diff --git a/src/Mod/Fem/femsolver/calculix/writer.py b/src/Mod/Fem/femsolver/calculix/writer.py
index 9fc5d52c59..86e0059d44 100644
--- a/src/Mod/Fem/femsolver/calculix/writer.py
+++ b/src/Mod/Fem/femsolver/calculix/writer.py
@@ -591,22 +591,20 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
         f.write("\n***********************************************************\n")
         f.write("** Surfaces for contact constraint\n")
         f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-        obj = 0
         for femobj in self.contact_objects:
             # femobj --> dict, FreeCAD document object is femobj["Object"]
             contact_obj = femobj["Object"]
             f.write("** " + contact_obj.Label + "\n")
             cnt = 0
-            obj = obj + 1
             for o, elem_tup in contact_obj.References:
                 for elem in elem_tup:
                     ref_shape = o.Shape.getElement(elem)
                     cnt = cnt + 1
                     if ref_shape.ShapeType == "Face":
                         if cnt == 1:
-                            name = "DEP" + str(obj)
+                            name = "DEP" + contact_obj.Name
                         else:
-                            name = "IND" + str(obj)
+                            name = "IND" + contact_obj.Name
                         f.write("*SURFACE, NAME=" + name + "\n")
 
                         v = self.mesh_object.FemMesh.getccxVolumesByFace(ref_shape)
@@ -1044,17 +1042,18 @@ class FemInputWriterCcx(writerbase.FemInputWriter):
         f.write("\n***********************************************************\n")
         f.write("** Contact Constraints\n")
         f.write("** written by {} function\n".format(sys._getframe().f_code.co_name))
-        obj = 0
         for femobj in self.contact_objects:
             # femobj --> dict, FreeCAD document object is femobj["Object"]
-            obj = obj + 1
             contact_obj = femobj["Object"]
             f.write("** " + contact_obj.Label + "\n")
-            f.write("*CONTACT PAIR, INTERACTION=INT{},TYPE=SURFACE TO SURFACE\n".format(obj))
-            ind_surf = "IND" + str(obj)
-            dep_surf = "DEP" + str(obj)
+            f.write(
+                "*CONTACT PAIR, INTERACTION=INT{},TYPE=SURFACE TO SURFACE\n"
+                .format(contact_obj.Name)
+            )
+            ind_surf = "IND" + contact_obj.Name
+            dep_surf = "DEP" + contact_obj.Name
             f.write(dep_surf + "," + ind_surf + "\n")
-            f.write("*SURFACE INTERACTION, NAME=INT{}\n".format(obj))
+            f.write("*SURFACE INTERACTION, NAME=INT{}\n".format(contact_obj.Name))
             f.write("*SURFACE BEHAVIOR,PRESSURE-OVERCLOSURE=LINEAR\n")
             slope = contact_obj.Slope
             f.write(str(slope) + " \n")
diff --git a/src/Mod/Fem/femtest/data/ccx/constraint_contact_shell_shell.inp b/src/Mod/Fem/femtest/data/ccx/constraint_contact_shell_shell.inp
index e38fb246ba..a91d07b3c1 100644
--- a/src/Mod/Fem/femtest/data/ccx/constraint_contact_shell_shell.inp
+++ b/src/Mod/Fem/femtest/data/ccx/constraint_contact_shell_shell.inp
@@ -23072,7 +23072,7 @@ Efaces
 ** Surfaces for contact constraint
 ** written by write_surfaces_constraints_contact function
 ** ConstraintContact
-*SURFACE, NAME=DEP1
+*SURFACE, NAME=DEPConstraintContact
 329,S2
 330,S2
 331,S2
@@ -30571,7 +30571,7 @@ Efaces
 7824,S2
 7825,S2
 7826,S2
-*SURFACE, NAME=IND1
+*SURFACE, NAME=INDConstraintContact
 7827,S2
 7828,S2
 7829,S2
@@ -38371,9 +38371,9 @@ Efaces
 ** Contact Constraints
 ** written by write_constraints_contact function
 ** ConstraintContact
-*CONTACT PAIR, INTERACTION=INT1,TYPE=SURFACE TO SURFACE
-DEP1,IND1
-*SURFACE INTERACTION, NAME=INT1
+*CONTACT PAIR, INTERACTION=INTConstraintContact,TYPE=SURFACE TO SURFACE
+DEPConstraintContact,INDConstraintContact
+*SURFACE INTERACTION, NAME=INTConstraintContact
 *SURFACE BEHAVIOR,PRESSURE-OVERCLOSURE=LINEAR
 1000000.0 
 
diff --git a/src/Mod/Fem/femtest/data/ccx/constraint_contact_solid_solid.inp b/src/Mod/Fem/femtest/data/ccx/constraint_contact_solid_solid.inp
index 62ed85cdbc..618d9cbfb1 100644
--- a/src/Mod/Fem/femtest/data/ccx/constraint_contact_solid_solid.inp
+++ b/src/Mod/Fem/femtest/data/ccx/constraint_contact_solid_solid.inp
@@ -4433,7 +4433,7 @@ Evolumes
 ** Surfaces for contact constraint
 ** written by write_surfaces_constraints_contact function
 ** ConstraintContact
-*SURFACE, NAME=DEP1
+*SURFACE, NAME=DEPConstraintContact
 1344,S4
 1655,S1
 1703,S3
@@ -4892,7 +4892,7 @@ Evolumes
 2594,S3
 2595,S2
 2596,S3
-*SURFACE, NAME=IND1
+*SURFACE, NAME=INDConstraintContact
 1283,S2
 1286,S1
 1289,S1
@@ -5057,9 +5057,9 @@ Evolumes
 ** Contact Constraints
 ** written by write_constraints_contact function
 ** ConstraintContact
-*CONTACT PAIR, INTERACTION=INT1,TYPE=SURFACE TO SURFACE
-DEP1,IND1
-*SURFACE INTERACTION, NAME=INT1
+*CONTACT PAIR, INTERACTION=INTConstraintContact,TYPE=SURFACE TO SURFACE
+DEPConstraintContact,INDConstraintContact
+*SURFACE INTERACTION, NAME=INTConstraintContact
 *SURFACE BEHAVIOR,PRESSURE-OVERCLOSURE=LINEAR
 1000000.0