Description
OEX ACX0034 Single Firewall & Bulkhead Stud - Black
Route negative and earth cables cleanly and safely through firewalls and bulkheads with the OEX ACX0034 Single Firewall Bulkhead Stud, featuring two 3/8-16 thread brass stud terminals, 250A continuous rating, 48V DC maximum operating voltage, impact-resistant plastic insulator and mounting bush, glass-filled nylon base, stainless nuts, 10mm brass bolts, a compact 15.9mm length, and a 32mm diameter mounting hole for clean, professional negative cable pass-through in automotive, marine, 4WD, caravan, RV, and commercial vehicle electrical installations.
Product Overview
The OEX ACX0034 is the black-coded negative/earth variant of the OEX single firewall bulkhead stud range, providing a clean, insulated, and rated cable pass-through point for routing high-current negative or earth cables through metal firewalls, bulkheads, chassis rails, battery enclosure walls, and custom electrical panels. Paired with the ACX0035, the ACX0034 forms a complete colour-coded positive and negative bulkhead stud pair, allowing both the main positive and negative cables to pass cleanly through the same panel at properly rated, insulated, and identified connection points. This dual bulkhead stud approach is the professional solution for engine bay to cabin battery cable routing, battery box to accessory panel wiring, marine compartment bulkhead penetrations, and any custom build where both positive and negative cables need to cross a metal barrier cleanly without bare cable contact with the surrounding metalwork. The impact-resistant plastic insulator and mounting bush provide full electrical isolation between the stud and the surrounding metalwork, while the glass-filled nylon base delivers superior strength and heat resistance over standard nylon for reliable long-term performance in demanding installation environments. The dual 3/8-16 thread brass stud terminals allow cables to be terminated securely on both sides of the panel, with stainless steel nuts and 10mm brass bolts providing corrosion-resistant clamping that withstands automotive vibration and thermal cycling. Rated to 250A continuous and 48V DC maximum, the ACX0034 handles the demands of high-current 12V and 24V electrical systems. The compact 15.9mm body length suits standard automotive panel thicknesses, and the 32mm mounting hole suits standard hole saw sizes for straightforward installation. ISO 9001-certified manufacturing and in-house testing at OEX's Brisbane facility ensures consistent quality and long-term reliability.
Features & Benefits
Clean Insulated Negative Cable Pass-Through for Firewalls and Bulkheads: Provides a fully insulated, panel-mounted terminal point for routing high-current negative and earth cables through metal firewalls and bulkheads, eliminating the risk of cable chafing, insulation damage, and short circuits at metal panel penetration points in professional electrical builds.
Impact-Resistant Plastic Insulator and Mounting Bush: The impact-resistant plastic insulator and mounting bush provide full electrical isolation between the stud terminals and the surrounding metalwork, ensuring no continuity between the negative stud and the vehicle chassis or panel regardless of installation location or vibration.
Glass-Filled Nylon Base for Superior Strength and Heat Resistance: Glass-filled nylon construction provides significantly greater rigidity, impact resistance, and thermal stability compared to standard nylon, resisting deformation and cracking under sustained load and elevated temperatures in engine bays, battery compartments, and industrial equipment enclosures.
250A Continuous / 48V DC Rating: Rated to 250A continuous and 48V DC maximum, the ACX0034 handles the high current demands of large inverter earth cables, amplifier main earth runs, dual battery negative cables, and commercial vehicle auxiliary earth circuits in both 12V and 24V electrical systems.
2 x 3/8-16 Thread Brass Stud Terminals: Dual 3/8-16 thread brass stud terminals on both sides of the panel allow earth cables to be terminated cleanly on both the engine bay side and the cabin side, creating a secure, rated connection point that passes negative current through the panel without bare cable penetration.
Stainless Nuts and 10mm Brass Bolts for Reliable Connections: Stainless steel nuts combined with 10mm brass bolts provide corrosion-resistant, vibration-resistant clamping at both connection points, maintaining reliable electrical contact under thermal cycling and mechanical vibration common in automotive and marine installations.
Black Colour for Negative/Earth Identification: The black colour coding provides instant identification as a negative or earth terminal, reducing polarity errors in installations where both positive and negative bulkhead studs are mounted side by side on the same panel.
32mm Diameter Mounting Hole for Standard Tooling: The 32mm mounting hole suits standard hole saw sizes readily available at hardware stores, making installation straightforward without specialist tooling and ensuring a clean, professional finish on the panel surface.
ISO 9001 Certified Manufacturing: Produced under ISO 9001 quality management certification with in-house product testing at OEX's Brisbane facility, ensuring consistent quality and long-term reliability across automotive, marine, RV, mining, and commercial vehicle applications.
Technical Specs
| Specification |
Details |
| Part Number |
ACX0034 |
| Brand |
OEX |
| Type |
Single Firewall Bulkhead Stud |
| Colour |
Black |
| Max Operating Voltage |
48V DC |
| Continuous Rating |
250A |
| Stud Terminals |
2 x 3/8-16 Thread Brass |
| Nuts |
Stainless Steel |
| Bolts |
10mm Brass |
| Insulator / Mounting Bush |
Impact-Resistant Plastic |
| Base Material |
Glass-Filled Nylon |
| Terminal Material |
Brass |
| Body Length |
15.9mm |
| Mounting Hole Diameter |
32mm |
| Pack Quantity |
1 |
| Weight |
0.107kg |
| Warranty |
1 Year |
| Quality Certification |
ISO 9001 |
Compatible With / Goes Well With
The OEX ACX0034 suits 12V and 24V automotive, marine, caravan, RV, 4WD, commercial vehicle, and mining support vehicle applications requiring a clean, insulated, 250A-rated negative cable pass-through point through metal firewalls, bulkheads, chassis rails, battery box walls, and custom electrical panels. Ideal for engine bay to cabin negative cable routing, battery box to accessory panel earth wiring, marine bulkhead negative cable pass-through, and any installation where a high-current earth cable needs to cross a metal barrier safely. Pairs directly with the OEX ACX0035 red positive bulkhead stud for a complete colour-coded positive and negative bulkhead stud pair. Compatible with standard cable lugs for 3/8-16 thread studs across a range of heavy gauge wire sizes.
Frequently Asked Questions
What is the difference between the ACX0034 and the ACX0035?
The ACX0034 is the black-coded negative/earth variant and the ACX0035 is the red-coded positive variant. Both share identical specifications including 250A continuous rating, 48V DC maximum, dual 3/8-16 brass stud terminals, 15.9mm body length, and 32mm mounting hole. The ACX0034 additionally features a glass-filled nylon base. Use the ACX0035 for the positive cable pass-through and the ACX0034 for the negative/earth cable pass-through to form a complete, colour-coded bulkhead stud pair.
How far apart should the ACX0034 and ACX0035 be mounted when installed as a pair?
When installing both positive and negative bulkhead studs side by side, maintain sufficient separation to prevent accidental contact between the exposed stud terminals on either side of the panel. A minimum of 40 to 50mm centre-to-centre spacing is recommended as good practice, though the exact spacing depends on the cable lug sizes used and whether protective covers are fitted to the studs.
What size hole saw is needed to install the ACX0034?
The ACX0034 requires a 32mm diameter mounting hole, which suits a standard 32mm hole saw available at most hardware stores. Drill the hole in the intended mounting location, deburr the edges thoroughly, and test-fit the mounting bush before final installation to ensure a clean, tight fit.
What cable lugs are compatible with the 3/8-16 thread studs?
The 3/8-16 thread brass studs accept standard cable lugs with a 3/8" hole, available across a range of wire gauge sizes from light accessory wire through to heavy gauge cables used in 250A-rated automotive and marine applications. Always use correctly sized, properly crimped compression lugs matched to the wire gauge of each circuit.
Is the ACX0034 suitable for marine bulkhead installations?
The brass stud construction, impact-resistant plastic insulator, and glass-filled nylon base provide good corrosion resistance and electrical isolation suitable for marine bulkhead applications. For best long-term performance in marine environments, apply marine-grade sealant around the mounting bush perimeter during installation to prevent water ingress through the panel hole, and use tinned copper cable lugs with dielectric grease on all contact surfaces.
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