Exit Blocks

Exit Blocks, or Sheave Boxes, incorporate a sheave (or two), and are used to exit any internal control line (halyards, pole lifts, centerboard pennants, etc.) where a directional change of 90 to 180 degrees is required - as opposed to Exit Plates where there is no directional change. Most Exit Blocks feature an interior cross-bar to captivate the line and prevent it from jumping off of the sheave. Exit Blocks listed here are commonly used in Spar applications, but some are suitable for a variety of other uses as thru-deck blocks, centerboard pennants, etc.. Exit Blocks are listed here generally by the size of the sheave they use in ascending order. Wire Exit Blocks are designed primarily for use with wire, but are well suited for modern high modulus lines. Other Exit Blocks are available for replacement or exact matching purposes. Depending on the kind of spars you have, See also: Kenyon Exit Blocks, Isomat Exit Blocks, or Z-Spar Exit Blocks. Replacement Sheaves are available for some Exit Blocks. Take Sheave measurements, and See: Sheaves. See also: other Blocks, and See Exit Plates (Halyard Exits) for in-line exit applications. Single Exit Blocks Double Exit Blocks Wire Exit Blocks

Single Exit Blocks
*Flat-mount SS Exit Block w/ 1 1/8" x 3/8" Sheave: RF 458X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheave is 1 1/8" OD x 3/8" wide with rope groove for up to 5/16" line. Assembly fits in cutout 1 3/4" long x 9/16" wide and projects 1" internally from mounting surface. Flat top is 1 3/4" long x 1 1/2" wide, and mounts with (6) #10 (3/16") fasteners on 5/8" x 1 1/16" wide centers.
*Flat-mount SS Exit Block w/ 1" x 7/16" Sheave: RF 462X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheave is 1" OD x 7/16" wide with rope groove for up to 3/8" line. Assembly fits in cutout 1 3/4" long x 5/8" wide and projects 1" internally from mounting surface. Flat top is 1 3/4" long x 1 5/8" wide, and mounts with (6) #10 (3/16") fasteners on 5/8" x 1 3/16" wide centers.
*Flat-mount SS Exit Block w/ 7/8" x 7/16" Aluminum Sheave: K-152W:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for centerboard pennant. Aluminum sheave (K-198-3.5A) is 7/8" OD x 7/16" wide with wire/rope V-groove for up to 3/8" line and 1/8" wire. Assembly fits in cutout 1 1/2" long x 5/8" wide and projects 3/4" internally from mounting surface. Flat top plate is 2 15/16" long x 15/16" wide, and mounts with (2) #10 (3/16") FH screws on 2 7/16" centers.

*SS Exit Block w/ 1 1/2" Sheave: K-11110P:* Stainless Steel Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Plastic sheave (K-199-4B) is 1 1/2" diameter x 15/32" wide and will handle line up to 3/8" diameter. Assembly fits in mast cutout 1 3/4" high x 11/16" wide and projects 1 7/8" inside of mast. Mounting flanges are 1 3/4" long x 1 15/16" wide, and are at 90 degrees to the sheave for use on flat surfaces; flanges can also be bent to fit a variety of curved surfaces. Assembly is mounted with (4) #10 (3/16") fasteners on 1 5/16" (vertical) x 1 7/16" (horizontal) hole centers.
*SS Exit Block w/ 1 1/2" x 3/8" Aluminum Sheave: K-11110A:* Stainless Steel Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Aluminum sheave (K-10545-1) is 1 1/2" diameter x 3/8" wide and will handle 1/8" wire, or rope up to 5/16" diameter. Assembly fits in mast cutout 1 3/4" high x 9/16" wide and projects 1 7/8" inside of mast. Mounting flanges are 1 3/4" long x 1 15/16" wide, and are at 90 degrees to the sheave for use on flat surfaces; flanges can also be bent to fit a variety of curved surfaces. Assembly is mounted with (4) #10 (3/16") fasteners on 1 5/16" (vertical) x 1 7/16" (horizontal) hole centers.
*SS Exit Block w/ 1 1/2" Aluminum Sheave: K-11110A-1:* As K-11110A, above, but mounting flanges already angled for use on curved surfaces. Flanges can be bent more or less, to fit a variety of curved surfaces. Unit now features removable sheave.
*SS Exit Block w/ 1 1/2" Aluminum Sheave: K-11110A-2:* As K-11110A-1, above, but mounting flanges angled severely for use as Main Halyard Sheave Box on the 2040 Mast Section.
*Exit Block w/ 1 1/2" Sheave: NGA-25:* *Exit Block w/ 1 1/2" Aluminum Sheave: NGA-25A:* Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Black Plastic block assembly has removable 8mm (5/16") SS Sheave Axle. Plastic sheave is 38mm (1 1/2") diameter x 31/64" wide for rope up to 3/8" diameter. Block measures 4 1/8" long x (maximum) 1 1/16" wide and projects 1" inside of mast. Assembly fits in mast cutout 2 3/4" high x 15/16" wide, and is mounted with (2) #10 (3/16") FH fasteners on 3 3/16" (81mm) hole centers. The Aluminum Sheave version *NGA-25A* is as *NGA-25*, but with Aluminum Sheave.

*Aluminum Exit Block w/ 1 3/4" Aluminum Sheave: K-1555:* Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Welded aluminum block assembly is finished with black epoxy coating. Aluminum sheave (K-198-7A) is 1 3/4" diameter x 31/64" wide and will handle 3/16" wire, or rope up to 7/16" diameter. Assembly fits in mast cutout 2 1/4" high x 3/4" wide and projects 2" inside of mast. Mounting flange is 3 1/4" long x 1 1/2" wide, and slightly curved to fit a variety of mast surfaces. Assembly is mounted with (4) #10 (3/16") fasteners on 2 7/8" (vertical) x 1 1/8" (horizontal) hole centers. As used on some J/24’s.
*SS Exit Block w/ 1 7/8" Sheave: K-11199P:* Stainless Steel Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Plastic sheave (K-8850) is 1 7/8" diameter x 9/16" wide and will handle line up to 7/16" diameter. Assembly fits in mast cutout 2 3/8" high x 13/16" wide and projects 2 1/4" inside of mast. Mounting flanges are 2 3/8" long x 2" wide, and are at 90 degrees to the sheave for use on flat surfaces; flanges can also be bent to fit a variety of curved surfaces. Assembly is mounted with (4) #10 (3/16") fasteners on 1 7/8" (vertical) x 1 1/2" (horizontal) hole centers.
*SS Exit Block w/ 1 7/8" Sheave: K-11199P-1:* As K-11199P, above, but mounting flanges already angled for use on curved surfaces. Flanges can be bent more or less, to fit a variety of curved surfaces.

*SS Exit Block w/ 2" Aluminum Sheave: K-11199A:* Stainless Steel Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Aluminum sheave (K-10861-1) is 2" diameter x 9/16" wide and will handle 3/16" wire, or rope up to 1/2" diameter. Assembly fits in mast cutout 2 3/8" high x 13/16" wide and projects 2 1/4" inside of mast. Mounting flanges are 2 3/8" long x 2" wide, and are at 90 degrees to the sheave for use on flat surfaces; flanges can also be bent to fit a variety of curved surfaces. Assembly is mounted with (4) #10 (3/16") fasteners on 1 7/8" (vertical) x 1 1/2" (horizontal) hole centers. Unit now features removable sheave.
*SS Exit Block w/ 2" Aluminum Sheave: K-11199A-1:* As K-11199A, above, but mounting flanges already angled for use on curved surfaces. Flanges can be bent more or less, to fit a variety of curved surfaces. Unit now features removable sheave.
*SS Exit Block w/ 1 3/4" x 1/2" Sheave: RF 460X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheaves are 1 3/4" OD x 1/2" wide with rope groove for up to 3/8" line. Assembly fits in cutout 2 1/2" long x 5/8" wide and projects 1 5/8" internally from mounting surface. Flat top is 2 1/2" long x 1 3/4" wide, and mounts with (6) #10 (3/16") fasteners on 1" x 1 1/4" wide centers. Unit now features removable sheave.
*SS Exit Block w/ 2" x 3/4" Sheave: RF 460W:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Heavy-duty Nylatron Sheave is 2" OD x 3/4" wide with groove for up to 1/2" line or 3/16" wire. Assembly fits in cutout 2 1/2" long x 7/8" wide and projects 1 5/8" internally from mounting surface. Flat top is 2 1/2" long x 2" wide, and mounts with (6) #10 (3/16") fasteners on 1" x 1 1/2" wide centers. As RF 460X, but wider.
*Aluminum Exit Block w/ 2" Sheave: NGA-26:* *Aluminum Exit Block w/ 2" Aluminum Sheave: NGA-26A:* Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Cast Aluminum block assembly has removable 10mm (3/8") SS Sheave Axle. Acetyl Sheave (NG1-3) is 50mm (2") OD x 14.5mm (9/16") wide for rope up to 1/2" diameter. Block measures 4 1/2" (115mm) long x 1 3/8" (35mm) wide and projects 1 7/16" (36mm) inside of mast. Assembly fits in mast cutout 2 13/16" (72mm) high x 15/16" (24mm) wide, and is mounted with (2) 1/4" (6mm) fasteners on 3 5/8" (92mm) hole centers. The stronger Aluminum Sheave version *NGA-26A* is as *NGA-26, but with Aluminum Sheave NG1-3A*.
*SS Exit Block w/ 2" Aluminum Sheave: Sch 34-35:* Stainless Steel Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Aluminum V-groove sheave is 2" diameter x 9/16" wide and will handle 3/16" wire, or rope up to 1/2" diameter. Assembly fits in mast cutout 2 3/4" high x 13/16" wide and projects 2 1/4" inside of mast. Mounting flanges are 2 3/4" long x 2 1/2" wide, and are bent to fit a curved surface. Block is mounted with (6) #10 (3/16") fasteners.

*SS Exit Block w/ 2 1/4" x 5/8" Sheave: RF 461X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheave is 2 1/4" OD x 5/8" wide with rope groove for up to 1/2" line. Assembly fits in cutout 3" long x 3/4" wide and projects 2" internally from mounting surface. Flat top is 3" long x 1 7/8" wide, and mounts with (6) #10 (3/16") fasteners on 1 1/4" x 1 3/8" wide centers.
*SS Exit Block w/ 2 3/8" Aluminum Sheave: Sch 34-32:* Stainless Steel Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Aluminum V-groove sheave is 2 3/8" diameter x 3/4" wide and will handle 5/8" line, or wire up to 7/32" diameter. Assembly fits in mast cutout 2 7/8" high x 1" wide and projects 2 3/4" inside of mast. Mounting flanges are 2 7/8" long x 2 1/2" wide, and are bent to fit a curved surface. Block is mounted with (6) #10 (3/16") fasteners.
*SS Exit Block w/ 2 3/8" Aluminum Sheave: Sch 34-32FR:* Stainless Steel Exit Block is as Sch 34-32, above, but for mounting on flat surfaces, and has a Rope groove. Aluminum sheave with Rope groove is 2 3/8" diameter x 3/4" wide and will handle 5/8" (16mm) line. Assembly fits in mast cutout 2 7/8" high x 1" wide and projects 2 3/4" inside of mast. Mounting flanges are 2 7/8" long x 2 1/2" wide, and are at 90 degrees to the sheave for use on flat surfaces. Block is mounted with (6) #10 (3/16") fasteners.
*SS Exit Block w/ 2 1/2" x 3/4" Aluminum Sheave: RF 461ARX:*
Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Aluminum Sheave is 2 1/2" OD x 3/4" wide with groove for up to 9/16" (13mm) line or 1/4" wire. Assembly fits in cutout 3" long x 7/8" wide and projects 2" internally from mounting surface. Flat top is 3" long x 2" wide, and mounts with (6) #10 (3/16") fasteners on 1 1/4" x 1 1/2" wide centers.

*Aluminum Exit Block w/ 3 3/8" Sheave: NGA-27:* *Aluminum Exit Block w/ 3 3/8" Delrin Sheave: NGA-27D:* Large Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Cast Aluminum block assembly has lightweight tubular 22mm (7/8") SS Sheave Axle. Acetyl Sheave (NG2-4) is 85mm (3 3/8") OD x 20mm (3/4") wide for rope up to 5/8" diameter. Block measures 6 1/4" (160mm) long x 1 5/8" (41mm) wide and projects 2 7/8" (72mm) inside of mast. Assembly fits in mast cutout 4 1/2" (115mm) high x 1 1/4" (32mm) wide, and is mounted with (2) 1/4" (6mm) fasteners on 5 3/8" (136mm) hole centers. Stronger Delrin Sheave version uses NG2-4D Sheave. As used on Beneteau First 40.7. 503

Double Exit Blocks
Double Exit Blocks have 2 Sheaves side by side, and are commonly used for halyards, spinnaker pole lifts and other control lines on the Mast, as well as thru-deck blocks. Double Exit Blocks with alloy Sheaves designed for use with wire and small diameter lines are listed separately, See: Wire Exit Blocks.
*Double Exit Block w/ 1 1/8" x 3/8" Sheaves: RF 1194X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheaves are 1 1/8" OD x 3/8" wide with rope groove for up to 5/16" line. Assembly fits in cutout 1 3/4" long x 1" wide and projects 1" internally from mounting surface. Flat top is 1 3/4" long x 2" wide, and mounts with (6) #10 (3/16") fasteners on 5/8" x 1 9/16" wide centers.
*Double Exit Block w/ 1" x 7/16" Sheaves: RF 1195X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheaves are 1" OD x 7/16" wide with rope groove for up to 3/8" line. Assembly fits in cutout 1 3/4" long x 1" wide and projects 1" internally from mounting surface. Flat top is 1 3/4" long x 2 1/8" wide, and mounts with (6) #10 (3/16") fasteners on 5/8" x 1 11/16" wide centers. mmm
*Double Exit Block w/ 1 1/2" x 3/8" Sheaves: RF 1196X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheaves are 1 1/2" OD x 3/8" wide with rope groove for up to 5/16" line. Assembly fits in cutout 2 1/8" long x 1" wide and projects 1 1/4" internally from mounting surface. Flat top is 2 1/8" long x 2" wide, and mounts with (6) #10 (3/16") fasteners on 13/16" x 1 9/16" wide centers. S251x
*Double Exit Block w/ 1 3/4" x 1/2" Sheaves: RF 1197X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used for halyards, spinnaker pole lifts and other internal control lines. Delrin Sheaves are 1 3/4" OD x 1/2" wide with rope groove for up to 7/16" line. Assembly fits in cutout 2 1/2" long x " wide and projects 1 5/8" internally from mounting surface. Flat top is 2 1/2" long x " wide, and mounts with (6) #10 (3/16") fasteners on 1" x " wide centers. As used on Kirby 25 Mast, and others.	MMM

Dual Sheave Exit Block w/ 1" x 7/16" Aluminum Sheaves: K-1159: Stainless Steel Dual Sheave Exit Block is used for halyards, spinnaker pole lifts and other internal control lines. Aluminum sheaves (K-198-4A) are 1" diameter x 7/16" wide with wire/rope V-groove for up to 3/8" line and 1/8" wire. Black anodized, welded aluminum block assembly fits in mast cutout 1 5/8" high x 1 3/8" wide and projects 1 3/8" inside of mast. Mounting flange is 2 1/2" long x 2 1/8" wide plate, slightly curved to fit a variety of mast surfaces. Assembly is mounted with (4) #10 (3/16") fasteners on 2 1/8" (vertical) x 1 3/4" (horizontal) hole centers. Frequently used on sides of Mast (near base) for halyard exits.
Dual Sheave Exit Block w/ 1 7/16" x 1/2" Sheaves: SP-911: Stainless Steel Dual Sheave Exit Block was designed specifically for the Cape Dory Typhoon, where it is installed at the base of the mast, to lead main & jib halyards aft to the cockpit. Although formed to fit the Spartan CD-2 section, this unit can be used for halyards and other control lines on other sections as well. Flanges can also be bent to fit a variety of curved surfaces. Phenolic sheaves measure 1 7/16" x 1/2", and will handle wire or rope up to 3/8" diameter. Assembly fits in mast cutout 2" long x 1 3/8" wide, and fastens with (6) #10 (3/16") fasteners. Sch 34-29X
Dual Sheave Exit Block w/ 2" x 5/8" Aluminum Sheaves: Sch 34-36: Stainless Steel Dual Sheave internal Exit Block designed to fit a variety of larger Mast and Boom Sections. Heavy-duty Block is suitable for halyards and other high-load applications. Flanges can be bent to fit a variety of curved surfaces. Aluminum sheaves are 2" OD x 5/8" wide, with wire/rope V-groove for up to 1/2" line and up to 1/8" wire. Assembly fits in mast cutout 2 3/4" long x 1 1/2" wide, and fastens with (6) #10 (3/16") fasteners.

Wire Exit Blocks
These Exit Blocks are designed for use with wire, but can be used with appropriately sized line. All have metal Sheaves. Units with Flat top plates are commonly used as thru-deck blocks, or for centerboard pennants.
*SS Exit Block w/ 1" Sheave for 1/16" Wire: K-154S:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used as a thru-deck block. Unit has 1" OD x 1/8" wide SS sheave for 1/16" wire. Assembly fits in cutout 1" long x 1/4" wide and projects 1 1/4" internally from mounting surface. Flat top plate is 2 9/16" long x 15/16" wide, and mounts with (2) #10 (3/16") FH screws on 1 15/16" centers.

*SS Exit Block w/ 7/8" Sheave for 3/32" Wire: RF 453X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used as a thru-deck block. Unit has 7/8" OD x 5/32" wide Bronze sheave for 3/32" wire. Assembly fits in cutout 1" long x 5/16" wide and projects 1 1/8" internally from mounting surface. Sheave is flush with top, unit is 1" long x 1 1/2" wide, and mounts with (4) #10 (3/16") RH fasteners on 5/8" long x 1 1/8" wide centers.
*SS Exit Block w/ 7/8" Sheave for 3/32" Wire: RF 452X:* Stainless Steel Exit Block is designed for mounting on a slightly curved surface. Unit has 7/8" OD x 5/32" wide Bronze sheave for 3/32" wire. Assembly fits in cutout 1" long x 5/16" wide and projects 1" internally from mounting surface. Sheave projects 1/8" above top, unit is 1" long x 1/8" wide, and mounts with (4) #10 (3/16") RH fasteners on 5/8" long x 25/32" wide centers.

*SS Exit Block w/ 1" Sheave for 1/8" Wire: K-154:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used as a thru-deck block. Unit has 1" OD x 1/4" wide SS sheave for up to 1/8" wire. Assembly fits in cutout 1" long x 1/4" wide and projects 1 1/4" internally from mounting surface. Flat top plate is 2 9/16" long x 15/16" wide, and mounts with (2) #10 (3/16") FH screws on 1 15/16" centers.
*SS Exit Block w/ 1" Sheave for 1/8" Wire: K-154C:* As K-154, above, but with curved mounting surface for use on front of spar, and commonly used as a pole lift block. Unit has 1" OD x 1/4" wide SS sheave for up to 1/8" wire. Assembly fits in cutout 1" long x 1/4" wide and projects 1 1/4" internally from mounting surface. Top plate is 2 9/16" long x 15/16" wide, and mounts with (2) #10 (3/16") FH screws on 1 15/16" centers.

*SS Exit Block w/ 1" Sheave for 3/16" Wire: RF 454X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used as a thru-deck block. Unit has 1" OD x 1/4" wide SS sheave for up to 3/16" wire. Assembly fits in cutout 1 3/4" long x 3/8" wide and projects 1" internally from mounting surface. Flat top is 1 3/4" long x 1 3/8" wide, and mounts with (6) #10 (3/16") fasteners on 5/8" x 15/16" wide centers.
*Double SS Exit Block w/ 1" Sheaves for 3/16" Wire: RF 1190X:* Double Exit Block is as *RF 454X, above, but with 2 Sheaves. Assembly fits in cutout 1 3/4" long x 3/4" wide and projects 1" internally from mounting surface. Flat top is 1 3/4" long* x 1 11/16" wide, and mounts with (6) #10 (3/16") fasteners on 5/8" x 1 1/4" wide centers.
*SS Exit Block w/ 1 1/2" Sheave for 3/16" Wire: RF 455X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used as a thru-deck block. Unit has 1 1/2" OD x 1/4" wide SS sheave for up to 3/16" wire. Assembly fits in cutout 2 1/8" long x 3/8" wide and projects 1 1/4" internally from mounting surface. Flat top is 2 1/8" long x 1 3/8" wide, and mounts with (6) #10 (3/16") fasteners on 13/16" x 15/16" wide centers.
*Double SS Exit Block w/ 1 1/2" Sheaves for 3/16" Wire: RF 1191X:* Double Exit Block is as *RF 455X, above, but with 2 Sheaves. Assembly fits in cutout 2 1/8" long x 3/4" wide and projects 1 1/4" internally from mounting surface. Flat top is 2 1/8" long* x 1 11/16" wide, and mounts with (6) #10 (3/16") fasteners on 13/16" x 1 1/4" wide centers.
*SS Exit Block w/ Removable 1 3/4" Sheave for 3/16" Wire: NF 10310:*
Stainless Steel Exit Block features Removable Sheave for wire. Unit is riveted as conventional Exit blocks, but sheave axle is a 1/4" bolt with locknut so wire can be installed or removed without cutting. Chromed bronze sheave is 1 3/4" diameter x 5/16" wide and will handle up to 3/16" wire or rope. Assembly fits in cutout 2 1/2" long x (minimum) 7/16" wide and projects 1 1/2" internally from mounting surface. Mounting flanges are 2 1/2" long x 5/8" wide, and are slightly bent to fit a variety of curved surfaces. Assembly mounts with (6) #10 (3/16") fasteners on 7/8" x 1 1/16" wide centers. mil

*SS Exit Block w/ 1 3/4" Sheave for 7/32" Wire: RF 456X:* Stainless Steel Exit Block is designed for mounting on flat surface, and commonly used as a thru-deck block. Unit has 1 3/4" OD x 3/8" wide SS sheave for up to 7/32" wire. Assembly fits in cutout 2 1/2" long x 9/16" wide and projects 1 5/8" internally from mounting surface. Flat top is 2 1/2" long x 1 1/2" wide, and mounts with (6) #10 (3/16") fasteners on 1" x 1 3/32" wide centers.

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