The Common Troubleshooting of Wire Hook Fastener

Although wire hook fastener splices are very reliable, there are times when a splice may not be performing to the user’s expectations. Following are some potential problems they may be facing:

Hooks Open Up and Release From Belt End

Possible Causes:

• Wrong size hook may have been selected.
• Tension may be too high for the strength of the hook.
• Hooks may be under-compressed.
• Belt may not be cut square.
• Belt may be mistracking.

Hooks Pull Through Belt End Without Opening Up

Possible Causes:

• Hooks may not be reaching back far enough into the belt.
• Wrong belt may have been selected.
• Belt end may not be cut square.
• Wrong size hook may have been selected.
• Hook may be too large for the minimum pulley.

Belt Fractures Directly Behind Fasteners

Possible Causes:

• Hook may be too large for the minimum pulley.
• Incorrect belt may have been selected.
• Wrong size hook may have been selected.

Step in the Lacing

Possible Causes:

• Incorrect installation procedures may have been used.
• Belt end may not be cut square.

Hooks Rust or Corrode

Possible Cause:

• Wrong hook material may have been selected.

Connecting Pin Fractures Prematurely

Possible Causes:

• Connecting pin may be too rigid for the application.
• Belt may be mistracking.
• Wrong connecting pin may have been selected.

Premature Connecting Pin Wear

Possible Causes:

• Wrong connecting pin may have been used. Consider a connecting pin with more resistance to abrasion.

Connecting Pin Difficult To Insert Into Splice

Possible Causes:

• Wrong connecting pin may have been selected.
• Pin may not be rigid enough. Consider using a solid core pin or a pin with a leader assembly.
• Belt Wave may be occurring. Consider switching wire hook.
• Hooks may be improperly installed.

Connecting Pin Migrates Out Of Splice:

Possible Causes:

• Belt end may not be cut square.
• Wrong pin material may have been selected.
• Smooth exterior of the pin might be allowing the pin to migrate out of the splice. Consider using notched steel or stainless pins.
• Pin may not be secure in the splice. Consider 'J End' pins.

Hook Legs Fracture Prematurely

Possible Causes:

• Hook size may exceed the recommended minimum pulley diameter.
• Hooks may have been over-compressed.
• Hooks may have been under-compressed.

A Flat Spot Is Worn On The Hook Knuckle

Possible Causes:

• Metal chosen for hook is not abrasion resistant enough for the application. Select a material that is more abrasion resistant (i.e. high tensile).
• Hooks may be under-compressed.
• Hooks may be over-compressed and have caused the knuckles to back out of the belt.

Premature Loop Wear

Possible Causes:

• Wrong connecting pin may have been selected.
• Connecting pin may need replacement.
• Metal chosen may not be abrasion resistant enough for the application. Select a material that is more abrasion resistant (i.e. high tensile).
• Hooks may be over-compressed, causing a "light bulb" loop shape.

Hook Loops Lean Together In Pairs

Possible Causes:

• Hooks may be under-compressed.
• May be using carded hooks. Consider using hooks, where each individual hook is welded to a common bar, keeping the hook legs parallel.

Hooks Twist

Possible Causes:

• Hooks may be over-compressed.
• Hook points may be too long for the belt thickness.

Splice Triggers Magnetic Detector

Possible Causes:

• Hook selected may be magnetic. Consider switching to a material without magnetic properties: Bronze, Hastelloy, or Inconel. 316 Stainless Steel is only slightly magnetic and can often be used.

Splice Triggers Metal Detector

Possible Cause:

• All hooks will trigger metal detectors. Consider switching to a non-metallic fastener such as Alligator Spiral or Alligator Plastic Rivet.
• Hook Points Twist (lay over) Instead of Properly

Penetrating Belt

Possible Causes:

• Belt may be too hard for the hook points to properly penetrate. Heat hook points or belt prior to installation.
• Hook points may be too long for the belt thickness.

End Hooks Pull Out Of Splice

Possible Causes:

• Lacing may be too close to the edges. Leave 1/4 -1/2" unlaced on both sides of the belt.
• Hooks may be under-compressed.
• Tension load may be too high for the strength of the hook. Consider a larger size hook, a hook made from a larger diameter wire, and/or a hook made from high tensile wire.
• Pin may be too short, allowing the splice to snag on obstructions.

Belt Wave

Possible Causes:

• Hooks may be over-compressed.
• Belt displacement may have occurred during the installation of the splice. Consider switching fasteners. The welded bar keeps the splice flat and eliminates the belt wave.