Galvanized Bundy Tube Hot-Dip Galvanized Precision Bundy Tube For Automobile Brake
Material
Galvanized Bundy tube is a double-wall, copper-brazed low-carbon precision steel tube designed for automotive fluid line service. In brake-line applications, the core value of this product is the combination of a compact double-wall structure, stable forming behavior, and protected outer surface for corrosion resistance. SAE J527 and ASTM A254 both describe this double-wall copper-brazed tubing family for automotive and similar line applications, while ISO 4038 covers metallic pipes used in hydraulic braking systems for road vehicles.
Specifications
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Product type: Double-wall copper-brazed precision steel tube
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Surface condition: Galvanized outer protection for corrosion resistance
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Typical automotive brake-pipe outside diameters: 4.75 mm, 6 mm, 8 mm, and 10 mm
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Processing capability: Suitable for bending, flaring, beading, forming, and brazing
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Typical technical route: ASTM A254 / SAE J527 / ISO 4038 / DIN 74234 / JASO M101 / GOST 11249 / GB/T 34020.2
Main Features
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Double-wall construction for higher structural reliability in brake-line service
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Excellent bendability and flare consistency for vehicle pipeline forming
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Corrosion-protected outer surface for improved service life
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Precision dimensional control suitable for automotive line routing
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Compatible with mainstream international brake-tube specification frameworks
Our Advantages
1. Designed around real brake-line forming requirements
Many buyers worry that low-cost tubing may split during bending or flaring. This product family is built on standards specifically intended for bending, flaring, beading, forming, and brazing, rather than on generic pipe language. That makes it a more credible choice for automotive brake lines and similar safety-related fluid routing.
2. Better corrosion-risk control for road service
Brake pipes are exposed to moisture, debris, and, in many markets, road salt. ISO 4038 requires the outer surface of brake pipes to be protected against corrosion and to withstand a neutral salt spray test for at least 96 hours. For procurement, this means buyers can define coating performance more clearly instead of relying on a vague “galvanized” description alone.
3. Easier multi-market sourcing and technical alignment
A major purchasing concern is whether one tube platform can support different export markets. This product family can be aligned with ASTM/SAE practice in North America, DIN/ISO brake-pipe references in Europe, JASO in Japan, GOST in CIS markets, and GB/T automotive double-wall tube practice in China. That helps OEM, aftermarket, and distributor buyers reduce approval friction across regions.
Chemical Composition
| Grade |
Standard / Reference Basis |
C (%) |
Si (%) |
Mn (%) |
P (%) |
S (%) |
Other Key Limits |
| BHG1 |
Q/BQB 494-2023 |
≤0.008 |
≤0.03 |
≤0.30 |
≤0.020 |
≤0.020 |
Alt ≥0.015 |
| BHG2 |
Q/BQB 494-2023 |
0.015-0.06 |
≤0.03 |
≤0.30 |
≤0.030 |
≤0.030 |
Alt ≥0.015 |
| ST12 |
DIN 1623 commercial reference |
≤0.10 |
— |
≤0.50 |
≤0.035 |
≤0.035 |
Alt ≥0.020 |
| SPCC |
JIS G 3141 |
≤0.15 |
— |
≤0.60 |
≤0.100 |
≤0.050 |
Alloying additions may be added as required |
| 10# |
GB/T 699-2015 |
0.07-0.13 |
0.17-0.37 |
0.35-0.65 |
≤0.035 |
≤0.035 |
Cr ≤0.15, Ni ≤0.30, Cu ≤0.25 |
Mechanical Properties
| Grade |
Condition / Basis |
Yield Strength (MPa) |
Tensile Strength (MPa) |
Elongation (%) |
Remarks |
| BHG1 |
Q/BQB 494-2023 |
130-230 |
≥260 |
≥39 |
Strip reference for welded pipe use |
| BHG2 |
Q/BQB 494-2023 |
180-280 |
≥275 |
≥34 |
Strip reference for double-wall welded pipe use |
| ST12 |
DIN 1623 commercial reference |
≤280 |
270-410 |
≥28 |
Common cold-rolled reference for simple forming |
| SPCC |
JIS G 3141 reference |
— |
Usually not guaranteed unless ordered as SPCCT |
Usually not guaranteed unless ordered as SPCCT |
SPCC is commercial quality |
| SPCCT basis for SPCC guarantee |
JIS G 3141 |
— |
≥270 |
≥28 to ≥39 depending thickness |
Mechanical guarantee route for SPCC when requested |
| 10# |
GB/T 699-2015, normalized reference |
≥205 |
≥335 |
≥31 |
GB carbon steel reference, not finished brake-tube acceptance |
Applicable Standards
| Standard System |
Reference |
Brief Description |
| ASTM |
ASTM A254 / A254M |
Copper-brazed double-wall steel tubing for brake, fuel, oil, heating, and cooling lines |
| EN / DIN |
DIN 74234 |
Hydraulic braking systems; brake pipes and flares |
| GOST |
GOST 11249-80 |
Double-layer brazed steel tubes for hydraulic pipelines including automobiles |
| JIS / JASO |
JASO M101:2022 / JIS G 3141 |
Automotive metal pipes for brake, fuel, and lubrication use; SPCC cold-reduced carbon steel sheet and strip |
| GB |
GB/T 34020.2-2017 / GB/T 699-2015 |
Double-wall copper-brazed steel tubes for automobile tubing systems; 10# as quality carbon steel substrate reference |
Application Fields
Automotive hydraulic braking systems
Used in hard brake lines between the master cylinder, ABS / ESC hydraulic unit, chassis routing sections, and wheel-end connections. ISO 4038 specifically addresses metallic brake pipes and fittings for hydraulic braking systems in road vehicles.
Automotive fuel and lubrication tubing
JASO M101 covers metal pipes for brake, fuel, and lubrication purposes, so the same Bundy tube platform can also serve selected automotive fluid-transfer circuits beyond braking.
General automotive and refrigeration line assemblies
ASTM A254 and SAE J527 both place this tubing family in automotive and similar line-service environments, including brake, fuel, oil, heating, and cooling circuits.
Aftermarket service and replacement kits
Suitable for repair, maintenance, restoration, and fleet-service use where stable bending and flare repeatability are critical for installation quality. This application is a practical extension of the brake-pipe forming requirements described in the relevant automotive tube standards.
Q: Are you trading company or manufacturer ?
A: manufacturer,also can do trading.
Q: How long is your delivery time?
A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,
it is according to quantity.
Q: Do you provide samples? is it free or extra ?
A: Yes, we could offer the sample for free charge but need pay the cost of freight.
Q: What is your terms of payment ?
A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.
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