HEICO-TEC EXPANSION BOLT FOR THROUGH-BORE 

• Mechanical expansion bolts made of high-strength steel enables precise, displacement-controlled radial and axial preloading

• Pre-tensioning using proven HEICO-TEC® Tension Nuts

• Designed to user specific requirements

• Operation from two sides

• Selectable dimensions

​

​

DESIGN AND FUNCTION

​

For through-bores in highly dynamic applications, the through-hole expansion bolt is the ideal fastening element. The through-bore expansion bolt is designed with two HEICO-TEC® Tension Nuts, so it can be pre-tensioned radially and axially.

​

Like all expansion bolts, the through-bore expansion bolt features a conical bolt and a slotted conical sleeve. Additionally, it includes two HEICO-TEC® Tension Nuts, each attached at one end of the conical bolt. A spacer sleeve positions the conical sleeve centrally to the joint. The conical sleeve is pre-assembled onto the conical bolt and both are inserted as one unit into the bores. Due to the slotted design of the conical sleeve, it has enough flexibility to be inserted effortlessly, even if the bores are slightly misaligned. The spacer sleeve is then placed into the bore. By tightening the first HEICO-TEC® Tension Nut on the operating side, the through-bore expansion bolt is centered. Then the second HEICO-TEC® Tension Nut can be tightened on from the backside.

​

The expansion of the conical sleeve is adjusted using a feeler gauge. A defined gap is set between the second HEICO-TEC® Tension Nut and the coupling flange, corresponding to the required distance to achieve the desired radial pre-tension. On the operating side, the pressure bolts of the first mounted HEICO-TEC® Tension Nut are fastened. This pulls the conical bolt into the conical sleeve, causing it to expand and thus apply radial pre-tension to the connection. To also apply axial pre-tension to the connection, the pressure bolts of the second HEICO-TEC® Tension Nut on the backside are then fastened.

​

This process allows tensile loads or cyclic bending moments to be transmitted while also creating additional frictional contact in the joint, thereby increasing the transmittable coupling torque. To disassemble the through-bore expansion bolt, the HEICO-TEC® Tension Nut on the operating side is first loosened. The second HEICO-TEC® Tension Nut is then tightened to pull the conical bolt out of the conical sleeve. Thanks to the slots, the conical sleeve contracts, and the through-bore expansion bolt is easily removed from the bore with minimal effort.

​

​

ADVANTAGES

​

• Simple pretensioning using HEICO-TEC® Tension Nuts

• Defined radial preload through strain-controlled tightening

• Axial and radial preload ensure maximum clamping force

• No additional costs for special tools or unnecessary reworking of bores and fitted pins

• Simple assembly and disassembly

• Reusable

Click here for the enquiry form!