McKissick M-491S Derrick Hoist Block - 15 Ton - 7/8 in Wire Rope - 16 in Sheave - Roll Forged

Description du produit

The McKissick M-491S Derrick Hoist Block is a heavy-duty hoisting block engineered specifically for derrick and crane applications where high load capacity, precision bearing performance, and sheave durability are essential. Rated for a 15-ton working load limit and compatible with wire rope cable up to 7/8 inch in diameter, this block is built for sustained use in oilfield, marine, offshore, and heavy construction derrick systems where reliable performance under repeated high-load cycles is required. The M-491S designation reflects McKissick's purpose-built derrick block line, designed to meet the rigorous demands of vertical hoisting in fixed and mobile derrick configurations.

The block features a sealed tapered roller bearing, which provides superior load-carrying capacity, precise sheave alignment, and effective resistance to contamination from dirt, water, and other field debris. Sealed bearings eliminate the need for frequent regreasing in the field, reducing maintenance intervals and extending service life in remote or offshore environments. The 16-inch OD roll forged sheave is a key performance feature — roll forging produces a sheave with enhanced grain structure, greater surface hardness, and improved resistance to wear and groove deformation compared to cast sheaves, making it well suited to high-cycle wire rope hoisting applications.

At 15 tons working load limit with a 16-inch OD roll forged sheave and sealed tapered roller bearing, the M-491S is configured for applications where sheave longevity and bearing reliability directly impact operational uptime. This block is appropriate for use in derrick hoisting systems, crane blocks, and other fixed or mobile lifting configurations requiring a robust, low-maintenance hoisting block. Always confirm wire rope diameter compatibility, attachment hardware ratings, reeving configuration, and full system load ratings before placing the block into service.

Material:

Steel block body Roll forged sheave Sealed tapered roller bearing

Compatible With:

Wire rope cable up to 7/8 in diameter

Uses:

Derrick hoisting systems Crane and hoist block applications Oilfield and offshore lifting operations Heavy construction vertical hoisting Fixed and mobile derrick configurations

Key Features:

15 Ton working load limit 16 in OD roll forged sheave Accepts wire rope up to 7/8 in diameter Sealed tapered roller bearing for high load capacity and contamination resistance Maintenance-reduced sealed bearing design M-491S Derrick series construction