TUFNOL Grades 10G/40, 10G/41, 10G/42 and 10G/44
Epoxy Glass Fabric laminate
Glass fibre/epoxide resin laminated plastic
(SRBGF - Synthetic Resin Bonded Glass Fabric)

Top quality materials for mechanical and electrical applications.
The TUFNOL range of high quality epoxy resin bonded glass fabric laminates offer very high mechanical strength and low moisture absorption, combined with excellent electrical properties, under both dry and humid conditions. They are rigid materials with good dimensional stability and good resistance to a wide range of working environments.
Four standard grades are available:
- TUFNOL Grade 10G/40 – The most widely used grade, suitable for continuous use at temperatures up to approximately 130ºC. (Class B).
- TUFNOL Grade 10G/41 – Similar to 10G/40, but with comtrolled flammability
- TUFNOL Grade 10G/42 – Made with an epoxy resin which offers increased mechanical strength at higher temperatures. Suitable for uses up to 155 ºC (Class F).
- TUFNOL Grade 10G/44 – Similar to Grade 10G/42, but with improved retention of strength after heat ageing.

What are TUFNOL epoxy glass fabric materials used for?
These high performance materials are used for a very wide variety of applications where high strength, rigidity dimensional stability and electrical performance are required. Applications such as insulation in large turbine generators, components for cryogenic superconducting magnets, high strength bolt insulation in structures, jigs for electro-chemical machining and structural insulation for high performance electronic equipment, these are typical of the many uses to which this material is put. However, due to the abrasive nature of the high glass fibre content, epoxy glass grades are not normally selected for wearing or bearing applications.
TYPES AVAILABLE
|
Sheets
|
Rods
|
Tubes
|
Other sections |
Grade 10G/40 – Natural colour |
Yes |
Yes |
No |
No |
Grade 10G/41 – Natural colour |
Yes |
No |
No |
No |
Grade 10G/42 – Natural colour |
Yes |
No |
No |
No |
Grade 10G/44 - Natural colour |
Yes |
No |
No |
No |
|
|
|
|
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Click here for TUFNOL Epoxy Glass Grade STANDARD SIZES
SPECIFICATIONS for TUFNOL Epoxy Glass Fabric Laminates
BRITISH STANDARDS |
Current Standards |
Recent Standards (now obsolete) |
Grade 10G/40 Sheet |
BS EN 60893-3-2 Type EP GC 201 |
BS 3953 Type EP-3 |
Grade 10G/40
Round Rod (Rolled & moulded) |
BS EN 61212-3-3 Type EP GC 41 & 42 |
BS 6128 Part 2 Type EP GC 21 |
Grade 10G/41 Sheet |
BS EN 60893-3-2 Type EP GC 202 |
BS 3953 Type EP-4 |
Grade 10G/42 Sheet |
BS EN 60893-3-2 Type EP GC 203 |
BS 3953 Type EP-5 |
Grade 10G/44 Sheet |
BS EN 60893-3-2 Type EP GC 203
& BS 3953 Type EP-7 |
(BS 3953 will shortly become obsolete.) |
|
|
|
NEMA* |
|
|
Grade 10G/40 Sheet & Rod |
NEMA LI-1-1983 Type G10 |
|
Grade 10G/41 Sheet |
NEMA LI-1-1983 Type FR4 |
|
Grade 10G/42 Sheet |
NEMA LI-1-1983 Type G11 |
|
Grade 10G/44 Sheet |
NEMA LI-1-1983 Type G11 |
|
*Testing and certification to these standards is subject to special enquiry. Standard quality testing is to British Standards.
PHYSICAL PROPERTIES
TUFNOL Epoxy Glass Sheet
PROPERTY |
Grade 10G/40
TYPICAL RESULT |
Grade 10G/41
TYPICAL RESULT |
Grade 10G/42
TYPICAL RESULT |
Grade 10G/44
TYPICAL RESULT |
UNITS |
Cross breaking strength |
490 |
470 |
490 |
490 |
MPa |
Cross breaking strength at 150ºC
– (after 1 hour at 150ºC) |
- |
- |
350 |
360 |
|
Cross breaking strength at 150ºC
– (after 100 hours at 200ºC) |
- |
- |
- |
250 |
|
Impact strength, notched, Charpy |
60 |
60 |
60 |
60 |
kJ/m2 |
Compressive strength, flatwise |
415 |
415 |
415 |
415 |
MPa |
Compressive strength, edgewise |
300 |
300 |
300 |
300 |
MPa |
Tensile strength |
355 |
- |
- |
- |
MPa |
Young's modulus |
17.7 |
- |
- |
- |
GPa |
Water Absorption |
|
|
|
|
|
- 1.6mm thk. |
5 |
5 |
5 |
5 |
mg |
- 3mm thk. |
7 |
7 |
7 |
7 |
mg |
- 6mm thk. |
10 |
10 |
10 |
10 |
mg |
- 12mm thk. |
15 |
15 |
15 |
15 |
mg |
Electric strength, flatwise in oil at 90ºC |
|
|
|
|
|
- 1.6mm thk. |
17 |
17 |
17 |
17 |
MV/m |
- 3mm thk. |
15 |
15 |
15 |
15 |
MV/m |
- 6mm thk. |
12 |
12 |
12 |
12 |
MV/m |
Electric strength, edgewise in oil at 90ºC |
75 |
75 |
70 |
70 |
kV |
Insulation resistance after immersion in water |
1x1011 |
5x1010 |
5x1010 |
5x1010 |
ohms |
Relative density |
1.90 |
1.95 |
1.90 |
1.90 |
- |
Loss tangent at 1 MHz |
0.017 |
0.017 |
0.017 |
0.017 |
|
Permittivity at 1 MHz |
5.0 |
4.9 |
5.2 |
5.2 |
|
Comparative tracking index |
285 |
260 |
290 |
290 |
|
Maximum working temperature** |
|
|
|
|
|
- continuous |
130 |
130 |
140 |
140 |
ºC |
- intermittent |
150 |
150 |
155 |
155 |
ºC |
Thermal classification |
Class B |
Class B |
Class F |
Class F |
- |
Thermal conductivity through laminae |
0.42 |
0.42 |
0.45 |
0.45 |
W/(mK) |
Thermal expansion in plane of laminae |
1.1 |
1.0 |
1.2 |
1.2 |
x 10-5/K |
Test methods as BS EN 60893-2, where applicable.
TUFNOL Grade 10G/40 Round Rod
PROPERTY |
Grade 10G/40
TYPICAL RESULT |
UNITS |
Flexural strength |
600 |
MPa |
Water absorption |
0.5 |
mg/cm2 |
Insulation resistance after immersion in water |
5x109 |
ohms |
Axial electric strength in oil at 90ºC |
70 |
kV |
Relative density |
1.90 |
- |
Test methods as BS EN 61212-2, where applicable.
**Users of highly stressed components at temperatures approaching the maximum are recommended to seek further advice from Tufnol Composites Ltd.