ISC RP057 Large Arborist Rigging Block

Heavy-Duty Arborist Rigging Block for 3/4" Rope — Built for Serious Loads

The ISC RP057 Large Cast Rigging Pulley is engineered for high-load tree rigging operations, offering exceptional strength, durability, and compatibility with 3/4" (19 mm) rope. This block is trusted by professional arborists for lowering heavy limbs and controlling large loads with confidence. It features color-coded side plates and a pulley wheel to aid in quick visual identification of block size in the field.

Designed for both performance and safety, the RP057 has an impressive Working Load Limit (WLL) of 8,800 lbs and a Minimum Breaking Strength (MBS) of 200 kN (44,962 lbf). The pulley accommodates a 19 mm (3/4") working line and a 29 mm (1-1/8") topping strop, aligning with best practices that recommend using a stronger anchor strop than the working line. The fixed bollard dimension makes it easy to comply with this rigging standard.

The body and sheave are made from lightweight, yet tough powder-coated aluminum, making the RP057 both strong and manageable in the field. Weighing just 2.3 kg (5.3 lbs), it's a go-to block for rigging crews who demand strength without bulk.

Specifications:

• Rope Compatibility: 19 mm (3/4") working line, 29 mm (1-1/8") topping strop
• Working Load Limit (WLL): 4000 kg (8,800 lbs)
• Minimum Breaking Strength (MBS): 200 kN (44,962 lbf)
• Construction: Aluminum side plates and pulley wheel
• Finish: Powder-coated with color-coded cheeks and wheel
• Weight: 2.3 kg (5.3 lbs)
• Dimensions: 300 mm (11-7/8") length x 158 mm (6-1/4") width x 108 mm (4-1/4") depth

For arborists tackling large-scale rigging jobs, the ISC RP057 is a powerhouse pulley that brings together smart design, rugged construction, and performance-driven specs—all from a brand arborists trust worldwide.