SFI 3.2A/5 racing suits
Two-layer Nomex® racing suits developed around SFI 3.2A/5, the rating many US series set as their minimum, for private-label brands and distributors.
What /5 means
SFI 3.2A grades a suit by the Thermal Protective Performance (TPP) of its material. The /5 grade requires a minimum TPP of 19 cal/cm². The rating applies to the material as built, whatever the number of layers, and underwear worn beneath the suit does not count towards it.
Cuircon's /5 construction is a 150 g/m² Nomex® outer shell over a 180 g/m² Nomex® inner layer, 330 g/m² in total, recorded at TPP 21.6 in our materials library.
What else the specification asks of the suit
Each layer passes a flammability test: an average of 2.0 seconds or less of after-flame and 6 inches or less of char length, with no melting or dripping. The sewing thread and the zipper are tested separately for heat resistance.
Zippers need metal teeth and fire-retardant tape, covered by fire-resistant material. Fire-resistant cuffs are required at the wrists and ankles, and stretch panels or gussets must reach the same minimum TPP as the rest of the suit.
What you can specify
One-piece or two-piece; panel layout and colours from our Nomex colour chart; stretch panels, radial or floating sleeves, pre-shaped arms and legs; collar and cuff styles; embroidery for sponsors and names; your labels and packaging.
Each choice is checked against the construction before quotation, so options that would affect the rating are flagged rather than discovered later.
Material: Nomex® 2-Layer Suit System
| Composition | 100% Nomex® meta-aramid, outer and inner layer |
|---|---|
| Weight | 330 g/m² total (150 g/m² outer + 180 g/m² inner) |
| Construction | Two-layer: woven outer shell over an inner layer |
| Fire resistance | Inherent — the protection is in the fibre and does not wash out |
| Recorded test data | TPP 21.6 |
From Cuircon's materials library. A material figure is not a garment certification. Ask for the test report behind any figure.
SFI 3.2A at a glance
| Issued by | SFI Foundation, Inc. |
|---|---|
| Current edition | Effective 26 June 2020 |
| Covers | Driver suits: one-piece suits, or jacket and pants |
| Graded by | TPP of the suit material: grades /1, /3, /5, /10, /15, /20, /25, /30 |
| Who certifies | The manufacturer, under a licence agreement with SFI. SFI does not certify or approve products. |
From the official specification. Read the full SFI 3.2A guide.
Products in this range
In development for certification
Designed around an SFI specification. Certification status, certifying manufacturer and labelling for your order are confirmed in the quotation.
Common questions
Is a two-layer suit automatically /5?
No. The grade depends on the tested TPP of the finished material system, not the number of layers. Our two-layer Nomex® construction is recorded at TPP 21.6 against the /5 minimum of 19.
Which series require /5?
Rules differ by series and class, and change between seasons. Check the current rulebook of the series the suit is for.
Related: Nomex® suits · Custom suits · SFI 3.2A/1 suits · SFI guide · Construction library · Who we serve