Series 5 Single Fixed Eye Block - 54mm Plain Bearing Blocks Barton plain bearing blocks have a precision moulded acetal sheave running on a large diameter brass bearing, ensuring free running under the highest of loads. Specifications Sheave size: 54mm x 17mm Max rope diameter: 12mm Safe working load: 750kg / 1650lbs Breaking load: 1500kg / 3300lbs Length: 107mm Weight: 154g This range of high load cruiser bocks are of rugged construction, featuring high quality injection moulded side plates with all load-carrying components from 316 grade stainless steel. Side plates are through-bolted and riveted for added strength and security. This good looking and versatile range is designed for use on large cruising and racing yachts. All are designed for ease of use with our ball-bearing mainsheet traveller systems.