How do D.O.T transmission fittings differ from regular fittings used in other applications?

D.O.T transmission fittings, also known as Department of Transportation fittings, are specifically designed and manufactured for use in automotive brake systems. They have several key differences compared to regular fittings used in other applications:

1. Material: D.O.T transmission fittings are typically made from brass or steel materials with high corrosion resistance and durability. This is important for ensuring the fittings can withstand the pressures and harsh conditions of automotive brake systems.

2. Size and Shape: D.O.T transmission fittings come in standard sizes that are designed to match the specifications of brake lines, typically 1/4", 3/8", or 1/2". The fittings have specific shapes and thread patterns to ensure proper connection to brake lines and components.

3. Double Compression Sleeve: D.O.T transmission fittings have a unique double compression sleeve design. This design provides a secure and leak-free connection by compressing the brake line against both the fitting body and the twice-flared end of the brake line.

4. Tapered Thread: D.O.T transmission fittings use tapered threads, such as 45 degrees inverted flare or 60 degrees double flare, to create a tight and reliable connection. These tapered threads help prevent leaks and ensure the fittings can handle the high pressures involved in brake systems.

5. Compliance: D.O.T transmission fittings are required to meet specific safety standards and regulations set by the Department of Transportation. These standards ensure that the fittings are safe, reliable, and compatible with other brake system components.

It's important to note that D.O.T transmission fittings should only be used in automotive brake systems and not substituted for regular fittings in other applications, as they may not have the necessary characteristics for proper functioning and safety.