Product Information
Jul 2020
Ultradur® B 4300 G4
Polybutylene Terephthalate (PBT)

Product Description
Ultradur B 4300 G4 is an easy flowing injection molding PBT with 20% glass fiber reinforcement for rigid, tough, and dimensionally stable parts.

Typical applications include car door handles, housings for small electric motors, headlight retainers and drum controllers.

PHYSICAL ISO Test Method Property Value
Density, g/cm³ 1183 1.45
Viscosity Number, cm³/g 1628 109
Mold Shrinkage, parallel, % 294-4 0.43
Mold Shrinkage, normal, % 294-4 1.16
Moisture, % 62  
    (50% RH) 0.2
    (Saturation) 0.4
RHEOLOGICAL ISO Test Method Property Value
Melt Volume Rate (250 C/2.16 Kg), cc/10min. 1133 14
MECHANICAL ISO Test Method Property Value
Tensile Modulus, MPa 527  
    23C 7,100
Tensile stress at break, MPa 527  
    -40C 173
    23C 120
Tensile strain at break, % 527  
    -40C 2.9
    23C 3.0
Flexural Modulus, MPa 178  
    23C 6,300
IMPACT ISO Test Method Property Value
Charpy Notched, kJ/m2 179  
    23C 8
Charpy Unnotched, kJ/m2 179  
   -30C 54
    23C 58
THERMAL ISO Test Method Property Value
Melting Point, C 3146 223
HDT A, C 75 205
HDT B, C 75 220
Coef. of Linear Thermal Expansion, Parallel, mm/mm C 0.35 X10-4
ELECTRICAL ISO Test Method Property Value
Comparative Tracking Index IEC 60112 300
Volume Resistivity (Ohm-m) IEC 60093 >1E13
Surface Resistivity (Ohm) IEC 60093 1E13
Dielectric Constant (100 Hz) IEC 60250 3.7
Dielectric Constant (1 MHz) IEC 60250 3.7
Dissipation Factor (100 Hz), E-4 IEC 60250 12
Dissipation Factor (1 MHz), E-4 IEC 60250 150
UL RATINGS UL Test Method Property Value
Relative Temperature Index, 0.75mm UL746B  
    Mechanical w/o Impact, C 130
    Mechanical w/ Impact, C 125
    Electrical, C 130
Flammability Rating, 1.5mm UL94 HB
Relative Temperature Index, 1.5mm UL746B  
    Mechanical w/o Impact, C 130
    Mechanical w/ Impact, C 125
    Electrical, C 130
Flammability Rating, 3.0mm UL94 HB
Relative Temperature Index, 3.0mm UL746B  
    Mechanical w/o Impact, C 140
    Mechanical w/ Impact, C 125
    Electrical, C 130

Processing Guidelines
Material Handling
Max. Water content: 0.04%
To ensure optimum part performance, this product must be dried prior to molding and maintained at a moisture level of less than 0.04%. Dehumidifying or desiccant dryers operating at 100-120C (212-248F) for 4 hours drying time are recommended. Further information concerning safe handling procedures can be obtained from the Safety Data Sheet. Alternatively, please contact your BASF representative.

Typical Profile
Melt Temperature 250-270C (482-518F)
Mold Temperature 60-100C (140-212F)
Injection and Packing Pressure 35-125 bar (500-1500 psi)

Mold Temperatures
This product can be processed over mold temperatures of 60-100C (140-212F); however, for optimizing surface appearance, dimensional stability and part performance, mold surface temperatures of at least 80C (176F) are preferred.

Injection pressure controls the filling of the part and should be applied for 90% of ram travel. Packing pressure affects the final part and can be used effectively in controlling sink marks and shrinkage. It should be applied and maintained until the gate area is completely frozen off.

Back pressure can be utilized to provide uniform melt consistency and reduce trapped air and gas. A maximum of 10 bar (145 psi) is recommended due to the risk of excessive shear.

Fill Rate
Fast fill rates are recommended to ensure uniform melt delivery to the cavity and prevent premature freezing. Surface appearance is directly affected by injection rate.

Although all statements and information in this publication are believed to be accurate and reliable, they are presented gratis and for guidance only, and risks and liability for results obtained by use of the products or application of the suggestions described are assumed by the user. NO WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE MADE REGARDING PRODUCTS DESCRIBED OR DESIGNS, DATA OR INFORMATION SET FORTH. Statements or suggestions concerning possible use of the products are made without representation or warranty that any such use is free of patent infringement and are not recommendations to infringe any patent. The user should not assume that toxicity data and safety measures are indicated or that other measures may not be required.

  BASF Corporation
Engineering Plastics
1609 Biddle Avenue
Wyandotte, MI 48192
General Information: 800-BC-RESIN
Technical Assistance: 800-527-TECH (734-324-5150)
Web address: