Kester 275 No-Clean Solder Wire 24-7068-7603 | SAC305 Lead-Free | 0.020" | ROL0 J-STD-004B
Kester 275 No-Clean Solder Wire 24-7068-7603 | SAC305 Lead-Free | 0.020" | ROL0 J-STD-004B
Kester 24-7068-7603 (SKU: 24-7068-7603) is a lead-free SAC305 (Sn96.5/Ag3.0/Cu0.5) no-clean cored solder wire with Kester 275 flux, 0.020" (0.5mm) diameter. The 275 No-Clean flux was developed to provide superior wetting performance for hand soldering in electronics assembly, based on the same chemistry principles as mildly activated rosin fluxes. It produces an extremely clear, colorless post-solder residue that does not require cleaning in most applications. Low spattering and low smoke make it well-suited for production hand soldering environments. Classified ROL0 per J-STD-004B and compliant to Bellcore GR-78.
Key Specifications
| Specification | Value |
|---|---|
| Part Number / SKU | 24-7068-7603 |
| Alloy | SAC305 — Sn96.5/Ag3.0/Cu0.5 |
| Lead-Free | Yes — RoHS compliant |
| Flux Series | Kester 275 No-Clean |
| Flux Content | 2.2% |
| Core Size | 58 |
| Wire Diameter | 0.020" (0.5mm) |
| Flux Classification | ROL0 per J-STD-004B |
| Compliance | Bellcore GR-78 |
| Residue | Colorless, translucent — no cleaning required in most applications |
| Brand | Kester |
Key Features
- Superior wetting performance — excellent solderability and fast wetting to a variety of surface finishes
- Low spattering — unique chemistry reduces spatter common to most core fluxes
- Low smoke and odor — improved operator comfort in hand soldering environments
- Clear no-clean residue — colorless, translucent residue that does not require removal in most applications
- ROL0 classification — per J-STD-004B; non-corrosive, non-conductive residue
- Compatible with lead-free and leaded soldering — 275 flux works with both SAC and SnPb alloys
Frequently Asked Questions
Does the 275 flux residue need to be cleaned after soldering?
In most applications, no — the 275 flux residue is non-corrosive and non-conductive and does not require removal. However, if your process or customer requires residue removal, note that IPA alone will not clean 275 residues. A saponifier or a cleaning agent specifically formulated for no-clean flux removal is required.
What surface finishes is Kester 24-7068-7603 compatible with?
The 275 flux provides excellent wetting and fast solderability to a wide variety of surface finishes including HASL, OSP, ENIG, immersion silver, and immersion tin. It is suitable for most standard PCB surface finishes used in electronics assembly.
What is the wire diameter and are other diameters available?
The 24-7068-7603 is 0.020" (approximately 0.5mm) diameter, a common size for fine-pitch hand soldering and SMT rework. Kester 275 SAC305 solder wire is available in other diameters. Contact MTE Solutions at 651-600-3838 for availability of other sizes in the 275 series.
Is Kester 275 classified as no-clean per J-STD-004?
Yes — Kester 275 is classified as ROL0 per J-STD-004B, the lowest activity level in the rosin/resin flux category. ROL0 fluxes are considered safe to leave as residue on the board in most applications without cleaning.
Can Kester 24-7068-7603 be used for leaded (SnPb) soldering?
Yes — the 275 flux is compatible with both lead-free and leaded soldering alloys. However, the 24-7068-7603 part number specifies SAC305 alloy wire. For SnPb leaded solder wire with 275 flux, a different Kester part number is required. Contact MTE Solutions at 651-600-3838 for leaded 275 series options.
