Choosing the Correct Hook Size

When attaching ratchet straps to securing / lashing points or the vehicle chassis, it’s important that the hooks fit correctly into the base radius.

The hook must fit the point it’s being secured to without applying force while still allowing the hook to rotate.

Using a hook on an oversized point can cause premature failure at significantly less loading than the hook is originally rated for.

A hook failure comprises the safety of both the lashing and the load it’s securing.

This information applies to direct lashing too, i.e. when the hook is directly connected to the load (for example plant and construction equipment).

How do I check?

• In the product listing for our endfittings there will be a line drawing or text in the description field confirming the maximum diameter the hooks can be placed over.
  
  

• Measure the diameter of the lashing point accurately using suitable equipment.

• Reference the diameter of the lashing point to a suitable endfitting, if you need further support please Contact Us | Tensys Direct and we’d be happy to help you make the right choice.

Buy Ratchet Straps

These are some of our most popular hooks:

• 50mm · 5000daN · Claw Hook (206728) - Tensys Direct Max Diameter 18mm
  
  
• 50mm · 3000daN · Claw Hook (206724) - Tensys Direct Max Diameter 17mm
  
  
• 50mm · 3000daN · Claw Hook - Cranked (206725) - Tensys Direct Max Diameter 16mm
  
  
• 50mm · 2000daN · Claw Hook (206722) - Tensys Direct Max Diameter 15mm
  
  
• 50mm · 5000daN · Claw Hook with Safety Catch for 15mm Bar (206730) - Tensys Direct Max Diameter 16mm
  
  
• 50mm · 5000daN · Claw Hook - Single (206729) - Tensys Direct Max Diameter 20mm
  
  
• 50mm · 5000daN · Claw Hook with Safety Catch for 30mm Bar (206731) - Tensys Direct Max Diameter 32mm
  
  
• 50mm · 3000daN · Forged Hook (with wire safety catch) (206762) - Tensys Direct Max Diameter 13mm
  
  
• 50mm · 5000daN · Twisted Snap Hook (206801) - Tensys Direct Max Diameter 22mm
  
  
• 50mm · 5000daN · Flat Snap Hook (206765) - Tensys Direct Max Diameter 22mm

Safety Risks

Hooks placed on an oversized diameter can cause premature failure like the image below. Even the standard tension force of a ratchet of between 350-500daN (kg) can be enough to break a 5.0 Tonne hook as the force acts outwards rather than in parallel with the hook.

Even if the hook doesn’t fracture it may be deformed or partially fractured so it will prematurely fail on the next use. Always check your lashings, hooks, and ratchets prior to every use, for cracks, deformation, nicks, cuts and tears.

Ratchet Straps from Tensys Direct