SPEEDAIRE
SPEEDAIRE 30E667 Coupler Plug, 3/8 in Female NPT, Steel
Steel coupler plug with 3/8 in female NPT threads, rated to 300 psi and -40°F to 150°F, meets ISO 6150 and MIL-C-4109F standards
- Industrial-standard interchange fits existing 1/4 in couplers
- 300 psi rating handles high-demand air tools
- Steel body with zinc plating resists corrosion
- Buna-N seals perform from -40°F to 150°F
- Female 3/8 in NPT threads connect directly to hose
Coupler plug for industrial air lines
The SPEEDAIRE 30E667 coupler plug is the male half of an industrial interchange connection. It threads onto a 3/8 in female NPT hose or tool inlet with a 1/4 in body size. The steel body has a zinc-plated finish and uses Buna-N seals rated from -40°F to 150°F. It suits workshops that need quick, tool-less coupling changes.
Pressure and thread limits
Maximum working pressure is 300 psi at 70°F. The NPT thread form seals by taper engagement, so correct thread tape or compound is required to prevent leaks. The plug meets ISO 6150 and MIL-C-4109F for dimensional interchange, but it has no internal valve. It is not for buyers who need a shut-off function when disconnected.
Simple install with common pitfalls
Installation is hand-tight plus one to two turns with a wrench on the hex flats. Over-tightening cracks the port or distorts the threads. The most common issue is mismatching the 1/4 in body size with a 3/8 in body coupler, which prevents locking. Verify the interchange standard before use.
Highlights
- Industrial-standard interchange fits existing 1/4 in couplers
- 300 psi rating handles high-demand air tools
- Steel body with zinc plating resists corrosion
- Buna-N seals perform from -40°F to 150°F
- Female 3/8 in NPT threads connect directly to hose
Specifications
| Brand | SPEEDAIRE |
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Questions about this item
Should I pick the 3/8 in female NPT plug or another size?
This plug has a 3/8 in female NPT hose fitting and a 1/4 in body size. Choose it when your hose or tool inlet matches those exact dimensions.
What does the 300 psi rating mean once the plug is installed?
The 300 psi maximum working pressure at 70°F is the highest air pressure the sealed connection can safely handle in service.
How does the industrial interchange standard limit what couplers I can use?
It mates only with industrial-standard couplers of the same 1/4 in body size; other interchange types will not seal.
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