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PTFE-Bronze40 BZ-GR

Additive grade

Choose for high sliding speed and water/steam service where a lower friction coefficient than plain bronze-filled is needed.

High cost $$$$

Values for the BZ-GR condition

Other PTFE-Bronze40 grades and fills

PTFE-Bronze40 is listed in 4 conditions; see the grade overview at PTFE-Bronze40.

Compare all 4 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
BZ-GRThis page
PTFE + bronze + graphite (typ. 40% bronze / 5% graphite)
Choose for high sliding speed and water/steam service where a lower friction coefficient than plain bronze-filled is needed.101312063 Shore D
PTFE + 55% bronze + 5% molybdenum disulphide
Use where dry-running start-up friction and stick-slip must be minimised on steel counterfaces.10129068 Shore D
BZ40Default
PTFE + 40 wt% bronze
Standard bronze-filled bearing/seal compound: best balance of load capacity, wear life and machinability.111615065 Shore D
PTFE + 60 wt% bronze
Pick for maximum PV, minimum creep and best heat removal in hydraulic piston rings and heavy-duty bushings.—1310068 Shore D

What is PTFE-Bronze40 BZ-GR?

PTFE-Bronze40 BZ-GR is PTFE-Bronze40 in the BZ-GR grade — choose for high sliding speed and water/steam service where a lower friction coefficient than plain bronze-filled is needed. PTFE-Bronze40 BZ-GR has a yield strength of 10 MPa (1.38 ksi) and a tensile strength of 13 MPa (1.89 ksi) — weaker than 92% of polymer grades. Elongation at break is 120% and the elastic modulus is 1.1 GPa (0.152 Msi). PTFE-Bronze40 BZ-GR has a density of 2.95 g/cm³ (0.107 lb/in³), heavier than 100% of polymer grades. Its glass-transition temperature is -97°C (-143 °F). BZ40 is the default condition FabDigit quotes; BZ-GR is available on request or by drawing note.

Advantages

  • Conducts heat well — 0.5 W/m·K (0.289 BTU/hr·ft·°F), better than 98% of polymer grades
  • Good UV / weathering resistance — 95/100, better than 95% of polymer grades
  • High service temperature — 250°C (482 °F), better than 94% of polymer grades
  • Low moisture uptake — 0.04%, better than 86% of polymer grades
  • Easy to machine — 72/100, better than 76% of polymer grades

Limitations

  • Heavy — 2.95 g/cm³ (0.107 lb/in³), worse than 100% of polymer grades
  • Low strength — 10 MPa (1.38 ksi), worse than 92% of polymer grades
  • Difficult to weld — 5/100, worse than 89% of polymer grades
  • High mold shrinkage — 2.3%, worse than 89% of polymer grades
  • Hard to polish — 30/100, worse than 82% of polymer grades

PTFE-Bronze40 BZ-GR properties

Typical room-temperature values for PTFE-Bronze40 BZ-GR; 26 are specific to this condition. Other listed values are PTFE-Bronze40 reference data and may not represent this condition. Bars are the position among polymer grades.

Physical4

PTFE-Bronze40 BZ-GR has a density of 2.95 g/cm³ (0.107 lb/in³), heavier than 100% of polymer grades. Its glass-transition temperature is -97°C (-143 °F).

Density2.95 g/cm³0.11 lb/in³
Melting Temperature (Tm)327°C621 °F
Glass Transition (Tg)-97°C-143 °F
Water Absorption (24 h)0.04%

Mechanical15

PTFE-Bronze40 BZ-GR has a yield strength of 10 MPa (1.38 ksi) and a tensile strength of 13 MPa (1.89 ksi) — weaker than 92% of polymer grades. Elongation at break is 120% and the elastic modulus is 1.1 GPa (0.152 Msi).

Elastic (Young's) Modulus1.1 GPa0.15 Msi
Poisson's Ratio0.42
Tensile Strength (Ultimate)13 MPa1.9 ksi
Yield Strength (0.2% offset)10 MPa1.4 ksi
Elongation at Break120%
Compressive Strength21 MPa3 ksi
Compressive Modulus1.2 GPa0.17 Msi
Flexural Strength13 MPa1.9 ksi
Flexural Modulus1.2 GPa0.17 Msi
Shear Strength11 MPa1.6 ksi
Fracture Toughness (K_IC)1.8 MPa·√m1.6 ksi·√in
Izod Impact, Notched55 J/m1 ft·lbf/in
Hardness, Shore A97 Shore A
Hardness, Shore D63 Shore D
Hardness, Rockwell R66 HRR

Thermal10

PTFE-Bronze40 BZ-GR is rated for continuous service to 250°C (482 °F). It conducts heat at 0.5 W/m·K (0.289 BTU/hr·ft·°F), better than 98% of polymer grades. Thermal expansion is 88 µm/m·K (48.9 µin/in·°F).

Thermal Conductivity0.5 W/m·K0.29 BTU/hr·ft·°F
Specific Heat Capacity760 J/kg·K0.18 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)88 µm/m·K48.9 µin/in·°F
Max Service Temperature (continuous)250°C482 °F
Min Service Temperature-190°C-310 °F
Heat Deflection Temp. @ 0.45 MPa140°C284 °F
Heat Deflection Temp. @ 1.8 MPa75°C167 °F
Flammability (UL 94)V-0
Limiting Oxygen Index95%
Max Service Temperature (short-term)300°C572 °F

Electrical2

PTFE-Bronze40 BZ-GR has an electrical resistivity of 1 Ω·m.

Electrical Resistivity1 Ω·m3.94×10⁷ µΩ·in
Volume Resistivity1,000,000 Ω·cm

Chemical & Environmental3

Corrosion resistance is very good (72/100), worse than 70% of polymer grades. UV resistance is excellent.

Corrosion ResistanceVery good72/100
UV / Weathering ResistanceExcellent95/100
Chemical Resistance SummaryPTFE matrix is near-universally inert, but exposed bronze particles are attacked by acids, strong oxidizers, ammonia/amines, chlorinated water and seawater; avoid where the filler can be leached — use glass- or carbon-filled PTFE instead.

Sustainability3

Producing a kilogram of PTFE-Bronze40 BZ-GR takes about 145 MJ of energy and emits 7 kg of CO₂ — more than 83% of polymer grades. Typical recycled content is 0%.

Embodied Energy (primary production)145 MJ/kg62,339 BTU/lb
Embodied Carbon (primary production)7 kg CO₂/kg
Typical Recycled Content0%

Manufacturability6

PTFE-Bronze40 BZ-GR's machinability is very good (72/100, better than 76% of polymer grades); weldability not recommended (5/100); formability poor (15/100).

MachinabilityVery good72/100
WeldabilityNot recommended5/100
Formability (cold)Poor15/100
PolishabilityPoor30/100
Mold Shrinkage2.3%
Processing Melt Temperature (typ.)375°C707 °F

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with PTFE-Bronze40 BZ-GR

Is PTFE-Bronze40 easy to machine?

Turns and mills easily with very sharp, positive-rake carbide or PCD tools; the bronze filler is abrasive so HSS dulls fast — use high speed, light cuts, and support thin walls against cold flow and thermal growth.

Can PTFE-Bronze40 be welded?

Not weldable or solvent-bondable; joints must be mechanical (clamped, retained rings) or use etched-surface adhesive bonding with sodium-naphthalene/plasma treatment.

Can PTFE-Bronze40 be formed, bent or molded?

Not melt-processable — cold-pressed and free-sintered at ~370–380 °C with slow cooling; ram extrusion is used for rod/tube, and rings are skived or moulded to near-net shape.

What surface finishes work on PTFE-Bronze40?

No plating or painting; finish by fine turning/burnishing, and run in against a hard (≥45 HRC) counterface polished to Ra 0.2–0.4 µm to build the transfer film.

PTFE-Bronze40 chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
bronze powder (CuSn10 / CuSn10Zn)atomised or irregular bronze; ~15 vol% of the compound38 – 4240
PTFE (polytetrafluoroethylene)suspension-polymerised moulding powder≥ 58 (balance)—

PTFE-Bronze40 BZ-GR — frequently asked

What is PTFE-Bronze40 BZ-GR used for?

PTFE-Bronze40 BZ-GR is typically used for high-load thrust washers and bearings, hydraulic rod/piston seals, wear rings in hydraulic cylinders and guide rings. In short: highest load-capacity PTFE; most thermally conductive PTFE; abrasive; needs carbide tooling.

What is the yield strength of PTFE-Bronze40 BZ-GR?

PTFE-Bronze40 BZ-GR has a typical yield strength of 10 MPa (1.38 ksi) and a tensile strength of 13 MPa (1.89 ksi) — weaker than 92% of polymer grades. Strength varies by condition: see the 4 listed tempers.

Is PTFE-Bronze40 BZ-GR easy to machine?

Yes — machinability is rated very good (72/100, better than 76% of polymer grades). Turns and mills easily with very sharp, positive-rake carbide or PCD tools; the bronze filler is abrasive so HSS dulls fast — use high speed, light cuts, and support thin walls against cold flow and thermal growth.

Can PTFE-Bronze40 BZ-GR be welded?

Not readily — weldability is rated not recommended (5/100). Not weldable or solvent-bondable; joints must be mechanical (clamped, retained rings) or use etched-surface adhesive bonding with sodium-naphthalene/plasma treatment.

What surface finishes work on PTFE-Bronze40 BZ-GR?

No plating or painting; finish by fine turning/burnishing, and run in against a hard (≥45 HRC) counterface polished to Ra 0.2–0.4 µm to build the transfer film.

Can PTFE-Bronze40 BZ-GR be formed, bent or molded?

Not melt-processable — cold-pressed and free-sintered at ~370–380 °C with slow cooling; ram extrusion is used for rod/tube, and rings are skived or moulded to near-net shape.

What is the maximum service temperature of PTFE-Bronze40 BZ-GR?

PTFE-Bronze40 BZ-GR is rated for continuous use to about 250°C (482 °F), and briefly to 300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between PTFE-Bronze40 BZ40 and PTFE-Bronze40 BZ-GR?

BZ40 is the default condition — standard bronze-filled bearing/seal compound: best balance of load capacity, wear life and machinability. BZ-GR: choose for high sliding speed and water/steam service where a lower friction coefficient than plain bronze-filled is needed. Yield strength is 11 MPa in BZ40 versus 10 MPa in BZ-GR.

Sources

  1. ASTM D4745 — Filled Compounds of PTFE Molding and Extrusion Materials — ASTM International (2021)
  2. ASTM D4894 / D4895 — PTFE Molding and Extrusion Materials — ASTM International (2022)
  3. TECAFLON PTFE filled compounds (bronze, glass, carbon) — Ensinger (2023)
  4. Filled PTFE compound property tables — Fluorocarbon / Zeus Industrial Products (2022)
  5. Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.