Spelsberg uses different materials in order to meet the different requirements and demands of our customers in on-site installation. We look for high quality in the materials that are used.

Our long-term experience working with various plastics helps us in the process. We are capable of choosing the best material for the best products, depending on the application. We offer two different standard qualities at Spelsberg:

Standard quality primary for indoors:

  • Polystyrene: Abox, RK /RKA, TK-PS
  • ABS (acrylonitrile butadiene styrene): TG-ABS
  • Thermoset: WK connection boxes, WKE fire protection boxes

Industrial quality for high material requirements:

  • Polycarbonate: TG-PC, AK
  • Glass-fibre reinforced polycarbonate: Abox-i, STV/STG, AK, GTi system, AKi, TK-PC, ZKi, ZVi, SVi
  • Aluminium: AL, ALR, TK AL

An overview of the materials used at Spelsberg and their properties is available here:

o = resistant
ø = partially resistant
x = not resistant   
MaterialUse in the products

Weak acids

Strong acids

Weak bases

Strong bases




Mineral oil


Ammonia, liquid

Ammonia, gaseous

Vegetable fats

Animal fats


Free of heavy metals,
PVC and silicone

Flammability acc. to
DIN EN 60695
(VDE 0471) / UL94

Polystyrene, shock-proofAK compact-system,
Abox, RK / RKA, TK-PS
oøoooxxoxon.a.oxyesyes650°C / HB
ABS (Acrylnitril-Brutadien-Styrol)TG-ABSoøoooxxooon.a.oxyesyes650°C / HB
Abox-i, STV/STG, AK, GTi-System, AKi, TK-PC, ZKi, ZVi, SVioxxxoøxoøxooøyesyes960°C/ V-2 (5VA*)
PolycarbonateTG-PC, AKoxxxoøxoøxooøyesyes960°C/ V-2 (5VA*)
Polycarbonate, transparentHinged lid AK smallscale distributor and STV, lid AKL, AKi, GTi, TK-PCoxxxøøxoøxoooyesyes850°C/ V-2
PolyethyleneAttachment bushes, twist nipple, Red Range (bottom section)oooooøxoxon.a.ooyesyes650°C / HB
PolypropyleneHW-series, KD-channelsockets, HPoooooøøoxon.a.ooneinyes960°C/ V-2 
Polypropylene copolymerIBT / IBTronic, Red Range (lid)oooooøøøøon.a.ooyesyes650°C / HB
PolyurethaneAll types with foamed lid sealøøøøøøøxøøoooyesyes650°C / ---
AluminiumAL, ALR, TK ALoøoooooooon.a.ooyesyes---
DuroplasticWK junction boxes, WKE fireproof junction boxesøøøøoooooon.a.ooyesyes960°C/ V-0
DuroplasticWK series integrated terminal block except for 4 mm²xxøxoooooon.a.ooyesyes960°C/ V-0
Polyamide 6, glass fibre-reinforcedScrew fittings to IP 68, Cover screwsxxooooøooooooyesyes750°C/ HB /V-2 
Thermoplastic elastomerDouble-membrane glands, inlet membranes (Abox 025 / 040, 2K-12)oøoøoøøøøøoooyesyes750°C/ HB