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

Product Description

The McKissick M-491G Series Derrick Hoist Block is a heavy-duty block engineered for demanding derrick hoisting and oilfield lifting applications where high load capacity and long service life are critical requirements. Rated for a 15-ton working load, this block accommodates up to 7/8 in wire rope and features a 16 in outside diameter roll forged sheave fitted with sealed tapered roller bearings, delivering superior load-carrying capacity, reduced friction, and extended bearing life compared to bushing-type designs. The sealed bearing configuration protects internal components from contamination in harsh field environments, reducing maintenance requirements and downtime.

The roll forged sheave construction provides enhanced strength and fatigue resistance relative to cast alternatives, making it well suited for high-cycle derrick operations where rope and sheave wear are primary concerns. The M-491G Series is designed to perform reliably in oilfield, construction, and heavy industrial derrick systems where consistent hoisting performance under sustained loads is essential. The sheave groove profile is matched to the specified wire rope diameter to promote even load distribution and minimize rope distortion over extended service.

McKissick's M-491G Series represents a premium tier within their derrick block product family, combining roll forged sheave technology with sealed tapered roller bearings to meet the demands of continuous-duty hoisting in challenging field conditions. These blocks are commonly specified by drilling contractors, derrick operators, and rigging engineers who require a dependable, low-maintenance hoist block for critical lifting operations.

Material:

Steel shell and frame construction (confirm specific alloy and finish with manufacturer documentation) Roll forged sheave Sealed tapered roller bearings

Compatible With:

7/8 in wire rope Derrick hoisting systems

Uses:

Derrick hoisting and lifting operations Oilfield drilling and workover rig applications Heavy construction crane and derrick systems High-cycle industrial hoisting

Key Features:

15 Ton capacity 7/8 in maximum cable diameter 16 in sheave outside diameter Roll forged sheave construction Sealed tapered roller bearings M-491G Series construction

Note:

Confirm material finish, certifications, working load limit documentation, and sheave material specifications directly with McKissick or an authorized distributor before specifying for a particular application.