40mm Carbo Air® Stand-up Block, Fixed
Mouse Over to Zoom
Click to Enlarge

HARKEN40mm Carbo Air® Stand-up Block, Fixed


In stock online.
Model # 1171586 | Mfg # 2652UPC # 97653090236


40mm Carbo Air® Stand-up Block, Fixed

Name Value
Ball Bearings Plastic
Becket No Becket
Diameter 3/8 Inch or 10 mm
Direction Any
Integral Cleat No Integral Cleat
Length 2 3/4 Inches
Mount Type Mechanical Fasteners
Ratchet Non Ratcheting
Safe Working Load 485 Pounds
Sheave Diameter 40 mm
Type Single Pivoting
Weight 1.7 Ounces

Product Overview

Harken 40mm Carbo Air® Stand-up Block with spring to construct a 2:1 or 3:1 purchase. 

Low-friction Carbo AirBlocks® are lightweight, strong, reliable—and economical. Consistently 30% lighter and 60% stronger than equivalent Classic blocks. The sideplates are UV-stabilized, high-strength resin and designed for small-diameter lines favored by racers. Good for jib and mainsheet systems on high-performance dinghies, and for high-load control lines on small keelboats.

Recipient of both the Dame Award and Sail Magazine’s Freeman-Pittman Award for innovation, this innovative line of blocks turns fiber-reinforced composite construction into a reliable strength-to-weight ratio you can depend on. Companions to the popular Harken Black Magic block line, these small, compact blocks work well with very high working loads for easy trimming.

Key Features

  • High strength-to-weight ratio block
  • Harken’s most innovative blocks
  • 30% lighter, 60% stronger than equivalent conventional blocks
  • Smaller block for jib and mainsheet systems on high-performance dinghies 
  • Use for high-load control lines on small keelboats
  • Stainless steel swivel shackle
  • Sheave Diameter: 1 9/16" (40 mm)
  • Max. Line Diameter: 3/8" (10 mm)
  • Max. Working Load (MWL): 485 lb. (220 kg) 
  • Breaking Load: 1620 lb. (735 kg)
  • Weight: 1.7 oz. (48 g) 
  • Length: 2 3/4" (70 mm)


The West Advisor articles have answered boaters' questions and provided solutions to boating problems for more than 20 years. West Marine has compiled one of the Web's most comprehensive collections of technical boating information articles.

Related West Advisor Articles


Product Q & A