Tight seal, easy retraction

An advanced seal technology for hydraulic bolt tensioners recently developed by UK-based Boltight Ltd. takes advantage of the latest composite materials to eliminate oil leakage while allowing the tensioning piston to be retracted more easily after use. The new seals are a two-piece self-energizing design with an “O” ring made from a self-lubricating and durable material. The seals simply click into position and require no adjustment, and they can be manufactured to suit any piston size.

All Boltight tools incorporate the new seals. Using the tools, bolt tensioning can be carried out in much less time while still ensuring an accurate and uniform bolt load across a joint face. This is critical, the company says, as inaccurate bolt tightening could lead to leaks and even failure of the bolts through fatigue. (

SHARE this article