Harken 16mm Air Block Pulleys
The Harken 16mm Air Block is an ultra-compact, lightweight pulley designed for small-diameter synthetic control lines where minimal weight and efficient operation are important. As Harken’s smallest block, its 16mm sheave and high strength-to-weight ratio make it well suited for performance dinghies and other compact rigging systems. A patented bearing system uses stainless steel ball bearings running in a captive grooved race to provide smooth, dependable operation under load.
Despite its small size, the 16mm Air Block is rated for a maximum working load of 250 lb. A polished 316 stainless steel top strap provides a durable attachment point for marine environments, while the block accommodates line up to 5mm in diameter. Applications include dinghy control lines, leech lines, downhauls, traveler controls, spinnaker pole trip lines, outhauls, cunninghams, and halyards on prams.
| Model | Sheave in. | Length in. | Weight oz. | Maximum Line | Max Working Load lb. | Breaking Load lb. |
| 404F | 5/8 in | 1 1/8 | 0.33 | 7/32 in | 250 | 1200 |
| 417F | 5/8 in | 1 13/16 | 0.63 | 7/32 in | 250 | 750 |
| 406F | 5/8 in | 1 11/16 | 94 | 7/32 in | 450 | 1200 |
| 408F | 5/8 in | 1 13/16 | 1.44 | 7/32 in | 700 | 1200 |