Low mounting points for maximum strength
Sheave Ø - 1 9/16 in.
Max. Rope Ø - 5/16 in.
Max. Wire Ø - in.
Pin Ø - in.
Max. Working Load - 385 lb
B. L. - 1102 lb
Weight - 1.3 oz
Product Information
Automatic and manual ratchet options
Now you can enjoy the flexibility of setting up your fitout exactly to suit yourself. Ronstan is the only company that offers a 40mm ratchet block with both auto and manual engagement models*
With automatic models, the ratchet mechanism engages when load is applied, but switches off when it's released. This lets the sheet run out smoothly and freely-great for rapid easing of the sheet and for gybing asymmetric spinnakers.
Manual modes allow the ratchet mechanism to be switched on or off as required. This is the preferred mainsheet set-up for may top sailors.

Selected Series 40 models.
Awesome ratchet block holding power
Quite simply, Ronstan Ratchet Orbit Blocks™ have the highest holding power available. The sophisticated NC-machined sheave features Generation 2 of our patented sheave cross-hole geometry. The Series 40 delivers up to 14:1 holding over, almost double that of our nearest competitor.
The unique sheave design has 8 gripping faces which directly resist loaded line movement. Traditional designs have an angled resistance to line movement. Our Generation 2 design has straight resistance faces which both distribute the load and minimize rope wear. These faces are offset from the radial line, to draw the rope down into the gripping area when under load.
Simple and secure attachment
The Dyneema® Link is easily fitted and is retained securely by a molded retainer clip. The flexible link can be left with one end attached to the block when fitting - no more lost shackle pins.
The system is compatible with Dyneema®/Spectra® strops, webbing and carbon connection points - much more so than steel loop tops or shackles.
Smooth easing of sheets
With auto models the sheet runs out smoothly and freely as soon as the ratchet mechanism disengages. When engaged, and with manual models, the sheave cross - hole geometry eliminates the 'shuddering' ease-out that you can expect from traditional v-groove ratchet blocks.
Low profile stand-up kit allows 0° or 90° alignment
Stand-up kits feature a clatter-free rubber boot. You can attach the Dyneema® link so that the block is aligned with the stand-up base or across it. It's a neat low-profile solution which allows full articulation.
Smooth Easing of sheets
With auto models the sheet rounds out smoothly and freely as soon as the ratchet mechanism disengages. When engaged, and with manual models, the sheave cross-hole geometry eliminates the 'shuddering' ease-out that you can expect from traditional v-groove ratchet blocks.
Applications

Dinghy mainsheet systems

Mainsheet fine tune systems on sportsboats & small keel boats

Mainsheet systems on sportsboats using RF7 mainsheet swivel cleat unit

Spinnaker and job sheets on dinghies - especially modern asymmetric classes

Control line applications on larger yachts
Materials

Sheave: Hard anodized Aluminum

Ball Bearings: High compression strength carbon black Acetal

Frame/Cheeks: Toughened, glass fiber reinforced Nylon

Rope Link: UV stabilized, multi-strand impregnated SK75 Dyneema®