1/4 in. x 1/4 in. (9/16-18) Brass Dual Master Cylinder Adapter
1/4 in. x 1/4 in. (9/16-18) Brass Dual Master Cylinder Adapter
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The 1/4 in. x 1/4 in. (9/16-18) Brass Dual Master Cylinder Adapter is a brass inverted flare adapter that transitions between inverted flare tube and NPT or other threaded port. Inverted flare fittings use a 37° internal cone seat (SAE J512) — the opposite geometry from the 45° external seat of SAE refrigeration flare fittings. The two standards are not interchangeable; mixing them results in an incomplete seal that will leak under pressure. Always verify flare angle before ordering.
Technical Specifications
| Specification | Value |
|---|---|
| Material | Brass |
| Flare Standard | SAE J512 / ISO 8434-1 (37° inverted flare) |
| Shape | See product title |
| Application | Automotive brake lines, fuel lines, hydraulic systems |
| Critical Note | NOT interchangeable with SAE 45° flare fittings |
Key Features
- 37° inverted (internal) flare seat — SAE J512 standard for automotive brake and fuel systems
- Metal-to-metal seat — no sealant required; the double-flared tube seals directly on the cone
- Vibration-resistant — the inverted flare is the DOT-approved standard for brake line connections
- NOT compatible with SAE 45° flare fittings — different cone angle will not seal
- Requires a double-flare tool to prepare tubing ends correctly
Common Applications
Automotive brake line connections (required by code), fuel system tubing, transmission cooler lines, power steering hydraulic lines, heavy equipment hydraulic brake circuits, and any high-vibration fluid circuit specified to the SAE J512 inverted flare standard.
Technical Resources
- SAE 45° vs. Inverted Flare — Identification Guide — Read before ordering
- Brass Fitting Types and Sizes Guide
Cross-References
This part is an equivalent for industry part numbers 08664-0409, 08683, 7908, 90171. Searching one of those? This is your match.