Isomat Sheaves & Rollers

Isomat uses a variety of Acetyl (hard plastic) Sheaves in their Mast and Boom applications. Sheaves have a groove for rope or wire. These Sheaves are sufficiently strong to be used with wire halyards, as they are in Europe. Anodized Aluminum Sheaves are manufactured in the U.S., for high load applications and for their greater longevity. The most common Sheaves are listed below, but, as always, there are many "Specials". All Isomat Sheaves run directly on a SS axle. Delrin Reduction Bushings are available for some Sheaves.
Rollers are sheaves without a groove, and are used in a limited number of small-diameter applications. Sheaves and Rollers are listed by size, and by common application.

Part #	OD	Width	ID	Material
NG1-5R, NB1-11R151204	18mm (11/16")	15mm (5/8")	10mm (3/8")	Delrin (Roller)
NB1-20R	22mm (7/8")	15mm (9/16")	10mm (3/8")	Delrin (Roller)
NB1-10 661217	30mm (1 3/16")	10mm (3/8")	10mm (3/8")	Acetyl
NB1-10A	30mm (1 3/16")	10mm (3/8")	10mm (3/8")	Aluminum
NB2-20R	35mm (1 3/8")	15mm (9/16")	10mm (3/8")	Delrin (Roller)
NG1-3 661216	50mm (2")	14.5mm (9/16")	10mm (3/8")	Acetyl
NG1-3A	50mm (2")	14.5mm (9/16")	10mm (3/8")	Aluminum
NG1-4, NB2-10 15	60mm (2 5/16")	14.5mm (9/16")	10mm (3/8")	Acetyl
NG1-4A, NB2-10A	60mm (2 5/16")	14.5mm (9/16")	10mm (3/8")	Aluminum
NG1-4NS	60mm (2 5/16")	6mm (1/4")	10mm (3/8")	Stainless Steel

NB2-19R	22mm (7/8")	15mm (9/16")	10mm (3/8")	Delrin (Roller)
NB2-20R	35mm (1 3/8")	15mm (9/16")	10mm (3/8")	Delrin (Roller)
NG2-3B	85mm (3 3/8")	15mm (5/8")	10mm (3/8")	Acetyl
NG2-3AB	85mm (3 3/8")	15mm (5/8")	10mm (3/8")	Aluminum
NG2-3 661214	85mm (3 3/8")	15mm (5/8")	21.5mm (7/8")	Acetyl
NG2-3A	85mm (3 3/8")	15mm (5/8")	21.5mm (7/8")	Aluminum
NGS2-18 661218	85mm (3 3/8")	20mm (3/4")	16mm (5/8")	Acetyl
NGS2-19 661219	85mm (3 3/8")	20mm (3/4")	22mm (7/8")	Acetyl


Isomat Sheaves & Rollers by Application
Mast Sheaves & Rollers
NG 1 Masthead			Part #
	11/16" OD (18mm)	Forward Roller for Spinnaker Halyard	NG1-5
	2" OD (50mm)	Acetyl	NG1-3
	2" OD (50mm)	Aluminum	NG1-3A
	2 5/16" OD (60mm)	Acetyl	NG1-4
	2 5/16" OD (60mm)	Aluminum	NG1-4A

NG 2 Masthead
	3 3/8" OD (85mm)	Acetyl 21.5mm (7/8") ID (6 pieces maximum)	NG2-3
	3 3/8" OD (85mm)	Aluminum 21.5mm (7/8") ID	NG2-3A

NG 1 Cast Fractional Jib Box
	2 5/16" OD (60mm)	Acetyl Sheave (1 or 2 required)	NG1-4
	2 5/16" OD (60mm)	Aluminum Sheave	NG1-4A
	2 5/16" OD (60mm)	Stainless Steel Narrow Lower Sheave - 1/4" wide (2 required)	NG1-4NS
NG 2 Cast Fractional Jib Box
	3 3/8" OD (85mm)	Acetyl 5/8" ID / 3/4" wide	NGS2-18

NG 1 Welded Mast Base Sheave Box
	2 5/16" OD (60mm)	Acetyl	NG1-4
	2 5/16" OD (60mm)	Aluminum	NG1-4A
NG 2 Welded Mast Base Sheave Box
	3 3/8" OD (85mm)	Acetyl 10mm ID	NG2-3B
	3 3/8" OD (85mm)	Aluminum 10mm ID	NG2-3AB

Boom Sheaves & Rollers
NB 16, NB 26 Booms			Part #
	11/16" OD (18mm)	Gooseneck and Outboard Roller (3 forward, 2 aft)	NB1-11
	1 3/16" OD (30mm)	Acetyl Outhaul Sheave (1 required aft)	NB1-10
	1 3/16" OD (30mm)	Aluminum Outhaul Sheave	NB1-10A
	7/8" OD (22mm)	Delrin (Shuttle Block Roller)	NB1-20R

NB 32, NB 40, NB 55 Booms
	2 5/16" OD (60mm)	Acetyl (all sheaves, 4 in each end)	NB2-10
	2 5/16" OD (60mm)	Aluminum	NB2-10A
	1 3/8" OD (35mm)	Delrin (AutoReef / Shuttle Block Roller)	NB2-20R
	7/8" OD (22mm)	Delrin (AutoReef Roller)	NB2-19R

Isovang Sheaves

NG 1 Isovang 2" OD (50mm) Acetyl (2 per end)	NG1-3

NG 2 Isovang 3 3/8" OD (85mm) Acetyl - 3/4" wide (2 per end)	NGS2-19

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