Isomat NB40 Boom

NG2 Gooseneck Bracket: NG2-11: Cast aluminum Gooseneck Mast Bracket for use with NB-32, NB-40, and NB-55 new-style Gooseneck Assemblies. Bracket for NG-51 through NG-86 Mast Sections is 4 3/4" (120mm) high x 3 1/2" (90mm) wide, and is fastened with eight (8) 1/4" (6mm) rivets. Bracket has 22mm (7/8") hole at top and 8mm (5/16") hole on bottom side, for use with any of the NB2-1 Vertical Gooseneck Toggle Pins. Though actually a Mast Component, this item is also listed here for your convenience.
NB-40 Gooseneck Assembly Complete: NB40-1AC: Cast aluminum Gooseneck Assembly incorporates provisions for internal outhaul and 3 internal reef lines. Internal lines run over delrin sheaves, and down past lever action cams. Cams can be removed to allow lines to go straight down to the deck. Includes Vertical Gooseneck Toggle Pin with reef hooks, and tack shackle. For use with Isomat Gooseneck Mast Bracket (NG2-11), which has 7/8" hole at top and 5/16" hole on bottom side. Parts for NB-40 Gooseneck Assembly.
NB-40 Gooseneck Ass'y: NB40-1A: As *NB40-1AC, above, but with sheaves, cams, and axles only. Does not* include Vertical Gooseneck Toggle Pin with reef hooks, and tack shackle. Parts for NB-40 Gooseneck Assembly.
	NB-40 Gooseneck Casting: NB40-1: Replacement Casting only, for any of the NB-40 Gooseneck Assemblies listed above.
	NB2 Boom Sheave: NB2-10: Acetyl Sheave is 60mm (2 5/16") OD x 14mm (9/16") wide x 10mm (3/8") ID, and fits in upper (aft) slot in Gooseneck Casting.
	NB2 Boom Sheave - Aluminum: NB2-10A: 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.

*Spar Cleat – 6 3/8": NGC-6:* Cast Aluminum Cleat is 160mm (6 3/8") long. Other Cleats have also been used on this boom section, and are listed separately. Other Isomat Cleats.
Exit Plate – Large Snap-in: NG2-7: Large Black plastic Snap-in Exit Plate eliminates line chafe, and accommodates a maximum of 5/8" line. Exit Plate measures 4 1/2" x 1 5/16" (115mm x 34mm), and installs in cut-out 1" x 4 1/4" (26mm x 112mm). Other Exit Plates have also been used on this boom section, and are listed separately. Other Isomat Exit Plates.
AutoReef Internal Shuttle Block: NB2-20: Cast aluminum Shuttle Block incorporates (2) 35mm (1 3/8") Delrin Roller sheaves, NB2-20R. Used with Isomat AutoReef (single line) Reefing System.

NB2 Boom Bail Ass'y: NB2-15A: SS Articulating Boom Bail fits in integral slot in underside of NB-32, NB-40, NB-55, and other boom sections with an underside boom bail slot that is 31mm wide x 4.5mm deep. Bail is made from 10mm rod. Formed plate is 3.2mm thick and measures 4 3/4" (120mm) long x 1 3/16" (30mm) wide. Fastens with (2) 1/4" (6mm) rivets.
	NB2 Boom Bail: NB2-15R: SS formed rod bail only, as used in NB2 Boom Bail Assembly NB2-15A, above. Bail is made from 10mm (3/8") rod, and is 2 3/4" (70mm) long x (maximum) 1 15/16" (50mm) high.
	NB2 Boom Bail Plate: NB2-15BP: SS formed plate only, as used in NB2 Boom Bail Assembly NB2-15A, above. Plate is 3.2mm thick and measures 4 3/4" (120mm) long x 1 3/16" (30mm) wide. Fastens with (2) 1/4" (6mm) rivets.
NB2 Boom Bail Ass'y - Heavy-duty: NB2-15AW: As NB2-15A (above), but Bail is reinforced with a welded crossbar. This heavy-duty option prevents the bail from compressing in extreme circumstances and is used primarily on larger boats.
	NB2 Heavy-duty Boom Bail: NB2-15RW: SS formed rod Bail only, reinforced with a welded crossbar, as used in NB2 Heavy-duty Boom Bail Assembly NB2-15AW, above. Bail is made from 10mm (3/8") rod, and is 2 3/4" (70mm) long x (maximum) 1 15/16" (50mm) high.

*NB2 Boom Vang Attachment Lug - 14mm (9/16"): NB2-16-14:* SS Boom Vang Attachment Lug fits in integral slot in underside of NB2 and FB2 Boom sections and has 14mm (9/16") hole for attachment of Sparcraft Pneuvang. Slide plate (3mm) is 6 1/2" long, and is welded to 5mm (3/16") thick Triangle. Unit slides into track and fastens with (4) 1/4" (6mm) rivets. Also used with NG1 Isovang. *
*NB2 Boom Vang Attachment Lug - 16mm (5/8"): NB2-16-16:* SS Boom Vang Attachment Lug fits in integral slot in underside of NB2 and FB2 Boom sections and has 16mm (5/8") hole for attachment of Vang. Slide plate (3mm) is 6 1/2" long, and is welded to 5mm (3/16") thick Triangle. Unit slides into track and fastens with (4) 1/4" (6mm) rivets.
*NB2 Boom Vang Attachment Lug - 22mm (7/8"): NB2-16-22:* SS Boom Vang Attachment Lug fits in integral slot in underside of NB2 and FB2 Boom sections and has 22mm (7/8") hole for attachment of NG2 Isovang. Slide plate (3.2mm) is 8" long, and is welded to 6mm (1/4") thick Triangle. Unit slides into track and fastens with (4) 1/4" (6mm) rivets.
*FB3 Boom Vang Attachment Lug - 22mm (7/8"): FB3-16C-22:* Heavy-duty Cast SS Boom Vang Attachment Lug fits in integral slot in underside of NB2 and FB2 Boom sections and has 22mm (7/8") hole for attachment of NG2 Isovang. Investment Cast SS Vang Attachment Lug is 255mm (10") long x 29mm (maximum) wide, hole center is 65mm (2 1/2") from Boom bottom. Unit slides into track and fastens with (6) 1/4" (6mm) rivets.

Isomat Isovang Isomat's Isovang is a tubular Hard (solid) Vang with integral sheaves and line that is Spring cushioned for Boom support. Commonly supplied with new boats, it is also a favorite addition to older boats with Isomat Spars. See: Isomat Isovangs. For Isomat Mast-mounted Brackets and Toggles to fit any Vang, See: Isomat Vang Brackets & Toggles.

Outhaul Cars Isomat Booms sometimes use an Outhaul Car that fits in its' integral Track, listed below. Note that Booms used with Furling Masts sometimes use upgraded Outhaul Systems with special Track and Ball-bearing Outhaul Cars, See: Sparcraft Booms for Furling Masts.
NB-40 Outhaul Car: NB2-17A: SS Outhaul Car Assembly rides on 4 delrin wheels. Car is attached to the mainsail with an 8mm (5/16") shackle, *NB2-2* (included), Outhaul pennant is attached to the shackle pin. Car is 85mm (3 3/8") long, replacement wheels are NB2-18W.
NB-40 Outhaul Car: NB2-18A: SS Outhaul Car Assembly is 92mm (3 5/8") long. Car rides on 4 delrin wheels and features a 12mm (7/16") clew attachment pin and a 10mm (3/8") pin for attachment of the outhaul pennant.
	NB-40 Outhaul Car Wheel: NB2-18W: Delrin Wheel for NB-40 Outhaul Cars is 19mm (3/4") OD x 10mm (3/8") wide x 10mm (3/8") ID.
	NB-40 Outhaul Car Axle: NB2-18X: SS Outhaul Car Axle is 10mm (3/8") OD x 24mm (15/16") long.

FB2 Outhaul Car, Short: FB2-18AS: Aluminum Outhaul Car Assembly is 100mm (4") long. Car rides on 4 Torlon rods to minimize friction, and features a 8mm (5/16") removable shackle for attachment of the clew and outhaul pennant.
	Torlon Rods for FB2 Short Outhaul Car: FB2-18ASR: Torlon Rod Set for Short FB2 Outhaul Car includes (4) 6.5mm Torlon rods x 100mm (4") long.
FB-2 Outhaul Slide, Long: FB2-18AL: Aluminum Outhaul Car Assembly is 150mm (6") long. Car rides on 4 Torlon rods to minimize friction, and features a 8mm (5/16") shackle for attachment of the clew and outhaul pennant. This item is no longer available and is shown here for identification only.
	Torlon Rods for FB-2 Long Outhaul Car: FB2-18ALR: Torlon Rod Set for Long FB-2 Outhaul Car includes (4) 6.5mm Torlon rods x 150mm (6") long.

NB-40 Outhaul Ass'y Complete: NB40-2A: Cast aluminum Outhaul Assembly incorporates provisions for internal outhaul and 3 internal reef lines. Sheaves and sheave axle slide in from the aft side simultaneously, and are held in place by the outhaul and/or reef lines. Rib on aft upper side allows for topping lift attachment.
	NB-40 Outhaul Casting: NB40-2: Replacement Casting only, for the NB-40 Outhaul Assembly. Casting extends (maximum) 3 1/8" (80mm) beyond tube end.
	NB2 Boom Sheave: NB2-10: Acetyl Sheave is 60mm (2 5/16") OD x 14mm (9/16") wide x 10mm (3/8") ID.
	NB2 Boom Sheave - Aluminum: NB2-10A: 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.
	Sheave Axle for NB-40 Outhaul: NB2-13: SS 'Drop-in' Sheave Axle pin is 10mm (3/8") diameter x 79mm (3 1/8") long.
NB-40 Outhaul End Plug: NB40-2EP: Black Plastic End Plug covers opening in back end of NB40-2 Outhaul Casting. New 'Bird Nest Buster' snaps into place, blocking the hole, but is easily removable for access to lines. If you've ever had a nesting problem, here's the solution.

Isomat NB-40 Boom Section Measurements (OD): 5 7/8" x 4 3/8" (150mm x 110mm) Wall Thickness: .112" (2.85mm) Weight/ft.: 2.71 lbs. Weight/M: 4.04 kg Moments of inertia: Ixx = 11.22", Iyy = 4.97" Moments of inertia: Ixx = 467cm4, Iyy = 207cm4 Circumference: 17 1/2" (445mm) Sail slides: 1/2" round slugs (A018, A118) or 1/2" boltrope Lower Track: 31mm x 4.5mm (1 7/32" x 5/32") Alloy: 6061-T6 Standard Lengths: 17' 1" (5.2M), 19' 8" (6M)* ml5990F51do5200 Common Boom usage: Bayfield 36, 40; Beneteau First 375S, 38, 405, 405S, 42*, 42S, 435; Cabo Rico; Comfortina 38;
CS 36, 40; Cal 39; Corbin 39; Endeavour 42; Express 34; Freedom 28, 30; Formosa 42, 43, 44, 46, 51^d; Gecco 39; Gozzard 36; Hunter 35, 37, 40, Passage 42; Island Packet 38; Jon 39; Kashing 47; Kirie Feeling 13.50; Maota 36, 42C, 42K, 46^d; Mason 43K (main); Morgan 41, 43; Northwind 40S; O'Day 39, 40; Omega 42; Pan Oceanic 38; Pearson 33, 36-2, 37; Tartan 40; Tayana 42, 45; Transworld 39, 41K^d; Vagabond 39, 42K, 47K; Whitby 42, 42C, 42K;

Isomat NB-40 Boom Section Isomat NB-40 Boom Section is stocked in a variety of lengths fully anodized. Sections can be ordered bare (unmachined), or cut to shorter lengths with or without milling for other components. Painted finishes and other lengths are available on special order. If you require a complete Boom Assembly, you can select from components below and contact us with specifications. If you require components not listed below please contact us with details. All NB-40 Boom Ends have provisions for 4 internal lines.

NB-40 Boom Components Although no other components have changed, the NB-40 Boom has been produced with 2 Different Gooseneck Arrangements. New-Style Goosenecks are listed below; Old-Style Goosenecks are listed separately. Old-Style NB-40 Gooseneck Assemblies and Parts. Note that some Booms have been produced with the Isomat AutoReef (single line) Reefing System, using specially modified Boom End castings. For details, See: Isomat AutoReef System.

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