1" G Thread (BSPP) Female to 3/4" NPT Male Adapter with Washer — Lead-Free Brass

This adapter connects a 1" G (BSPP) female thread to a 3/4" NPT male thread, so you can join two different plumbing standards without replacing existing pipework. It's made from lead-free brass and ships with a washer, since G (BSPP) threads are parallel and seal with a washer rather than tape or sealant.

What It Connects

• Female side: 1" G (BSPP) — parallel thread
• Male side: 3/4" NPT — tapered thread

Key Features

• Lead-free brass construction, safe for potable water
• Washer included for a proper seal on the G thread side
• Simple screw-in installation, no special tools required

Common Uses

• Shower systems and shower arm connections
• Hose-to-fixture adapters
• Fixture retrofits where thread types don't match

Specifications

Package Includes

• 1 x Adapter, 1" G Female to 3/4" NPT Male
• 1 x Washer

Installation Notes

1. Confirm your existing fittings match: 1" G female on one side, 3/4" NPT male on the other.
2. Seat the included washer on the G thread side before threading — this is what creates the seal.
3. Hand-tighten first, then snug with a 1 3/8" wrench. Don't overtighten.
4. Plumber's tape can be used on the NPT male side if needed.
5. Run water briefly and check the joint before finishing the install.

FAQ

What's the difference between G thread and NPT thread?
G thread (BSPP) is parallel and seals with a washer. NPT is tapered and seals by compression. This adapter connects the two.

Do I need plumber's tape?
The G thread side seals with the included washer. Tape is optional on the NPT male side.

Is this safe for drinking water?
Yes, it's lead-free brass, rated for potable water use.

What size wrench do I need?
The hex measures 1 3/8" (38mm) across the flats.

Will this fit my shower system?
If your shower system uses a 1" G female connection and you need to connect to 3/4" NPT, yes.