Stainless Steel Straight Thru-Hulls,Threaded

Each Thru-Hull and Scupper Valve is available with a new silicone gasket and are backed by Attwood's trusted Lifetime Warranty! Why specify plastic parts when these fittings will last the life of the boat. They offer unique multi-thread design with NPSM and NPT threads with plenty of thread length that allows direct connection to seacocks or pipes.

Rugged Stainless Construction

Cast from certified enhanced #316 Stainless Steel allow for strength and lifetime corrosion-resistance
We polish all visible areas to a mirror finish, then each part through a passivation for additional protection
Thick steel sidewalls withstand continual stress and hose flexing

Solid Solicone Gasket

Gasket is dimensionally stable--will not deteriorate or shrink over time
Excellent resistance to UV & weather-aging
Watertight, fool-proof, one-piece seal
Eliminates the need to form and apply sealant or caulk

Caution: Thru-Hull connectors are designed for installation above the water line only.

Lifetime Warranty

A Flange Dia.	B Thread O.D.	C Total Length	Installation HoleSaw Size	Threads NPSM	Max Hull Thickness	Bulk Without Gasket	Bulk With Gasket	Aftermarket Packaging*
1-7/8" I.D.	2-1/8"	2-1/2"	1-1/8"	3/4"	1-5/8"	66559-1	66559G1	-
2-1/4" I.D.	2-1/4"	2-5/8"	1-3/8"	1"	1-3/4"	66561-1	66561G1	-
3" I.D.	2-3/8"	2-3/4"	2"	1-1/2"	1-7/8"	66563-1	66563G1	-

A Flange Dia.

B Thread O.D.

C Total Length

Installation HoleSaw Size

Threads NPSM

Max Hull Thickness

Bulk Without Gasket

Bulk With Gasket

Aftermarket Packaging*

1-7/8" I.D.

2-1/8"

2-1/2"

1-1/8"

3/4"

1-5/8"

66559-1

66559G1

2-1/4" I.D.

2-1/4"

2-5/8"

1-3/8"

1-3/4"

66561-1

66561G1

3" I.D.

2-3/8"

2-3/4"

1-1/2"

1-7/8"

66563-1

66563G1

warranty contact us terms of use copyright privacy policy

attwood | 1016 n. monroe st. | lowell, mi 49331 | 616.897.9241 | Web Development by Bevelwise