Eastman - Slogging spanners(Ring End)-CRV_E-2082_85 mm CRV Ring End Slogging Spanner is a durable and corrosion-resistant tool. This 85 mm CRV Ring End Slogging Spanner is a quality product made up of chrome vanadium steel or carbon steel. The CRV Ring End Slogging Spanner has a ring-shaped jaw with an internal hook that provides grip over a nut or bolt. Slogging Spanners are effective for releasing stuck nuts by passing a high level of force and vibration to the nut when struck with a hammer. This Spanner is widely used with large locks like a nut or a bolt designed to be used in heavy machinery.hich are stuck, as they pass high levels of force and vibration through to the nut or bolt when hit with a hammer. Add that extra grip to the objects of choice, or loosen up for an easy removal with these durable and reliable spanners. A perfect addition to your mechanics kit, these must-have spanners from top brands are an absolute delight. The application of the slogging ring spanner can be found in mining, piping, ship maintenance, etc.