PBT (poly­buty­lene tereph­tha­late) [Hydex® 4101, Valox®]


  • Man­u­fac­tured from poly­buty­lene tereph­tha­late poly­ester (PBT-P) resin.
  • Semi-crystalline ther­mo­plas­tic
  • Chemical-, water– and steam-resistant
  • Impact-resistant
  • Low coef­fi­cient of fric­tion and wear
  • Does not need lubrication
  • Avail­able in FDA-approved white and black
  • Replaces brass, alu­minum, steel and acetal

Com­mon uses

  • Food pis­ton pumps
  • Valve and valve bodies
  • Feeder blocks
  • Tim­ing screws
  • Gears
  • Cams
  • Bush­ings
  • Bear­ings
  • Wear strips
  • Fuel pump components
  • Fuel sys­tem con­nec­tors and rotors


Mate­r­ial Specifications

ASTM or UL test Prop­erty Value
D792 Den­sity (lb/in3)/(g/cm3) 0.047 (1.31)
D570 Water absorp­tion, 24 hrs (%) 0.07
D638 Ten­sile strength (psi) 9,400
D638 Ten­sile elon­ga­tion at break (%) 50
D638 Ten­sile mod­u­lus (psi) 425,000
D790 Flex­ural strength (psi) 11,600
D790 Flex­ural mod­u­lus (psi) 420,000
D695 Com­pres­sive strength (psi) 11,000
D695 Com­pres­sive mod­u­lus (psi) -
D785 Hard­ness, Rockwell 120
D256 Izod notched impact (ft-lb/in) 0.7
D3418 Melt­ing temp (F°/C°) 420/215
D696 Coef­fi­cient of lin­ear ther­mal
expan­sion (x 10–5 in./in./°F)
D648 Heat deflec­tion temp (F°/C°) at 264 psi 200/93
- Max oper­at­ing temp (F°/C°) 221/105
C177 Ther­mal con­duc­tiv­ity
UL94 Flam­ma­bil­ity rating H-B
D150 Dielec­tric con­stant at 60 Hz 3.3
D150 Dis­si­pa­tion fac­tor at 60 Hz 0.002
D149 Dielec­tric strength (V/mil)
short time, ⅛” thick
D257 Vol­ume resis­tiv­ity (ohm/cm) at 50% RH 4.5 x 1016

These are typ­i­cal val­ues for ref­er­ence and com­par­i­son only. They should not be used as a basis for design spec­i­fi­ca­tions or qual­ity con­trol. Con­tact us for the man­u­fac­tur­ers’ com­plete mate­r­ial prop­erty datasheets. All val­ues were taken at 73°F (23°C) unless oth­er­wise noted.

Don’t see what you’re look­ing for? Call us at 800–423-2769 or email us at tom@crownplasticsinc.com.

*Hydex® is reg­is­tered trade­mark of Ensinger.