Address:Jennmar Industry Park, Tongji Road, Gaoxin District, Jining, Shandong, China
Tel:0537-2480366, 2480336
Fax:0537-2480338
Contact:Li Li
E-mail:liliyf2@163.com
High strength pre-tension bolt Ⅱ 〔Patent pending〕
Structure:
High pre-tension: Pretension is one of the most important factors to control the surrounding strata effectively. Facilitated with specially made torque-tension nut and “sandwich” harden washer system, this bolt can increase pretention by 30%-50% compared with other similar bolts.
High strength: Using grade 500 rebar, this bolt has higher capacity. Specially treated thread reduces the steel working hardening and the thread part has the same strength as the rebar.
Technical Merits：
This bolt has been successfully applied in medium strength surrounding strata conditions of deep cover, high stress, without influence of dynamic stress , without yield pillar trend.
