A PISTON RING STD. specification indicates the piston ring set is for a STANDARD bore size engine, meaning it is the original, un-machined diameter for that engine model. Key specs generally include the ring’s end gap (how much it overlaps when fitted to the piston), its thickness, its radial wall thickness (front-to-back measurement), its material (like cast iron or ductile iron), and its coatings (such as nitriding for wear resistance).
| Weight | 0.030 kg |
|---|---|
| Purpose: | Seals combustion gases, prevents blow-by. |
| Material: | Cast iron, ductile iron, or steel (with chrome/moly coating). |
| Thickness (axial height): | 1.0 – 1.5 mm (motorcycles), 1.2 – 2.0 mm (cars). |
| End Gap (installed): | 0.20 – 0.40 mm (motorcycles), 0.25 – 0.50 mm (cars). |
| Side Clearance (in groove): | 0.02 – 0.05 mm. |
| Hardness: | ~250–300 HB (coated versions up to 400 HB). |
| PART NUMBER: | 13011-KPH-900, 13011-K60-305 |





