Stainless Steel 56 mm Radiator Filler Neck & 15 lb Pressure Cap (304 Grade)

Heavy-duty 304 stainless filler neck with matching short-reach pressure cap—ideal for custom radiator/header tank builds and repairs.

Item Description

This stainless steel radiator filler neck and cap set is designed for secure, reliable sealing on pressurised cooling systems. The neck is manufactured from 304 stainless steel for corrosion resistance and long service life, and is suitable for welding to a radiator or header tank.

Neck Sizes

Top Diameter (cap twist-on) 56 mm
Inner Depth 20 mm
Collar 42.5 mm
Bottom Hole (seats into tank) 29.5 mm
Wall Thickness 0.9 mm

Please note: The 8 mm overflow is loose in the neck and will require welding in position prior to welding the neck to the radiator or header tank.

Pressure Cap

  • Pressure Rating: 15 lb
  • Stamping: Cap is stamped “15 Bar”
  • Outside Diameter: 60 mm
  • Reach: Short reach

Tip: Please ensure you are matching the cap reach/style to your application before purchase.

Material

  • Neck: 304 Stainless Steel
  • Cap Case: 304 Stainless Steel
  • Stock items: Dispatched in 1–2 working days.
  • Made-to-order / custom items: Dispatched in 2–4 working days.
Smooth Checkout

Enjoy a smooth checkout process. If you have any questions about sizing or fitment, message us via eBay before ordering.

Customer Support

We are at your side both before and after the purchase with words and deeds. Contact us if you have any questions using the eBay contact form and we will get back to you as soon as possible.

Returns

30 Day Returns. Please return items in unused condition and in original packaging where possible.

Thank you for your business.


Heavy-duty 304 stainless filler neck with matching short-reach pressure cap—ideal for custom radiator/header tank builds and repairs. This stainless steel radiator filler neck and cap set is designed for secure, reliable sealing on pressurised cooling systems. The neck is manufactured from 304 stainless steel for corrosion resistance and long service life, and is suitable for welding to a radiator or header tank. Please note: The 8 mm overflow is loose in the neck and will require welding in position prior to welding the neck to the radiator or header tank. We are at your side both before and after the purchase with words and deeds. Contact us if you have any questions using the eBay contact form and we will get back to you as soon as possib