Lycoming Straight Hose Nipple – 3/8" I.D. Oil Drain Tube Fitting

The STD-684 Straight Hose Nipple is a precision-machined fitting designed for use in Lycoming engine oil drain tube assemblies. This fitting provides a secure connection between the cylinder oil drain tube and the flexible oil drain hose, helping ensure proper oil return and leak-free operation.

Manufactured from durable, corrosion-resistant material, the STD-684 is built to withstand the high temperatures and harsh operating conditions commonly found in aircraft engines. It is an ideal replacement for worn, damaged, or corroded fittings during engine maintenance or overhaul.

Features

• Precision-machined straight hose nipple
• Fits 3/8" I.D. oil drain hose
• Provides a secure, leak-resistant hose connection
• Corrosion-resistant construction for long service life
• Ideal for maintenance, repair, or overhaul of Lycoming oil drain tube assemblies

Drawing #5

Specifications

• Part Number: STD-684
• Type: Straight Hose Nipple
• Hose Size: 3/8" I.D.
• Material: Corrosion-resistant metal
• Condition: New

Common Applications

Used in oil drain tube assemblies on many Lycoming 4-cylinder and 6-cylinder engines, including selected models in the:

• O-320
• IO-320
• O-360
• IO-360
• O-540
• IO-540
• AEIO-540
• TIO-540
• HIO-540

Note: Always verify compatibility with your engine's configurations may vary by engine model and serial number.