Ronstan Series 20 Ball Bearing Block
- Brand:
- Ronstan
- Part no:
- RF20100
A small ball-bearing block. Harken rates ball bearings as very low friction with low to medium load capacity, and Seldén says ball-bearing blocks are used where loads are more moderate and dynamic. That is a different job from a halyard turning block, which Ronstan says may stay highly loaded for hours and for which it says a full-contact or plain bearing is often better suited.
Our take
Buy this for dinghy control lines such as the vang, cunningham or traveller, where a light 20 mm ball bearing block with a swivel head does the job. Stainless balls keep friction low, and the nylon cheeks and 316 stainless strap are sound materials. Skip it for halyards or anything loaded hard. It takes 6 mm line at most, has a 3 mm pin, and its working load is only 250 kg.
Where to buy
Specifications
- Sheave diameter
- 20 mm
- Max line diameter
- 6 mm
- Bearing
- ball
- Weight
- 20 g
- Max working load
- 250 kg
- Breaking load
- 550 kg
- Swivel
- swivel
- Manufacturer size
- Series 20