Robust API Crown Bocks

Designed to withstand highest loads, a Highdrilling crown block assembly is the true crown on every rig. Single-piece sheaves with hardened sheave grooves, heavy-duty bearings, and mounted on a rugged steel alloy platform provide the stability needed for tough drilling operations.


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Main Specifications

Standards API Spec 4F, API Spec 8C
Maximum hook loads 900 kN-6,750 kN ( lbs-1,488,400 lbs)
Number of sheaves 5-9

Crown Block Quality That Shows

Highdrilling crown blocks are strictly manufactured to the latest edition of API 4F and API 8C and authorized to carry the API monogram. We use them on all of our land drilling rigs, mobile rigs, and self-propelled workover rigs due to their reliability.

Sheaves That Live Up to Their Task

In addition to the main sheaves and a sand-line sheave, a Highdrilling crown block assembly is are also equipped with a large fast line sheave and two sets of smaller sheaves for the auxiliary winches.

Sheaves are machined from an integral steel alloy body and subsequent heat treatment to eliminate rim cracks and enhance stability. Sheave grooves further undergo medium frequency hardening which significantly reduces wear from the wireline. Individually mounted on heavy-duty tapered roller bearings, each sheave rotates nearly frictionless.

Highdrilling Crown Block Design Features

  • Manufactured to API Spec 4F and API Spec 8C
  • Each crown block sheave is machined from a integral steel alloy cast for enhanced strength.
  • Induction hardened sheave grooves provide superior wear resistance
  • Individual lubrication passage to each bearing for easy maintenance
  • Sheaves and bearings interchangeable with those of Highdrilling traveling blocks.
  • Rugged steel alloy crown platform equipped with stable safety handrails
  • Crown bumper to protect both the crown block and traveling block.

Crown Block Specifications

Model Max. hook load kN (lbs) Wireline Ø mm (in) Sheave OD mm (in) Number of sheaves Dimensions (LxWxH) mm
CB30 300 (66000) 24 (1 5/16) 475 (18 3/4) 4 738×472 ×575
CB50 500 (110000) 24 (1 5/16) 610 (24) 5 860×670 ×588
CB90 900 (200000) 26 (1) 660 (26) 5 1208×1092 ×1207
CB135 1350 (300000) 29 (1 1/8) 1005 (40) 5 2320×1436 ×1781
CB170 1700 (374000) 29 (1 1/8) 1005 (40) 6 2668×2460 ×1855
CB225 22250 (500000) 32 (1 1/4) 1120 (44) 6 2668×2709 ×2469
CB315 3150 (700000) 35 (1 3/8) 1270 (50) 7 3112×2783 ×2800
CB450 4500 (1000000) 38 (1 1/2) 1524 (60) 7 3407×2722 ×2856