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1. Tufnol Whale sheet:
- Tufnol Whale sheet (mechanical) is also known as SRBF
- It is the grade designed for engineering purposes
- It is perfect for wear resistant componants such as bearings, bushes, gears, washers, slideways and above waterline marine use
- Dimensionally, it is very stable
- Can be run dry or lubricated with water, oils or grease.
2. Tufnol Kite sheet:
- Tufnol Kite sheet (High electrical) is an excellent composite plastic sometimes known as bakelite or SRBP that has a distinctive dark brown colour
- Tufnol Kite grade is the high voltage electrical insulator for circuit boards, terminal boards, washers, spacers, covers and protectors
- It has a very rigid material that has low moisture absorbtion
- It is easily machined
3. 1P/13 Tufnol sheet:
- 1P/13 Tufnol sheet is the standard low cost grade suitable for jigs, fixtures, base plates, spacers and low voltage insulation
- Tufnol 1P/13 is similar but has a higher mechanical and impact strength than Kite grade and is easily machined
- Due to its good all round properties Tufnol IP/13 has become very popular for less demanding mechanical and insulation duties
Manufacturers produce engineering plastics that are slightly oversize in either diameter and/or thickness. This oversize tolerance, which is listed in the tables below, is provided to assist customers to produce very accurate items within the size shown and remove any minor surface imperfections
Tufnol Sheet tolerances:
The table below shows the dimensional tolerances permitted on Tufnol laminated sheets in the 'as moulded' condition. These tolerances based on the relevant British Standards or BS EN Standards for each Tufnol grade.
All sizes and tolerances quoted are in millimetres
Tolerances specified are PLUS AND MINUS from the nominal size. For example, reading from the table below, a Paper Based Tufnol sheet of 3.0mm nominal thickness may vary in thickness from 2.75mm to 3.25mm.
Notes: Due to manufacturing process, sheet thickness can vary at any point accross the entire sheet area and the below tolerances apply to any point over the entire sheet surface.
| Nominal Thickness |
Tolerance in mm, + and - about nominal thickness |
| Tufnol Grade --> |
1P/13 |
Kite |
Whale |
| 0.4 |
0.07 |
0.07 |
- |
| 0.5 |
0.08 |
0.08 |
0.13 |
| 0.6 |
0.09 |
0.09 |
0.14 |
| 0.8 |
0.10 |
0.10 |
0.15 |
| 1.0 |
0.12 |
0.12 |
0.16 |
| 1.2 |
0.14 |
0.14 |
0.17 |
| 1.6 |
0.16 |
0.16 |
0.19 |
| 2.0 |
0.19 |
0.19 |
0.21 |
| 2.5 |
0.22 |
0.22 |
0.24 |
| 3.0 |
0.25 |
0.25 |
0.26 |
| 4.0 |
0.30 |
0.30 |
0.32 |
| 5.0 |
0.34 |
0.34 |
0.36 |
| 6.0 |
0.37 |
0.37 |
0.40 |
| 8.0 |
0.47 |
0.47 |
0.49 |
| 10.0 |
0.55 |
0.55 |
0.56 |
| 12.0 |
0.62 |
0.62 |
0.64 |
| 14.0 |
0.69 |
0.69 |
0.70 |
| 16.0 |
0.75 |
0.75 |
0.76 |
| 20.0 |
0.86 |
0.86 |
0.87 |
| 25.0 |
1.00 |
1.00 |
1.02 |
| 30.0 |
1.15 |
1.12 |
1.12 |
| 35.0 |
1.25 |
1.25 |
1.12 |
| 40.0 |
1.35 |
1.35 |
1.35 |
| 45.0 |
1.45 |
1.45 |
1.45 |
| 50.0 |
1.55 |
1.55 |
1.55 |
Flatness Tolerances of Tufnol Sheet:
The below table is the maximum deviation from flat over a distance of 1000mm using a straight edge.
| Sheet Thickness |
Variation |
| 1.6mm to 3mm |
up to 18mm |
| 3mm to 6mm |
up to 10mm |
| 6mm to 8mm |
up to 8mm |
| over 8mm |
up to 6mm |
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