Hilti says its X-BT system is an innovative way of fastening to pre-painted steel without damaging the protective coating.

The X-BT fastening system is designed to work on construction steels as thin as 8 mm (5/16 inch) in corrosive environments such as those found offshore and in the shipbuilding and petrochemical industries.
X-BT studs do away with rework to pre-painted steel base materials, boosting productivity and reducing costs in comparison with conventional techniques, says Hyunsoo Kim, product manager at Hilti Regional office in Dubai.
Based on Hilti's DX direct fastening principle, X-BT is made of A4/AISI 316 high-grade stainless steel and has a durable sealing washer. The special blunt tip is designed to avoid through-penetration of the base material. During the driving process, the washer forms a permanent seal around the entry point.
X-BT is an alternative to such methods as stud welding, through-bolting and clamping. It also serves as an alternative to the standard Hilti DX technique where through-penetration is not desired.
'Stud welding generally involves additional operations such as grinding off the surface coating and then repair of the damaged coating,' Kim points out. 'With X-BT, the stud with sealing washer is cleanly set in a small pre-drilled hole. Similarly, through-bolting results in an unprotected hole which should be coated. These additional steps are eliminated with X-BT as the user fastens directly to the pre-painted surface.
'Clamping, a common fastening method, is limited in use by the shape of the base material and clamps have a tendency to become loose under vibration. With X-BT, you can fasten to most steel shapes including tubulars, channel sections, wide flanges and angles.'
X-BT supports a wide range of applications such as fastening grating, cable connectors (T-bars), lighting, cable trays, junction boxes, instrumentation and pipe hangers, among others.
The X-BT system is described as being easy and safe. A single user can set more than 100 studs in an hour with no rework involved, says Hilti.
'The installation method is as easy as drill and drive,' explains Kim. 'Drill a 6 mm deep hole in the base material surface using a X-BT 4000-A cordless drill and TX-BT step drill bit, then simply drive the X-BT stud with a DX 351 BT powder-actuated fastening tool.
'Driving the blunt tip of the X-BT stud into the pre-drilled hole creates a true weld by friction, providing pullout values comparable with those found in stud welding. The combination of tools makes the system fully portable.'