A carbide blade skives the bore to size while tapered rollers cold-work the surface — one head, one pass, no coolant-borne abrasive. The standard way hydraulic cylinder barrels, gun tubes and long actuators go from drilled to finished.
SRB combines two mechanical actions in one tool head. First a carbide skiving blade cuts a thin, uniform layer off the bore wall (typically 0.1–0.4 mm) to remove drilling distortion, taper and tooling marks. Immediately behind it, three to five tapered rollers press the freshly cut surface — cold-working the peaks down to the level of the valleys. The rollers are self-centering, so the head follows the bore axis.
| Stage | Tool element | Action | Stock / effect |
|---|---|---|---|
| Skive | Carbide blade | Shears a thin layer off the wall | 0.1–0.4 mm removed |
| Burnish | 3–5 tapered rollers | Cold-work & flatten roughness peaks | Ra 0.4→0.1–0.4 μm, work-hardened surface |
BTA or ejector drill the barrel undersized to depth (leave 0.3–0.6 mm/side on the bore radius).
For long, heavy-wall barrels, stress-relieve before finishing so the bore does not move after roughing.
One continuous pass to depth. The skiving blade cleans up the drilled geometry; the rollers set the finish and size.
Measure size, roundness, straightness and surface. Adjust blade projection (diameter) and roller force for the next barrel.
| Criteria | Skive & Roller Burnish | Honing |
|---|---|---|
| Cycle time | One pass, feed 0.3–1.0 mm/rev — fastest for long bores | Reciprocating; slower per metre |
| Surface finish | Ra 0.1–0.4 μm, burnished (compressive, low friction) | Ra 0.05–0.8 μm with crosshatch for oil retention |
| Stock removal | 0.1–0.4 mm/pass (limited) | 0.01–0.2 mm typical, more controllable in-situ |
| Blind-end bores | Not practical — needs through bore for tool exit | Works to a blind shoulder |
| Surface texture | Bright, non-directional, low friction | Crosshatch pattern holds oil |
| Tooling cost | One carbide blade + rollers, no abrasive | Abrasive stones, more consumables |
Combined SRB heads mount the skiving blade and the tapered rollers on one body, adjustable for diameter by shims or an adjusting ring. The tool rotates and feeds through the bore (workpiece stationary) on a deep-hole finishing machine, or the workpiece rotates on a lathe-type layout. Heads are sized in millimeters by finish bore diameter.