NG1 Fractional Masthead Assembly


NG1 Fractional Masthead Parts

NG1 Fractional Masthead Assembly - Complete: NG1-1FAC: The NG1 Fractional Rig Masthead Assembly is a single casting, NG1-1FB, welded to the Mast Section which allows for 2 Main halyards (or 1 Halyard and a topping lift) using a single 'Drop-in' Sheave Axle, NG1-6, and (2) 60mm Sheaves, NG1-4. Different (depending on Mast Section) Masthead Cover Plates, below, keep Sheaves and Axle in place, while providing level surface for mounting Anchor light or instrumentation. Masthead includes provisions for attachment of a Backstay, and (2) Upper shrouds (rarely used) using Stemball rigging fittings. Commonly used on NG-28 through NG-51 and similar Mast Sections.
	NG1 Fractional Masthead Body: NG1-1FB: The NG1-1FB Fractional Masthead Body is a single casting welded into the Mast Section. The main frame for the *NG1-1FAC* Fractional Masthead Assembly, the NG1 Fractional Masthead Body is (maximum) 5 1/16" (130mm) wide x 10" (255mm) long (on top).
NG1 Masthead Sheave, 60mm: NG1-4: Factory standard Acetyl Sheave is 60mm (2 5/16") OD x 14mm (9/16") wide x 10mm (3/8") ID.
	NG1 Masthead Sheave, 60mm Aluminum: NG1-4A: Anodized Aluminum Sheave is 60mm (2 5/16") OD x 14mm (9/16") wide x 10mm (3/8") ID, and is much sturdier than the plastic version.
NG1 Masthead Sheave Axle: NG1-6: SS 'Drop-in' Sheave Axle pin is 10mm (3/8") diameter x 40.8mm (<1 5/8") long. Used for all Sheaves in all NG1 Mastheads.

NG1 Fractional Masthead Cover Plate - Standard: NG1-1F:

Cast aluminum Masthead Cover Plate for NG1 Fractional Rig Masthead commonly used on NG28, NG31, NG37 Masts and others where the front of the Mast Section is 10 1/4" (260mm) from the back of the Masthead. Masthead Cover Plate also serves as Sheave separator, provides level surface for mounting Anchor light, and has slots for exiting other electrical wires. Standard Cover Plate is 2 11/16" (maximum) wide x 6 1/4" long (on top) and is fastened through the front of the mast with one (1) 5mm screw: NG1-1SF:

NG1 Fractional Masthead Cover Plate - Wide: NG1-1FX:

Wide Masthead Cover Plate for NG1 Fractional Rig Masthead is commonly used on NG28, NG31, NG37 Masts and others where the front of the Mast Section is 10 1/4" (260mm) from the back of the Masthead. interchangeable with NG1-1F, above, extra width and single hole for electrical wires minimizes water entrance. Cast aluminum Cover Plate also serves as Sheave separator, while providing level surface for mounting Anchor light or instrumentation. Wide Cover Plate is 2 7/8" (maximum) wide x 6 1/4" long (on top) and is fastened through the front of the mast with one (1) 5mm screw: NG1-1SF:

NG1 Fractional Masthead Cover Plate - Long: NG1-1FXL:

Long Masthead Cover Plate for NG1 Fractional Rig Masthead is commonly used on NG46 and NG51 Masts and others where the front of the Mast Section is 11 1/4" (285mm) from the back of the Masthead. Cast aluminum Cover Plate also serves as Sheave separator, provides level surface for mounting Anchor light, and has a hole for exiting electrical wires. Long Cover Plate is 2 7/8" (maximum) wide x 7 1/4" long (on top) and is fastened through the front of the mast with one (1) 6mm screw: NG2-1S:


NG1 Stemball Cup Washer - 26x11: NG1-CW11: Standard NG1 Stemball Cup Washer is used with swage and mechanical Stemballs in NG1 Mastheads, Spreader Bases, some Stemball Backing Shells, and in other applications. Type 316 SS Cup Washer is 26mm (>1") OD x 11mm (7/16") ID x 11.5mm (7/16") high. For use with 5/32", 3/16", 7/32", 4mm, and 5mm Standard Swage Stemballs, and 5/16", 3/8", and 7/16" threaded Stemballs.
NG1 Stemball Cup Washer - 26x13: NG1-CW13: Standard NG1 Stemball Cup Washer is used with swage and mechanical Stemballs in NG1 Mastheads, Spreader Bases, some Stemball Backing Shells, and in other applications. Type 316 SS Cup Washer is 26mm (>1") OD x 13mm (>1/2") ID x 11.5mm (7/16") high. For use with 7/32", and 5mm Standard Swage Stemballs, and 7/16" threaded Stemballs.
NG1 Stemball Cup Washer - 26x16: NG1-CW16: Standard NG1 Stemball Cup Washer is used with swage and mechanical Stemballs in NG1 Mastheads, Spreader Bases, some Stemball Backing Shells, and in other applications. Type 316 SS Cup Washer is 26mm (>1") OD x 16mm (5/8") ID x 11.5mm (7/16") high. For use with 1/4", 9/32", 6mm, and 7mm Standard Swage Stemballs, and 1/2", threaded Stemballs.

NG1 Stemball / Eye Adapters
*NG1 Stemball / Eye Adapter for 3/8" (10mm) Pin: NG1-SBE-6:* *NG1 Stemball / Eye Adapter for 7/16" (11mm) Pin: NG1-SBE-7:* *NG1 Stemball / Eye Adapter for 1/2" (12mm) Pin: NG1-SBE-8:* SS NG1 Stemball / Eye Adapters have a 26mm (>1") head diameter. Length from base of Stemball to Pin center is 4" (100mm), or 4 1/4" (108mm) on 1/2" size. A variety of other NG1 Stemball / Eye Adapters are available with or without a Toggle, See: NG1 Stemball / Eye Adapters.
Swage Stemballs for Imperial Wire
Swage Stemball for 5/32" Wire: RS-SB-M4: Swage Stemball for 3/16" Wire: RS-SB-3/16: Swage Stemball for 7/32" Wire: RS-SB-7/32: Swage Stemball for 1/4" Wire: RS-SB-1/4: Swage Stemball for 9/32" Wire: RS-SB-M7: Standard NG1 Stemball Swage is used with Imperial (US Standard) 1x19 wire and appropriate Stemball Cups in NG1 Mastheads, Spreader Bases, some Stemball Backing Shells, and in other applications.
Swage Stemballs for Metric Wire
Swage Stemball for 4mm Wire: RS-SB-M4: Swage Stemball for 5mm Wire: RS-SB-M5: Swage Stemball for 6mm Wire: RS-SB-M6: Swage Stemball for 7mm Wire: RS-SB-M7: Standard NG1 Stemball Swage is used with Metric 1x19 wire and appropriate Stemball Cups in NG1 Mastheads, Spreader Bases, some Stemball Backing Shells, and in other applications.

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Spars, Rigging, and Hardware for Sailboats

	Spars, Rigging, and Hardware for Sailboats Rig-Rite, Inc. Phone: (001) 401-739-1140 -- FAX: (001) 401-739-1149 www.RigRite.com Ordering/Questions
Isomat NG1 Fractional Masthead

The NG1 Fractional Rig Masthead is commonly used on Isomat Fractional Masts using the NG-28 through NG-51 (tapered and untapered) Mast Sections, See: NG Mast Sections. Larger NG Mast Sections use a welded semi-custom Fractional Masthead. For NG1 Masthead Rig Mastheads, See: NG1 Masthead.