McKissick M-491G Derrick Hoist Block - 3/4 in - 12 Ton - 14 in - Roll-Forged

Description du produit

The McKissick M-491G Derrick Hoist Block is a heavy-duty single-sheave hoist block engineered for derrick and overhead lifting applications requiring reliable, high-cycle performance in oilfield, construction, and industrial environments. Rated for a 12-ton working load limit, this block is built around a 14-inch outside diameter roll forged sheave supported by a sealed tapered roller bearing, providing high radial and axial load capacity with integrated contamination protection and superior sheave durability for extended service life under demanding field conditions. The M-491G series in this configuration accommodates wire rope cable up to 3/4 inch in diameter.

The roll forged sheave construction delivers superior strength and fatigue resistance compared to cast sheave alternatives, making this configuration of the M-491G well suited for high-cycle derrick hoist operations and applications subject to shock loading or sustained tension in demanding oilfield and construction environments. The sealed tapered roller bearing delivers superior load capacity and precise sheave alignment under combined radial and axial loads, while the integrated seal protects the bearing from contamination by dirt, dust, moisture, and debris, reducing maintenance requirements and extending operational life in harsh field environments where routine servicing may be limited. The 14-inch sheave diameter provides a generous rope bend radius for the 3/4-inch wire rope accommodated by this block, supporting rope longevity during high-cycle hoist operations while offering a more compact overall profile than larger sheave configurations in the same series.

The M-491G designation distinguishes this block from the M-491S variant within the McKissick derrick hoist block line. Both series share the same sealed tapered roller bearing and roll forged sheave construction in higher-capacity configurations, and are purpose-built for derrick hoist applications, with the M-491G and M-491S designed as distinct configurations to meet specific application or dimensional requirements within the derrick hoist block product family. This block is well suited for use in oilfield derrick systems, construction gin poles, and industrial overhead lifting applications requiring a high-performance hoist block with sealed bearing protection, roll forged sheave strength, and a 12-ton working load capacity.

Material:

Steel (body and side plates) Roll forged steel sheave Sealed tapered roller bearing

Compatible With:

Wire rope cable up to 3/4 in diameter

Uses:

Traveling or fixed block in derrick and gin pole rigging systems Overhead lifting in oilfield and construction environments High-cycle hoist operations requiring sealed bearing protection and roll forged sheave durability Industrial overhead load handling

Key Features:

12 Ton working load limit 14 in sheave outside diameter Roll forged sheave for superior strength and fatigue resistance Sealed tapered roller bearing for high load capacity and contamination protection Accommodates wire rope cable up to 3/4 in diameter Generous rope bend radius for improved wire rope longevity in high-cycle hoist service Sealed bearing reduces maintenance requirements in harsh field conditions McKissick M-491G series