Grip-Bar® Anchor Systems

The Grip Bar® Anchor System has been developed specifically for civil engineering and geotechnical applications where high load capacity, durability and corrosion resistance are required.

Load Nut - GBLN

Lock - GBLN

Coupler - GBCR

Plate Washer

Manufacturing Process

High strength Grip Bar® is manufactured from cold drawn stainless steel bar feedstock. The cold working process provides elevated strength while retaining the inherent ductility of stainless steel.

Grip Bar® is supplied as fully threaded bars in standard 6-metre lengths. Bespoke end threading and non standard lengths can be supplied to special order.

All Grip Bar® products utilise a thread rolling process. This cold forging method forms a coarse thread without removing material from the bar. The resulting grain flow significantly improves thread strength.

Corrosive Considerations

The corrosion performance of Grip Bar® anchor systems is governed primarily by the selection of an appropriate stainless steel grade for the intended service environment.

Grade 304 (1.4301) is suitable for dry internal or mildly corrosive external environments where chloride exposure is low.

Grade 316 (1.4401 / 1.4436) is recommended for external, highway and coastal applications where chlorides may be present, offering improved resistance to pitting and crevice corrosion.

Duplex stainless steel grade 1.4462 may be specified for aggressive environments with high chloride concentrations or where increased resistance to stress corrosion cracking is required.

Bond Performance

The Grip Bar® thread profile has been developed through extensive testing undertaken by Stainless UK and the University of Sheffield.

Bond tests conducted in accordance with BS 8110 Type 2 reinforcing bar requirements demonstrated bond strength well in excess of code limits.

Additional testing in rock bolting applications with varying free and bonded lengths has shown Grip Bar® to significantly outperform reinforcement bar comparators.

Site Performance

Grip Bar® uses a cold rolled coarse pitch thread that enhances strength and provides a robust, user friendly thread well suited to site handling.

The coarse pitch reduces susceptibility to galling compared with traditional metric threads and allows faster assembly.

The large flank angle supports the thread crown, enabling the bar to withstand significant site abuse while remaining fully serviceable.

Fittings

Grip Bar® fittings are designed to provide an anchorage capacity equal to the theoretical minimum strength of the Grip Bar.

Fittings are kept as compact as possible to minimise drill hole diameters, reducing drilling time and installation costs.

Use Loctite® 268 with Activator 7649 to prevent nuts loosening under vibration.

Comparison with Threaded Reinforcement Bar

Conventional rock anchoring systems using reinforcement bar with cut threads suffer strength reduction due to loss of cross section.

Grip Bar® is manufactured from higher strength material and benefits from work hardening through thread rolling, giving a minimum proof stress of 650 N/mm².

University of Sheffield testing has shown Grip Bar® bond strength up to first slip to be at least 2.8 times that of equivalent reinforcement bar.

Grip Bar® is fully threaded along its length and can be cut to size on site without compromising thread integrity, offering greater installation flexibility.