Adapter screw connection 5/8 "to 3/4"

SKU: R102
GTIN: 4251943209005
Category: Screw connections

Transition fitting 5/8" female thread to 3/4" male thread, e.g. for old kegs

3,03 €

incl. 19% VAT , plus

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Delivery time: 2 - 3 Workdays (DE - int. shipments may differ)

A 5/8" female thread to 3/4" male thread transition fitting is an adapter that reliably connects two components with different thread sizes. In the case described, it is used to connect Convert old keg closures with a 5/8" female thread (UNF thread on the CO₂ side) to a more modern or more common 3/4" male thread – for example, to be able to install new regulators or connections.

Technical description:

Material: Usually made of nickel-plated brass, stainless steel, or anodized aluminum for pressure resistance and corrosion protection.
Thread side 1 (internal):
- 5/8" UNF female thread, suitable for old CO₂ keg connections or fittings that still use this standard.
- UNF stands for "Unified National Fine," which is an American fine thread.
Thread side 2 (outside):
- 3/4" external thread, often designed as BSP (British Standard Pipe) or NPT (National Pipe Thread) – depending on the country of use and standard.
- Enables connection to modern regulators, pipes, or gas distributors.

Application example:

You want to use an old KEG barrel with a keg closure whose CO₂ side still has a 5/8" thread. However, modern CO₂ regulators or gas lines use 3/4" connections. This transition fitting allows you to connect both parts securely without completely replacing the old part.

Installation instructions:

Cleaning: Thoroughly clean the threads on both sides (free of grease and dust).
Seal:
- We recommend sealing tape (Teflon tape) to seal the threaded connection.
- Alternatively, metal adhesive (e.g., high-pressure thread sealant such as Loctite 577) can be used – this provides a permanent, vibration-proof seal.
Assembly:
- Screw in the thread by hand, then tighten with a suitable open-end or box-end wrench.
- Do not overtighten – excessive tightening can damage the thread when metal is in contact with metal.
Leak test: After assembly, pressurize the system and check for leaks using leak detection spray or soapy water.