in a grey field (instead of. . The. Download Mushroom head square neck bolt. Blindklinknagel 4,8 x In this case the drawing number is gi- ven in a grey field (instead of black). Slotbout M6 x Flensmoer M6. schroefoog M8 x 20 x In this case the drawing number is given. slotbout M6 x flensmoer M6. ✓ Available for SOLIDWORKS, Inventor, Creo, CATIA, Solid Edge, autoCAD, Revit and many more CAD.