PTFE Ball Size & Weight Reference Table
Use the search box below to filter by mm, inch, weight, or tolerance. Weights are estimated for virgin PTFE (density ≈ 2.15 g/cm³).
| Metric Size (mm) | Imperial Size (Inch) | Standard Tolerance | Est. Weight (Grams/Piece) | Status |
|---|---|---|---|---|
| 6.00 mm | 1/4″ | ±0.05 mm | 0.24 g | Stocked / Ready |
| 8.00 mm | 5/16″ | ±0.05 mm | 0.58 g | Stocked / Ready |
| 9.52 mm | 3/8″ | ±0.05 mm | 0.97 g | Stocked / Ready |
| 10.00 mm | 13/32″ (approx) | ±0.05 mm | 1.13 g | Stocked / Ready |
| 12.70 mm | 1/2″ | ±0.08 mm | 2.30 g | Stocked / Ready |
| 15.87 mm | 5/8″ | ±0.08 mm | 4.50 g | Stocked / Ready |
| 19.05 mm | 3/4″ | ±0.08 mm | 7.78 g | Stocked / Ready |
| 22.22 mm | 7/8″ | ±0.10 mm | 12.35 g | Stocked / Ready |
| 25.40 mm | 1″ | ±0.10 mm | 18.45 g | Stocked / Ready |
| 31.75 mm | 1-1/4″ | ±0.10 mm | 36.00 g | Made-to-Order |
| 38.10 mm | 1-1/2″ | ±0.15 mm | 62.20 g | Made-to-Order |
| 44.45 mm | 1-3/4″ | ±0.15 mm | 98.80 g | Made-to-Order |
| 50.80 mm | 2″ | ±0.15 mm | 147.60 g | Made-to-Order |
| 63.50 mm | 2-1/2″ | ±0.18 mm | 288.20 g | Made-to-Order |
| 76.20 mm | 3″ | ±0.20 mm | 498.00 g | Made-to-Order |
| 100.00 mm | 4″ (approx) | ±0.25 mm | 1,125.70 g | Made-to-Order |
| 150.00 mm | 6″ (approx) | ±0.30 mm | 3,799.00 g | Custom Machined |
| 200.00 mm | 8″ (approx) | ±0.40 mm | 9,005.00 g | Custom Machined |
| 310.00 mm | 12.2″ (approx) | ±0.50 mm | 33,520.00 g | Heavy Custom |
* Non-standard diameters between 6 mm and 310 mm are fully customizable and can be machined on our precision CNC lathes to your print specifications.
Valve Seat and Ball Sizing Guidelines
For fluid flow and check valves, choosing the correct size ratio prevents seal failure and wedging issues.
Key Sizing Principles
In typical gravity-closed or spring-assisted ball check valves, the PTFE sphere sits directly on a metal or elastomeric seat. If the ball is too close to the orifice diameter, fluid pressure can force the ball into the seat, causing deformation (cold flow) and mechanical wedging.
Sizing Ratio: The nominal diameter of the ball should be 1.2 to 1.3 times the diameter of the circular seat orifice. For example, if your valve orifice has a diameter of 20 mm, a ball diameter of 24 mm to 26 mm is optimal.
Tolerance Selection: Standard tolerances (±0.05 mm to ±0.1 mm) are suitable for low-to-medium pressure systems. For high-pressure check valves or micro-metering applications, specify tighter tolerances (up to ±0.02 mm) to prevent micro-leakages around the sphere boundary.
Seat Seal Checklist
- Diameter Ratio: 1.25x Orifice Dia.
- Roundness: ≤ 0.05 mm limit.
- Surface: No turning lines.
- Chamber: 45-degree seat bevel.
How We Manufacture Custom Sizes
Hemsun Engg. Industries does not rely on third-party mold sets. Our in-house toolroom designs and prepares tooling in Gujarat, India.
Drawing Setup
Send us your drawings or a physical sample. We model the dimensions and configure machining profiles for the target sphere.
Mold Sizing
If a custom billet diameter is required, we turn custom compression molds to minimize material waste during subsequent machining stages.
Precision Turning
Specialized ball-turning mechanisms achieve high spherical roundness across both tiny 6 mm and huge 310 mm diameters.
Final QC
Each batch is measured for tolerance compliance using calibrated mechanical and laser measuring equipment.
Sizes & Sizing FAQ
Technical answers regarding sizing tolerances and customization capabilities.
Do you offer size charts for filled grades like Glass or Bronze-filled PTFE?
Yes. The dimensional size availability (6 mm to 310 mm) applies to all filled grades. However, because fillers affect thermal shrinkage, there may be slight density variations. Material certificates detail specific densities for filled grades.
Can you machine hollow PTFE balls?
We specialize in solid PTFE balls to ensure stability under chemical and physical pressure. For applications requiring hollow shapes or floating balls, contact our office to discuss wall thickness and diameter limits.
What is the difference between metric and imperial size availability?
We manufacture both metric (mm) and imperial (inch) sizes. Because we turn from solid billets, we can machine any decimal or fractional dimension. Standard sizes are stocked for rapid shipment.
What is the roundness tolerance on your stock sizes?
Our standard production achieves a roundness tolerance of within 0.05 mm to 0.1 mm, depending on the sphere diameter. Closer spherical tolerances can be discussed for high-precision seat applications.
Request Size Pricing
Looking for a standard size or a custom diameter? Contact us with your dimensions, material choice, and quantity for direct pricing.
- Response within 24 hours on business days
- MOQ flexible — samples and OEM volumes
- Engineering drawings accepted
- Export supply worldwide
- Metric and inch sizes from 6 mm to 310 mm
224/1, Zak-Vahelal Road, Dahegam
Gandhinagar, Gujarat 382305
India