Hakko T18-S4 Ultra Fine Conical Solder Tip, 0.125Mm
Hakko T18-S4 — Ultra Fine Conical Solder Tip, 0.125mm
The Hakko T18-S4 is a 0.125mm ultra fine conical solder tip for the Hakko FX-888D, FX-888, and legacy 900M/936/937 series soldering stations. The T18-S4 is the finest tip in the entire T18 series, tapering to a 0.125mm point for the most demanding micro-precision applications: rework and placement of 0201, 01005, and ultra-fine-pitch components; individual lead touch-up on high-density ICs; micro wire attachment; and any task where even a 0.20mm tip is too coarse. At this scale, technique, station stability, and tip care are critical to successful joints.
Key Specifications
| Specification | Value |
| Part Number / SKU | T18-S4 |
| Series | T18 |
| Tip Style | Ultra Fine Conical (S-type) |
| Tip Diameter | 0.125mm |
| Compatible Stations | FX-888D, FX-888, 936, 936-ESD, 937, 928, 913, 907, 907-ESD, 900M, 900M-ESD, 703 |
| Replaces | 900M series tips |
Compatible Stations
- Hakko FX-888D Soldering Station
- Hakko FX-888 Soldering Station
- Hakko 936 / 936-ESD Soldering Station
- Hakko 937 Soldering Station
- Hakko 928 Soldering Station
- Hakko 913 ESD Safe Fume Extraction Iron
- Hakko 907 / 907-ESD Soldering Iron
- Hakko 900M / 900M-ESD Soldering Iron
- Hakko 703 Soldering Station
- Replaces 900M series tips
Soldering Tip Care Guide
- Tin before and after every use — without exception — a 0.125mm tip oxidizes almost instantly when bare at temperature. Always maintain a solder coat on the point.
- Use brass wire tip cleaner with extreme gentleness — barely touch the tip into brass wool (Hakko 599B-02); the 0.125mm point can be deformed or broken with normal cleaning force. Never use a wet sponge.
- Re-tin after every single cleaning touch — do not make multiple cleaning strokes before re-tinning at this tip size.
- Use tip tinner/activator immediately at any sign of dewetting — oxidation progresses extremely rapidly on a 0.125mm point; do not delay treatment.
- Use the absolute lowest effective temperature setpoint — every degree of excess heat accelerates tip degradation at this scale.
- Replace immediately upon any deformation, pitting, or unrecoverable dewetting — a damaged T18-S4 cannot be salvaged for precision work.
Frequently Asked Questions
How does the T18-S4 compare to the T18-I and T18-BL?
The T18-S4 at 0.125mm is finer than both the T18-I (0.20mm standard-length conical) and the T18-BL (0.20mm long conical). It is the finest tip in the T18 lineup and should only be selected when 0.20mm is demonstrably too coarse for the work. For most micro-precision rework, the T18-I (0.20mm) is the recommended starting point; step down to the T18-S4 only when component geometry or pad density genuinely requires it. The T18-S4 is more fragile, oxidizes faster, and requires more careful handling than any other tip in the T18 series.
What component sizes is the T18-S4 designed for?
The T18-S4 is designed for 0201 (0.6 × 0.3mm) and 01005 (0.4 × 0.2mm) passives, ultra-fine-pitch IC leads with pitch below 0.3mm, and any micro-rework task where a 0.20mm tip risks bridging adjacent pads or components. At these component sizes, temperature control, flux selection, and tip condition are as important as tip geometry.
What stations is the Hakko T18-S4 compatible with?
The T18-S4 is compatible with the Hakko FX-888D, FX-888, 936, 936-ESD, 937, 928, 913, 907, 907-ESD, 900M, 900M-ESD, and 703 soldering stations and irons. It is not compatible with the FX-951 (T15 series) or FX-971/FX-972 (T39 series).
How do T18 tips differ from T15 and T39 series tips?
T18 tips are designed for the FX-888D/FX-888 and legacy 900M/936 series stations. T15 tips are for the now-discontinued FX-951 station. T39 tips are for the current FX-971 and FX-972 stations. The three series are not interchangeable — always match the tip series to your specific station model.
