Professional O-Ring and Oil Seal Manufacturer, Sealing Solution Supplier Since 2008.
Semi-finished material FKM FPM VITON Tube
Color: Brown / Black
Hardness: 85 shore A
Temperature: -20 to 200℃
1. Basic Definition
An FKM semi-finished tube is a fully vulcanized fluororubber hollow billet, formed by extrusion + molding cure. The outer/inner diameters leave machining allowance so that customers can directly CNC-turn them into a variety of precision seals. Compared with molded single parts, this approach suits multi-specification, small-batch seal production and avoids tooling/die costs.
2. Media / Chemical Compatibility
✅ Good resistance: mineral oils, synthetic lubricants, gasoline/diesel, hydrocarbon fuels, dilute acids, ozone, aging, steam, oxidative environments, low gas permeability.
❌ Not recommended: concentrated strong alkalis, amines, ketones, ethyl acetate, some esters, high-temperature saturated steam.
3. Dimensions & Tolerances (Semi-finished Tube)
- Shape: hollow cylindrical sleeve
- OD (outer diameter) / ID (inner diameter): standard stock sizes + custom sizes; both leave machining allowance (typically 0.3~1 mm per side)
- Color: Black / Brown
- Tolerance: OD ±0.15~0.3 mm
- Length: standard 120 mm / 150 mm ; cut-to-length customization available
- Surface: smooth cured surface, free of bubbles, inclusions, and cracks (machining substrate; mirror finish not required)
- Raw material: FKM compound → extruded into hollow tube blank
- Cure: molding / oven post-cure (second stage), ensuring low compression set
- Cut to fixed-length semi-finished tubes
- End use: CNC lathe turning to produce O-rings, rod seals, hydraulic seals, and other precision seals
5. Applications
- Hydraulic & pneumatic seals (cylinder O-rings, U-cups, wiper seal blanks)
- Automotive: engine, gearbox, fuel system seals
- Petrochemical, pumps & valves, compressor high-temperature seals
- Construction & mining machinery, high-temperature oil-resistant seals
- Food & pharmaceutical: FDA-grade FKM tubes available
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