UISB

Menu
Menu

Fuel Filler

Neck

Precision-formed STKM 11A steel assemblies — bent, brazed, dual leak-tested and surface-treated for demanding automotive OEM programs.

Explore Specifications View Process
Product Overview

Engineered for Demanding Environments

Our fuel filler neck is made from STKM 11A, a low-carbon steel tube known for its strength, durability, and manufacturability. It offers reliable mechanical performance while remaining ductile enough for bending and forming into complex shapes, and its low carbon content makes it easy to weld and machine, supporting precise manufacturing.

"STKM 11A's tensile strength of 290–390 MPa ensures dependable performance, structural integrity, and long service life under normal operating conditions, making it well-suited for fuel filler neck applications."

Dual Leak Testing

Tested before and after coating — zero-pinhole integrity at every stage.

CNC Precision Bending

Complex geometries formed to exact angles and radii with verified tolerances.

Automotive OEM Compliance

Manufacturing processes aligned to automotive industry quality standards.

Technical Specifications

Engineering Grade Materials

Two pipe categories — each with distinct dimensional ranges and material variants, engineered for their specific role in the assembly.

Primary Component
Main Filler Neck Pipe
STKM 11A — JIS G3445 Low-Carbon Steel Tube
Tensile Range290–390 MPa
WeldabilitySuperior
DuctilityExcellent
Low Carbon <0.12% CNC Bending Ready Superior Weldability High Ductility Precision Formable
Secondary Component
Levelling Vent Pipe
Carbon Steel — Plain, Galvanized & Nickel-Coated
Length Coverage650–1,180 mm
Corrosion ProtectionHigh
Joint IntegrityBrazed Seal
Plain Carbon Steel Galvanized Nickel-Coated Brazed Joint Leak-Proof
Variants

Premium Surface Treatments

High-quality coating and plating processes delivering exceptional corrosion resistance, durability and an attractive finish — performed by certified partners to automotive standards.

Silver Finish
Bright silver plating delivering a premium metallic appearance with outstanding corrosion protection. Ideal for components requiring high reflectivity and a clean factory aesthetic throughout the product lifecycle.
Excellent corrosion resistance
Automotive OEM approved
Long-term surface durability
Metallic Grey
Sophisticated dark metallic grey coating offering a contemporary industrial aesthetic. Provides superior protection against moisture, rust and harsh chemical environments in underbody automotive applications.
Chemical & moisture resistant
Industrial grade durability
Uniform application quality
Black Painted
Premium matte-to-gloss black finish combining aesthetic refinement with superior environmental protection. Maximum UV resistance maintains consistent appearance under demanding automotive operating conditions.
UV & heat resistant
Rust & moisture protection
Premium appearance retention
Manufacturing Excellence

12-Stage Production Process

From raw steel tube to finished, tested and packaged component — every stage is monitored for dimensional accuracy, weld integrity and surface quality.

UIG
01
Forming Stage
Bending
Shaping the tube into a specific angle and radius using a CNC tube bending machine, with dimensions checked against design specifications.
UIG
02
Forming Stage
Expansion
Enlarging the tube's diameter at one end using a hydraulic tube expansion machine, so it fits the fuel cap housing or connecting hose. The expanded end is inspected for correct dimensions and a smooth surface finish.
UIG
03
Forming Stage
Cutting
Trimming the steel tube to the required length using a tube cutting machine, according to design specifications.
UIG
04
Forming Stage
Forming
Shaping both ends of the tube using a hydraulic end-forming machine, creating the required geometry for the fuel cap housing and hose connection.
UIG
05
Forming Stage
Piercing
Punching a hole in the steel tube using a piercing machine, according to design specifications for the vent tube connection. The hole is then inspected and deburred before moving to the next process.
UIG
06
Joining Stage
Brazing
Joining the levelling vent pipe to the main filler neck with a brazed seal, producing a permanent, leak-proof connection between the two components.
UIG
07
Quality Stage
First Leak Test
Verifying braze and tube integrity before surface treatment — the component is checked for leakage and surface pinholes so defects are caught before coating cost is added.
UIG
08
Finishing Stage
Coating
Applying a protective layer to the fuel filler neck to improve corrosion resistance and surface durability. After curing, the finished surface is inspected for quality and uniformity.
Scroll to Top