anchor bolts and blocks

Leaf chain anchor bolts & blocks

FB Leaf Chain has developed a standard range of chain anchor bolts and blocks available on quick turnaround whether you’re making a prototype, upgrading or repairing an old piece of equipment. These anchor parts have been designed to the latest leaf chain standard ISO4347:2015. This will mean a chain that adheres to this standard it will always fit. Please follow the links below to the sizing chart and anchor details.

Have you already selected the chain you want to use?

If you are repairing a piece of equipment you do not need to consider this step, all you need to do is identify your chain and then move onto the next step. If you are designing a new chain system, we would recommend applying a minimum of a 5:1 safety factor on your working load to discover your required UTS. Please also consider your equipment’s lifecycle and what you would expect a daily or weekly lifting cycle to be.

Bolt, block or both?

Our standard threaded anchor range offers a long and short threaded version to suit your application. When you select these components for your design here are a few things to consider:

How much adjustment do you need? – As a maximum you need 3% of the total length of chain as adjustment shared across both of your anchor parts. As a minimum you could use 3% of the total section of chain that wraps around the pulley or pulleys you have in your leaf chain system. This is generally the part of the chain that wears over time as this is the only section of chain that articulates.

How much space do you have around the anchors? – If you have little or no room at one end then you can use a long anchor at one end and a short anchor or even a block at the other. You will always need to add a function for adjusting the chain as it wears over time.  For more information on please see the Knowledge Hub article that covers chain wear: /knowledge-hub/chain-wear-gauge-faq-fb-chain-professional

Parts are as strong as the chain

All parts have been designed so that they are as strong or even stronger than the UTS of the chain that they are to be used with. Both tensile and shear strength of the anchor head have been calculated to ensure that these parts adhere to ISO 4347:2015. These parts should never see anything close to this load due to the safety factor applied to your working load.

Thread size has been selected based on the chain that the anchor is for, ensuring that the UTS of the thread is the same as or greater than the chain it is to be used with. For example, our BL0866 chain has a UTS of 309kN and the thread we have selected for the standard part is M30 x 3.5 which has a UTS of 441.20kN. We can supply all anchor parts with Nuts that you wish to use. Please see below link to a Knowledge Hub article that discusses your choices when selecting locking nuts: /knowledge-hub/what-type-of-nuts-should-i-specify-on-leaf-chain-anchor-bolts

Fixing your block

There are various ways to fix your anchor part to your applications mast. In the picture below you can see six different styles of fixing.

Our standard range covers three of these executions as these tend to be the most popular. If you require any of the other executions, please contact us directly to discuss your requirements.

Additional coating

All component anchor bolts and blocks are manufactured in a natural and oiled condition. This may be fine for your application as it may not be exposed to any adverse conditions. If your application is to be used outside or in harsh conditions, we can supply any number of these standard parts in our SuperShield coating. This Zinc Flake finish will provide surface rust prevention up to 500 hours to ASTM B117-19.

What to do if you can’t use one of our standard parts

We can manufacture all sorts of wonderful high quality chain anchors. If your application requires something different or our standard range is unsuitable for your application, then please contact us. We can discuss your application and design something bespoke to suit your needs.

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