Kester K100LD 24-9574-7610 Lead-Free Solder 0.020 in
- 0.020 inch (0.50 mm) wire, 1 lb spool
- Sn99.3/Cu0.7 lead-free eutectic alloy, 66 core
- 3.3 percent no-clean 275 flux, ROL0 per J-STD-004
- Melting range 227 to 229 C (441 to 444 F)
- Low spatter, low smoke and odor
- Shelf life 1095 days, Bellcore GR-78 compliant
Last refreshed Sep 28, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A lead-free, no-clean flux-core wire for hand soldering electronics, with low spatter, low smoke and a clear residue. The residue resists IPA, so removal needs a dedicated cleaner.
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ASIN: B00FGHTX5AModel: K100LDCategory: Solder
Overview
Hand soldering electronics is the use this series was developed for, pairing a lead-free tin and copper alloy with a flux that needs no cleaning. The chemistry is described as designed to reduce the spattering common to core fluxes.
The residue is colorless, translucent and non-conductive, so most boards need no cleaning at all. The limitation is that removing residue, when required, calls for a saponifier or a cleaner made for no-clean flux, and the halogen content field is ambiguous.
Who it's for
Electronics technicians who hand solder with lead-free alloy and want low smoke and low spatter get a flux designed for that. The listing says the flux can also be used for leaded soldering, so mixed lines are covered.
Pros and cons
- Low spatter, low smoke
- Colorless translucent residue
- Works with lead-free and leaded
- Long stated shelf life
- IPA does not clean residue
- Halogen content field ambiguous
- Material field says lead
Performance notes
Per the description, the flux gives superior wetting for hand soldering and fast wetting across surface finishes. A narrow melting band means the alloy melts over a small temperature span, and the non-corrosive, non-conductive residue generally needs no removal.
Specifications
| Brand | Kester |
|---|---|
| Model | K100LD |
| Dimensions & fit | |
| Wire diameter | 0.020 inches (0.50 mm) |
| Core size | 66 |
| Spool size | Spool, 1 lb |
| Item weight | 1.05 pounds |
| Product dimensions | 2.3 x 2.5 x 2.7 inches |
| Capacity & performance | |
| Melting range | 227 to 229 C (441 to 444 F) |
| Construction & materials | |
| Material | Sn99.3/Cu0.7, lead-free eutectic (K100LD) |
| Other details | |
| Certification | ROL0 per J-STD-004; Bellcore GR-78 compliant |
| Flux content | 3.3 percent |
| Recommended uses | 1095 days |
| Flux type | No-clean, 275 series |
| Liquidus | 229 C (444 F) |
| Flux % | 3.3 % |
| Lead Free | Yes |
Frequently asked questions
Can Kester 275 K100LD be used with leaded solder?
Yes. The description says 275 can be used for both lead-free and leaded soldering.
Can I clean Kester 275 residue with IPA?
No. IPA will not clean the residue. If removal is required, use a saponifier or a cleaning agent designed for no-clean flux.
Does 275 residue need to be removed?
The residues are non-corrosive and non-conductive and do not require removal in most applications.
What is the alloy?
The description gives the composition as 99.3 percent tin and 0.7 percent copper.