Harken Ball Bearing Blocks

Harken is universally acknowledged as the global leader in the development of performance blocks featuring ball bearings manufactured in 316 Stainless Steel, UV-stabilised Delrin Acetal Resin and the hardest, smoothest of them all:  Zirconium/Ceramic, seven and a half times stronger in compression than stainless bearings.

Harken Ball Bearing Blocks: Material Facts and Features

Harken Stainless Steel Ball Bearings

• 316 Stainless Steel: high corrosion resistance in freshwater and saltwater but cannot be hardened
• 17-4 PH Stainless Steel: more corrosion-resistant than 316 stainless steels, hardened to extremely high strength, excellent for, e.g. gears and gearing
• XM-19 Stainless Steel: high alloy content, high mechanical strength and superior corrosion resistance, excellent for, e.g. rods and pins in Harken cylinders

Harken Delrin® Acetal Resin Ball Bearings

• Black, UV-stabilised, durable
• Excellent for ball bearings, sheaves, and side plates.

Harken Torlon® Thermoplastic Ball Bearings

• High strength, crush, shock load and impact-resistant
• Hard-working for extended heavy duty,
• Greenish-brown colour
• Excellent for Harken extreme loading blocks and ancillary hardware

Harken Zirconium Ball Bearings, also commonly known as Ceramic

• Zircon bearings are the ultimate in hardness and smoothness
• Zircon bearings are approximately seven and a half times stronger in compression than stainless bearings, size for size.
• Ceramic/Zircon bearings are the ultimate in low friction efficiency, absorbing far less energy before they begin to roll.

Harken Ball Bearings: from left to right in the photo below = Delrin, Torlon and Zirconium

Harken UV-Stabilising

• Sunlight causes composites to become brittle, lose strength and discolour by breaking their chemical bonds
• Harken composite side plates, sheaves and bearings undergo a Carbon Black UV stabilising process for extended working life

Harken Hard-Coat Anodising

• Hard-Coat aluminium anodising is an electrochemical process that results in a corrosion-resistant finish with a hardness second only to diamonds
• The Harken Hard-Coating process is double the thickness compared with black anodising, providing extra protection against surface damage and corrosion

Harken Hard-Lube Anodising

• Hard Lube-anodised aluminium has the same corrosion resistance as Hard-Coating with a PTFE coating for an even smoother, reduced-friction finish

Harken Carbon Black Process

• Carbon black is a UV-stabilising colour additive applied to Delrin ball bearings, sheaves, and side plates to enhance resistance to the sun’s damaging rays

Harken Information on Block Loading Relative to the Angle of Deflection

The loading on a block is a combination of the load on the line plus a deflection loading factor, which is determined by the turning angle.  

For example, a 180-degree turn will result in twice the load on the line being applied to the block.

While a 30 degree deflection will only transfer 52 percent of the load on the line to the block.