
Shop / Tools & WorkshopLewmar
Lewmar 50mm Synchro Single Block 29925001BK Swivel Shackle 990lb
$47.99
Out of stock - check back soonFrom the entry
Brand new in original packaging.
- Genuine Lewmar 50mm Synchro Single Block, MPN 29925001BK, UPC 743683203749 - identity confirmed across OEM and two independent retailers.
- Free-Spin plain-bearing sheave delivers low-friction, efficient line handling comparable to ball-bearing blocks.
- Tool-free sliding mechanism lets you select full 360° free rotation or lock the swivel head at 0° or 90° to the sheave axle.
- Self-aligning head allows up to 30° of float in the locked setting to reduce line wear.
- Rated for a Safe Working Load of 990 lb and compatible with 1/4 in - 3/8 in (6mm-10mm) line.
- Built with a stainless steel shackle post and framework supporting glass-fiber-reinforced cheeks for strength with minimal weight.
- Versatile workhorse block suited for halyard turning blocks, mainsheet systems, and masthead applications; used as standard equipment on many racer/cruiser sailboats.
Specifications
| Brand | Lewmar |
| MPN | 29925001BK |
| UPC | 743683203749 |
| Sheave Diameter | 50 mm |
| Type | Single sheave |
| Safe Working Load | 990 lb |
| Line Range | 1/4 in - 3/8 in (6mm-10mm) |
| Shackle Post Pin Diameter | 3/32 in |
| Mount Type | Swivel Shackle |
| Bearing Type | Free-Spin plain bearing (non-ball-bearing) |
| Materials | Stainless steel shackle post/framework, glass-fiber-reinforced cheeks |
| Weight | ~2.34-2.5 oz (source discrepancy) |
What's Included
- Lewmar 50mm Synchro Single Block (sold individually, no additional accessories listed)
Shipping & Returns
Fast, free shipping from our US warehouse.
Returns accepted per our store return policy.
Specifications
| MPN | 29925001BK |
|---|---|
| Brand | Lewmar |
More Tools & Workshop
Shop all →
Forespar Performance Products · 107915Forespar MF 844 Vented Loop 903016 1 in Barb Marelon$43.99Only 4 left

Bluewater · 110992Bluewater Dual 4 Gang Busbar 313856-B-023 250 Amp$43.99In stock

Bluewater · 110999Bluewater 12 Position Beaker Block w/Cover 3200-2001-012 100A 48V DC Marine$53.99In stock

Bluewater · 111028Bluewater Off/1/2/Both Battery Switch 9800-007-11 Surface Mount Red$53.99Only 3 left