McKissick M-491S Series Derrick Hoist Block - 12 Ton - 3/4 in Wire Rope - 14 in Sheave - Roll Forged

Product Description

The McKissick M-491S Series Derrick Hoist Block is a heavy-duty lifting block engineered for derrick and oilfield hoisting applications where high capacity, durability, and reliable bearing performance are critical. McKissick has long been a trusted name in the rigging and lifting industry, and the M-491S Series reflects that heritage with a robust construction intended for the demanding conditions found in drilling, construction, and heavy industrial derrick operations.

This block is rated for a 12 ton capacity and accommodates a maximum cable diameter of 3/4 in. The 14 in sheave outside diameter is sized to promote favorable wire rope bending ratios, helping to extend cable service life under the high-cycle, high-load conditions typical of derrick hoist use. The roll forged sheave construction provides superior strength and resistance to deformation compared to cast alternatives, making it well suited for applications where shock loading or heavy repetitive lifts are a regular occurrence.

The sealed tapered roller bearing design is a defining feature of this block, providing efficient load transfer, reduced friction, and protection against contamination from dust, moisture, and other environmental factors common on derrick and oilfield job sites. Sealed bearings in this application reduce maintenance requirements and contribute to consistent performance over extended service intervals. The M-491S Series is appropriate for use in derrick hoisting, heavy construction lifting, and other applications requiring a reliable, bearing-equipped wire rope block at the 12 ton capacity level.

Material:

Roll forged sheave Consult McKissick documentation for confirmed housing and frame material specifications

Compatible With:

Derrick and oilfield hoist systems 3/4 in maximum wire rope cable Standard derrick block hook or bail suspension hardware compatible with this block series

Uses:

Derrick hoisting and load handling Oilfield and drilling rig lifting operations Heavy construction crane and derrick applications High-cycle industrial hoisting where bearing performance is critical

Key Features:

M-491S Series derrick hoist block 12 Ton rated capacity 3/4 in maximum cable diameter 14 in sheave outside diameter Roll forged sheave construction Sealed tapered roller bearing Designed for derrick and heavy industrial hoisting applications

Note:

Full dimensional specifications, groove profile details, and additional configuration options should be confirmed against the official McKissick M-491S Series catalog or product documentation. Certifications and standards compliance should not be assumed without verification from McKissick or an authorized distributor.