydrocarbon Solvent	Restrictive	Yes	No	LT	No
MBC	450-595°F 232-313°C	Mineral Spirits or Chlorinated Hydrocarbon Solvent	Restrictive	Yes	No	LT	No

*	Extended heating times can cause fluxes to oxidize prematurely
**	Unusual service conditions may facilitate stress corrosion of certain brass parts joined with fluxes containing ammonia. Laboratory evaluation suggested.
LT	Laboratory testing is recommended due to widely varied metallurgical surface conditions.

 

Intermediate

Flux Type	Fluxing Range*	Suggested to Remove Residue	Flow Traits	Recommended for Use On
				Copper & Brass**	Steel	Plated Surfaces	Stainless Steel
WC	300-525°F 149-273°C	Hot Water	Stays in place, little spread until molten.	Yes	Mild (LT)	Most (LT)	(LT)
PMS	300-525°F 149-232°C	Hot Water	Stays in place, little spread until molten.	Yes	Mild (LT)	Most (LT)	300 Series (LT)
PWC/ WCN	300-525°F 149-232°C	Hot Water	Stays in place, little spread until molten.	Yes	Mild (LT)	Most (LT)	300 Series (LT)
PA	300-450°F 149-232°C	Hot Water	Stays in place, little spread until molten.	Yes	Mild (LT)	Most (LT)	300 Series (LT)
PAN	125-300°F 52-149°C	Hot Water	Stays in place, little spread until molten.	Yes	Mild (LT)	Most (LT)	300 Series (LT)

*	Extended heating times can cause fluxes to oxidize prematurely
**	Unusual service conditions may facilitate stress corrosion of certain brass parts joined with fluxes containing ammonia. Laboratory evaluation suggested.
LT	Laboratory testing is recommended due to widely varied metallurgical surface conditions.

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Corrosive

Flux Type	Fluxing Range*	Suggested to Remove Residue	Flow Traits	Recommended for Use On
				Copper & Brass**	Steel	Plated Surfaces	Stainless Steel
SSE	250-600°F 121-316°C	Hot Detergent Water	Stays in place, little spread until molten.	Yes	Most (LT)	Most (LT)	300&400 Series (LT)
SMH	300-600°F 149-316°C	Hot Detergent Water	Stays in place, little spread until molten.	Yes	Most (LT)	Most (LT)	300&400 Series (LT)
WCE	300-600°F 149-316°C	Hot Detergent Water	Stays in place, little spread until molten.	Yes	Most (LT)	Most (LT)	Most (LT)

*	Extended heating times can cause fluxes to oxidize prematurely
**	Unusual service conditions may facilitate stress corrosion of certain brass parts joined with fluxes containing ammonia. Laboratory evaluation suggested.
LT	Laboratory testing is recommended due to widely varied metallurgical surface conditions.

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