Which injection grade of PBT are you looking for ?

We'll search our vast network of over 350 supply partners to find it for you - and at the best price.

Request a quote

Find the exact grade you require

Improve on your current price

Get the material you need faster


Polybutylene terephthalate

PBT is a strong, hard and also a stable engineering polymer widely used for electrical applications as an insulator. Part of the Polyester thermoplastics family

Call us today on 0141 952 1900 or click to email

”We are continually pleased with the standard of service offered to ourselves at Rediweld by the dedicated, qualified and efficient team at Hardies Polymers. Their company has developed and evolved with spectacular effect in recent years, being recognised by its equals and achieving several awards along the way. The company has integrity, strong traditional values and focuses on providing the utmost level of customer satisfaction at all times.

Hardie Polymers have been able to provide us with trade name polymers in lower volumes with competitive prices and realistic timescales, consistently for several years. Their team of dynamic, caring and professional staff are always there to help at the end of the phone.

Thank you for your continued efforts and support.”

Rediweld Technical Moulding, Alton, Hampshire

Physical Properties

  • High thermal stability
  • Great stiffness and hardness
  • Excellent for applications requiring anti-friction properties and abrasion resistance
  • Resistant to environmental stress cracking
  • Great dimensional stability
  • High strength
  • Low water absorption
  • Good weathering performance
  • High Continuous service temperature – up to 150°C
  • Excellent resistance to Creep

Chemical Properties

Resistant to oils, grease, alcohols, fuel, ethers, weak acids and alkaline solutions.

Not resistant to benzene, alkalis, strong acids, alkaline solutions and ketones.

Typical Applications

Automotive; there has been much growth in automotive electronics in recent years and PBT is a popular choice for many of these parts. Under bonnet parts, sensors, ignition systems and also exterior parts e.g. mirror housings.

Electrical and electronic parts such as bobbins, connectors, sockets, switches, circuit breakers, meter housings, appliance housings and light fittings

Can be used in yarn and fibre as a coating


PBT is a semi-crystalline polymer used mainly for injection moulding in engineering applications.

When PET was introduced its melt processing temperature was beyond the range of most injection moulding machines at that time and PBT was introduced as a thermoplastic with many of the properties of PET but had a lower processing temperature.

PBT can match the mechanical properties of PET, particularly when reinforced with glass fibre.

PBT is well suited to thin wall mouldings.

Some PBT grades have rapid crystallisation allowing fast cycle times.


Flame retardant and will extinguish outside the flame. Gives off a bright yellow/orange flame with a sweet smell.

Useful Data

Density –1.3 g/cm ³

Pre-Drying – 4 hours at 120°C in a dehumidifying hot air drier

Melt temperature – 250-260°C

Mould Temperature – 60-80°C

Shrinkage – Depends heavily on mould temperature. The hotter the mould, the higher the shrinkage 1.4-2.0 %. In the case of 30% glass filled PBT only 0.4-0.6%

Trade Names And Manufacturers

Crastin – DuPont

Pocan – Lanxess

Ultradur – BASF

Lupox – LG Chem

Valox – Sabic IP

Ramster – Polyram


Hardie Polymers can help source grades from all of the above manufacturers


Fibre forming Polyesters were first produced in 1932 by Carothers and Hill of DuPont, with the first PBT fibres produced 10 years later in 1942. PBT compounds for moulding were launched in the 1970’s and as demand grew with new applications being found, so the number of producers also steadily increased.

More about PBT

Articles by Dr Charlie Geddes

Is Thermoplastic Polyester your PET Subject?

What are Engineering Thermoplastics?

Our longstanding partnerships allow us to specialise in sourcing and compounding most grades of engineering polymers. All brand names listed are trademarks of the manufacturers and we are not an authorised distributor for these manufacturers. We only supply prime grades in original packaging with the manufacturers documentation.

® – Trademarks owned or used by the producers.
™ – Registered in the U.S. Patent and Trademark Office (status in the U.S. only, registration status in other geographies may be different)

We have supplied



Request a Quote

  • Our team are available from 8am-5pm and we always aim to get back to you the same day. If you would rather contact us immediately please join us on live chat
    or give us a call on 0141 952 1900.
  • This field is for validation purposes and should be left unchanged.