1 Reference information1.4. Screw joints3HAC023297-001 Revision: A141.4. Screw jointsGeneralThis section details how to tighten the various types of screw joints on the robot and thecontroller.The instructions and torque values are valid for screw joints comprised of metallic materialsand do not apply to soft or brittle materials.UNBRAKO screwsUNBRAKO is a special type of screw recommended by ABB for certain screw joints. Itfeatures special surface treatment (Gleitmo as described below), and is extremely resistant tofatigue.Whenever used, this is specified in the instructions, and in such cases, no other type ofreplacement screw is allowed! Using other types of screws will void any warranty and maypotentially cause serious damage or injury!Gleitmo treated screwsGleitmo is a special surface treatment to reduce the friction when tightening the screw joint.Screws treated with Gleitmo may be reused 3-4 times before the coating disappears. Afterthis the screw must be discarded and replaced with a new one.When handling screws treated with Gleitmo, protective gloves of nitrile rubber type shouldbe used.Screws lubricated in other waysScrews lubricated with Molycote 1000 should only be used when specified in the repair,maintenance or installation procedure descriptions.In such cases, proceed as follows:1. Apply lubricant to the screw thread.2. Apply lubricant between the plain washer and screw head.3. Tighten to the torque specified in section Tightening torque below. Screw dimensionsof M8 or larger must be tightened with a torque wrench. Screw dimensions of M6 orsmaller may be tightened without a torque wrench if this is done by trained andqualified personnel.Tightening torqueBefore tightening any screw, note the following:• Determine whether a standard tightening torque or special torque is to be applied. Thestandard torques are specified in the tables below. Any special torques are specified inthe Repair, Maintenance or Installation procedure description. Any special torquespecified overrides the standard value.• Use the correct tightening torque for each type of screw joint.Lubricant Art. no.Molycote 1000 (molybdenum disulphide grease) 1171 2016-618