ABB OmniCore IRB 6720 Product Manual

9.4 Screw jointsGeneralThis section describes how to tighten the various types of screw joints on ABBrobots.The instructions and torque values are valid for screw joints comprised of metallicmaterials and do not apply to soft or brittle materials.UNBRAKO screwsUNBRAKO is a special type of screw recommended by ABB for certain screw joints.It features special surface treatment (Gleitmo as described below) and is extremelyresistant to fatigue.Whenever used, this is specified in the instructions, and in such cases, no othertype of replacement screw is allowed. Using other types of screws will void anywarranty and may potentially cause serious damage or injury.Gleitmo treated screwsGleitmo is a special surface treatment to reduce the friction when tightening thescrew joint. It is recommended by ABB for M6-M20 screw joints. Screws treatedwith Gleitmo may be reused 3-4 times before the coating disappears. After this thescrew must be discarded and replaced with a new one.When handling screws treated with Gleitmo, protective gloves of nitrile rubbertype should be used.Generally, screws are lubricated with Gleitmo 603 mixed with Geomet 500 orGeomet 702 in proportion 1:3. Geomet thickness varies according to screwdimensions, refer to the following.Geomet thicknessLubricantDimension3-5 μmGleitmo 603 + Geomet 500M6-M20 (any length exceptM20x60)3-5 μmGleitmo 603 + Geomet 720M6-M20 (any length exceptM20x60)8-12 μmGleitmo 603 + Geomet 500M20x606-10 μmGleitmo 603 + Geomet 720M20x60Stainless steel screwsStainless steel screws should be secured by hand at least 2 turns before using anelectric screwdriver.Screws lubricated in other waysScrews lubricated with Molykote 1000 or Molykote P1900 should only be usedwhen 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.Continues on next page624 Product manual - IRB 67203HAC085697-001 Revision: C© Copyright 2023 ABB. All rights reserved.9 Reference information9.4 Screw joints