The best 5/8-inch brass cap depends on the fitting style: choose a flare cap for an SAE 45-degree flare connection or a compression cap for a compatible compression fitting. Hooshing and Uenede offer flare caps, while PATIKIL and LTWFITTING offer compression caps. The options below include different pack sizes, so you can compare connection type and quantity before buying.
| Product | Fitting type | Best for |
|---|---|---|
| Hooshing 2PCS Brass Flare Cap | SAE 45-degree flare | A small two-cap supply |
| PATIKIL 30-Piece Compression Cap | Compression | Bulk quantity |
| Uenede 4-Piece Flare Female Cap | SAE 45-degree flare | A four-cap flare set |
| PATIKIL 10-Piece Compression Cap | Compression | A smaller compression pack |
| LTWFITTING Compression Cap | Compression | A straightforward 10-piece set |
Hooshing 2-Piece Brass Flare Cap
Best for buyers who need a small quantity of caps for 5/8-inch tube OD SAE 45-degree flare fittings. This two-piece set is designed to terminate a flared tube connection, making it a relevant choice when the fitting itself is a flare connection rather than a compression or pipe-thread connection.
The listed applications include fuel, oil, air, propane, LP and natural gas lines, refrigeration, and hydraulic uses. The product information also describes use with flared copper, brass, aluminum, and steel tubing. Match the fitting style and application requirements before installation.
- Choose this if: You need two female flare caps for compatible tubing.
- Limitation: This is a flare cap, so it is not a substitute for a compression cap or NPT pipe cap.
PATIKIL 30-Piece Compression Cap
Best for buyers who need a larger stock of brass compression caps. The product is specified for 5/8-inch outside-diameter tubing and lists a 13/16-18UNS thread size. PATIKIL describes these caps as suitable for sealing tubing and joints in fuel, water, air, oil, or gas lines.
The listing identifies brass construction and describes corrosion resistance, high-temperature ductility, and precise threads. The 30-piece package may suit maintenance work or situations where multiple caps are needed, rather than a single repair.
- Choose this if: You want a bulk pack and have confirmed the 5/8-inch tube OD and thread specification match your fitting.
- Limitation: Its compression-cap design and stated thread size must match the existing connection; 5/8 inch alone does not identify a fitting type.
Uenede 4-Piece Brass Flare Cap
Best for buyers seeking a four-cap supply for 5/8-inch tube OD SAE 45-degree flare connections. Uenede describes these as female flare caps for terminating or closing a pipe end. The product listing calls out solid brass construction, deep and accurate threads, and corrosion resistance.
This set is a better fit for flare connections than for compression joints. Its stated size and 45-degree flare design are the key details to verify against the fitting being capped.
- Choose this if: Your connection is a compatible SAE 45-degree flare and four caps meet your needs.
- Limitation: The listing does not describe these as compression caps, so avoid choosing them based only on a 5/8-inch measurement.
PATIKIL 10-Piece Compression Cap
Best for buyers who want PATIKIL’s specified compression-cap style in a smaller pack than its 30-piece option. The listing gives a 5/8-inch tube OD, 13/16-18UNS thread size, and brass construction. Listed uses include sealing connections for water, air, fuel, oil, or gas.
Its listed dimensions are 15.5 by 24 mm. The product details describe precise threading and brass properties intended for durable use. Compare the thread size with the existing fitting before ordering, especially if the connection is described only as “5/8 inch.”
- Choose this if: You need a modest quantity and the connection matches the listed compression-cap specifications.
- Limitation: It is not the bulk option; the 30-piece version may be more appropriate when higher quantity is the priority.
LTWFITTING 10-Piece Compression Cap
Best for buyers looking for a basic 10-pack of 5/8-inch brass compression caps. The supplied product details identify the fitting type as a compression cap, the tube size as 5/8-inch OD, and the material as brass. These core specifications make it easy to compare with other compression options in this list.
Compared with the PATIKIL packs, this listing provides fewer detailed thread and application specifications. Check the exact fitting and thread requirements before purchase rather than assuming that every 5/8-inch cap uses the same connection.
- Choose this if: You need ten brass compression caps and the 5/8-inch OD specification matches your tubing.
- Limitation: The supplied feature information does not state a thread size or list specific service applications.
Buying Guide: How to Choose a 5/8-Inch Brass Cap
Is your fitting flare, compression, or pipe thread?
Identify the connection type before selecting a cap. A flare cap seals a compatible flared fitting, while a compression cap is intended for a compression connection. A threaded pipe cap, such as an NPT cap, uses a different thread system. These styles are not interchangeable simply because a listing mentions 5/8 inch.
What does 5/8 inch refer to?
For the compression products above, 5/8 inch is listed as the tube outside diameter. The PATIKIL listings also specify a 13/16-18UNS thread. The flare products specify 5/8-inch tube OD with an SAE 45-degree flare. Check the fitting’s measurements and connection description instead of relying on nominal size alone.
How many caps should you buy?
Choose pack size based on the number of connections you need to close and whether you want spares. The listed options include two- and four-piece flare sets, 10-piece compression packs, and a 30-piece compression pack. A larger pack does not help if its fitting style or thread does not match your application.
What should you verify before installation?
- Confirm the fitting type, tube outside diameter, and thread specification.
- Check that the cap is intended for the material and service involved.
- Follow applicable equipment instructions and requirements for gas, fuel, refrigeration, or hydraulic systems.
- Do not force a cap onto a connection that does not thread or seat correctly.
Frequently Asked Questions
Are all 5/8-inch brass caps interchangeable?
No. A 5/8-inch measurement can refer to tube outside diameter, while flare, compression, and pipe-thread caps have different connection designs. Match the cap to the fitting type and thread.
What is the difference between a flare cap and a compression cap?
A flare cap is designed for a compatible flared connection, such as the SAE 45-degree style listed for the Hooshing and Uenede products. A compression cap is designed for a compatible compression fitting.
Which listed caps are intended for 5/8-inch tube OD?
All five products are listed for 5/8-inch tubing or 5/8-inch tube OD. The flare options specify SAE 45-degree flare connections; the compression options specify compression fittings.
Should I choose a 10-piece or 30-piece pack?
Choose a 10-piece pack when you need a smaller quantity. Choose the PATIKIL 30-piece option when you need more caps, after confirming its compression design and 13/16-18UNS thread match your fitting.