Jennmar offers the industry’s most proven Combination Bolt system in the mining industry. The Combination Bolt is a two-piece bolt.
The upper piece consists of Jennmar’s exclusive J-Bar for better mixing, stronger threads, and greater anchorage capacity. The lower piece is connected by a coupler that has our patented shear pin system.
The Combination Bolt provides ultimate tension in weak strata. The top portion (J-Bar) is encapsulated with resin, while the lower anchor is tensioned to the roof with our bearing plate.
Advantages of Jennmar’s Combination Bolts
- The ultimate tension resin system for all seam heights.
- Proven Shear Pin system with coupler.
- System permits pre-bolting of overcasts for 50% savings.
- With mine roof channel or mats savings can range from 25% to 140%.
- Proven usage in US longwall headgate and tailgate entries as supplemental or primary support.