A practical guide to matching cavity geometry, substrate and coating for the most common Sun Hydraulics T-series cartridge valves.
Why cavity geometry matters
Sun Hydraulics T-series cavities are tightly toleranced, and a single deviation in step diameter or shoulder height can cost the OEM a costly rework cycle. Selecting the right cavity tool starts with a precise match between the SAE-defined cavity drawing and the tool’s profile — JIAYI tools are ground to ±0.005 mm against the master gauge for every batch.
Cavity reference chart
Use this quick lookup to pair the most common Sun T-series cavities with the JIAYI tool family and recommended substrate.
| CAVITY | NOMINAL Ø | TOOL FAMILY | RECOMMENDED SUBSTRATE |
|---|---|---|---|
| T-2A | 9.53 mm | JY-CAV-T2A | K20 sub-micron |
| T-10A | 19.05 mm | JY-CAV-T10A | K20 sub-micron |
| T-11A | 22.23 mm | JY-CAV-T11A | K30 reinforced |
| T-17A | 31.75 mm | JY-CAV-T17A | K30 reinforced |
Substrate selection
For ductile iron and 4140 manifold blocks, a sub-micron carbide grade (K20–K30 range) gives the best balance of edge strength and wear resistance. For 6061-T6 aluminum manifolds, a polished K10 grade with a sharp cutting edge will avoid built-up edge and deliver mirror-finish bores.
Coating recommendations
Coating choice should follow the workpiece, not the cavity size.
- Steel and ductile iron: AlTiN at 80–120 m/min cutting speed.
- Aluminum manifolds: uncoated polished or DLC — never AlTiN.
- Stainless 316L: AlCrN with high-pressure coolant.
Speeds, feeds and coolant
Through-coolant is strongly recommended for T-11A and larger cavities. Maintain 40 bar minimum coolant pressure to evacuate chips from the blind cavity. Reduce feed by 30% on the finishing pass to hold the surface finish under Ra 0.8.
Eight out of ten cavity rejects we audit trace back to coolant pressure, not tool geometry.
