Sailing Single Blocks
- Ronstan®20 Series Ball Bearing Shave Single Linked Block for 1/4" D Lines (RF20281)20 Series Ball Bearing Shave Single Linked Block for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If you’re an avid sailboat...Low frictionHigh static and dynamic load capacity$36.02
- Ronstan®20 Series Ball Bearing Shave Single Linked Block with Loop Head for 1/4" D Lines (RF20284)20 Series Ball Bearing Shave Single Linked Block with Loop Head for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If you’re an...Low frictionHigh static and dynamic load capacity$26.19
- Ronstan®20 Series Ball Bearing Shave Single Pivoting Lead Block for 1/4" D Lines (RF20174)20 Series Ball Bearing Shave Single Pivoting Lead Block for 1/4" D Lines by Ronstan®. Pivoting version suits controls that need to be trimmed from either side of the boat. Lead blocks are a low profile solution for leading halyards or...180 degree pivoting sheavePivoting version suits controls that need to be trimmed from either side of the boat$37.11
- Ronstan®20 Series Ball Bearing Shave Single Upright Lead Block for 1/4" D Lines (RF20171)20 Series Ball Bearing Shave Single Upright Lead Block for 1/4" D Lines by Ronstan®. If you’re an avid sailboat enthusiast looking to enhance your experience on the water, then top-quality sailing products offered on our virtual...Typically used for halyards at the mast baseGrade 316 stainless steel ball bearings$21.83
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Becket & Loop Head for 1/4" D Lines (RF20111)20 Series Ball Bearing Shave Single Utility Block with Becket & Loop Head for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. Can...Low frictionHigh static and dynamic load capacity$15.28
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Becket & Rivet Mount Head for 1/4" D Lines (RF20151A)20 Series Ball Bearing Shave Single Utility Block with Becket & Rivet Mount Head for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low...Low frictionHigh static and dynamic load capacity$20.73
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Cheek for 1/4" D Lines (RF20151)20 Series Ball Bearing Shave Single Utility Block with Cheek for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If you’re an...Low frictionHigh static and dynamic load capacity$16.37
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Cover Plate for 1/4" D Lines (RF20711)20 Series Ball Bearing Shave Single Utility Block with Cover Plate for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If you’re...Exit blocks minimise friction in lines passing through the deck or exiting masts and boomsGrade 316 stainless steel load straps$31.66
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Loop Head for 1/4" D Lines (RF20101)20 Series Ball Bearing Shave Single Utility Block with Loop Head for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. Can be fitted...Low frictionHigh static and dynamic load capacity$11.98
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Loop Mount for 1/4" D Lines (RF20184)20 Series Ball Bearing Shave Single Utility Block with Loop Mount for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If you’re...Low frictionHigh static and dynamic load capacity$19.09
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Stand-Up Head for 1/4" D Lines (RF20141)20 Series Ball Bearing Shave Single Utility Block with Stand-Up Head for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If...Low frictionHigh static and dynamic load capacity$20.73
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Swivel Hook for 1/4" D Lines (RF20180)20 Series Ball Bearing Shave Single Utility Block with Swivel Hook for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If you’re...Low frictionHigh static and dynamic load capacity$24.01
- Ronstan®20 Series Ball Bearing Shave Single Utility Block with Swivel Shackle for 1/4" D Lines (RF20100)20 Series Ball Bearing Shave Single Utility Block with Swivel Shackle for 1/4" D Lines by Ronstan®. Precision moulded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction. If...Low frictionHigh static and dynamic load capacity$20.98
- Ronstan®20 Series Orbitblock™ Ball Bearing Shave Single Utility Block with Becket & Dyneema Lashing for 1/4" D Lines (RF25109HL)20 Series Orbitblock™ Ball Bearing Shave Single Utility Block with Becket & Dyneema Lashing for 1/4" D Lines (RF25109HL) by Ronstan®. The incredible Series 20 Orbit Block™ is capable of loads up to 660 lb while weighing a mere 9...Leech / control linesCunninghams$73.44
- Ronstan®20 Series Orbitblock™ Ball Bearing Shave Single Utility Block with Becket & Dyneema Lashing for 1/4" D Lines (RF25109)20 Series Orbitblock™ Ball Bearing Shave Single Utility Block with Becket & Dyneema Lashing for 1/4" D Lines (RF25109) by Ronstan®. The incredible Series 20 Orbit Block™ is capable of loads up to 550 lb while weighing a mere 9...Leech / control linesCunninghams$13.98
- Ronstan®25 Series Acetal Sheave Single Utility Block with Becket & Loop Head for 1/4" D Lines (RF572)25 Series Acetal Sheave Single Utility Block with Becket & Loop Head for 1/4" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can...Lightweight durable constructionEconomical$19.09
- Ronstan®25 Series Acetal Sheave Single Utility Block with Loop Head for 1/4" D Lines (RF571)25 Series Acetal Sheave Single Utility Block with Loop Head for 1/4" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be fitted...Lightweight durable constructionEconomical$12.00
- Ronstan®25 Series Acetal Sheave Single Utility Block with Swivel Ring for 1/4" D Lines (RF2332)25 Series Acetal Sheave Single Utility Block with Swivel Ring for 1/4" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be...Lightweight durable constructionEconomical$25.11
- Ronstan®25 Series Acetal Sheave Single Utility Block with Swivel Shackle for 1/4" D Lines (RF573)25 Series Acetal Sheave Single Utility Block with Swivel Shackle for 1/4" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be...Lightweight durable constructionEconomical$19.09
- Ronstan®30 Series 10 mm High Load Exit Box for 3/8" D Single Rope or 3/16" D Wire (RF41712)30 Series 10 mm High Load Exit Box for 3/8" D Single Rope or 3/16" D Wire by Ronstan®. Ronstan manufactures an extensive range of sheave boxes for use with rope and wire. Plain bearing sheaves are ideal for halyards and other...Nylatron® sheaveGrade 316 stainless steel cheeks$33.84
- Ronstan®30 Series Acetal Sheave Single Block with Curved Base & Tube Rivet Head for 5/16" D Lines (RF285)30 Series Acetal Sheave Single Block with Curved Base & Tube Rivet Head for 5/16" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. If you’re an avid sailboat...Lightweight durable constructionEconomical$24.34
- Ronstan®30 Series Acetal Sheave Single Block with Loop Head for 5/16" D Lines (RF280)30 Series Acetal Sheave Single Block with Loop Head for 5/16" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be fitted with...Lightweight durable constructionEconomical$10.90
- Ronstan®30 Series Acetal Sheave Single Fiddle Block with Tube Rivet Head for 5/16" D Lines (RF186)30 Series Acetal Sheave Single Fiddle Block with Tube Rivet Head for 5/16" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be...Lightweight durable constructionEconomical$29.80
- Ronstan®30 Series Acetal Sheave Single Fiddle Block with V-Jam Cleat & Tube Rivet Head for 5/16" D Lines (RF187)30 Series Acetal Sheave Single Fiddle Block with V-Jam Cleat & Tube Rivet Head for 5/16" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block...Lightweight durable constructionEconomical$34.39
- Ronstan®30 Series Acetal Sheave Single Utility Block with Becket & Ferrule Eye for 3/8" D Lines (RF470)30 Series Acetal Sheave Single Utility Block with Becket & Ferrule Eye for 3/8" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads...Lightweight durable constructionEconomical$25.61
- Ronstan®30 Series Acetal Sheave Single Utility Block with Becket & Loop Head for 5/16" D Lines (RF681)30 Series Acetal Sheave Single Utility Block with Becket & Loop Head for 5/16" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can...Lightweight durable constructionEconomical$17.14
- Ronstan®30 Series Acetal Sheave Single Utility Block with Becket & Swivel Shackle for 3/8" D Lines (RF567)30 Series Acetal Sheave Single Utility Block with Becket & Swivel Shackle for 3/8" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads...Lightweight durable constructionEconomical$32.74
- Ronstan®30 Series Acetal Sheave Single Utility Block with Becket & Tube Rivet Head for 5/16" D Lines (RF188)30 Series Acetal Sheave Single Utility Block with Becket & Tube Rivet Head for 5/16" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance.Hollow rivets accept fixing...Lightweight durable constructionEconomical$19.25
- Ronstan®30 Series Acetal Sheave Single Utility Block with Ferrule Eye Head for 3/8" D Lines (RF469)30 Series Acetal Sheave Single Utility Block with Ferrule Eye Head for 3/8" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be...Lightweight durable constructionEconomical$20.06
- Ronstan®30 Series Acetal Sheave Single Utility Block with Swivel Ring for 3/8" D Lines (RF443)30 Series Acetal Sheave Single Utility Block with Swivel Ring for 3/8" D Lines by Ronstan®. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be...Lightweight durable constructionEconomical$27.99
Blocks are essential devices in sailing. Essentially, a block is a pulley; typically, it consists of a frame containing a grooved wheel that can accommodate a line. Assemblies with only one wheel or sheave are called single blocks. You can find them all over a sailboat; they are used to lift loads or maneuver sheets with minimal friction regardless of which direction the rope moves in. They can also be used in combination. Single sailing blocks can be made of different materials, including metal, wood, and plastic. Typically, their names imply their function.
For example, there are fiddle, linked, shock, spinnaker, utility, and simple sheave blocks, among other types. On our virtual shelves, we have selected a broad choice of quality single sailing blocks to fit every type of vessel. The features defining the blocks include the line diameter, sheave type, maximum load, and other specific characteristics. Depending on the purpose and task, there are blocks with a back plate, becket, snap shackle, and swivel fork, among others. We offer exclusive products made by trusted companies, tested to meet or exceed industry standards, and built to deliver performance and long-lasting efficiency.