diff --git a/LuaLibs/WProcessLapJoint.lua b/LuaLibs/WProcessLapJoint.lua
index 4cb147b..f6e9e49 100644
--- a/LuaLibs/WProcessLapJoint.lua
+++ b/LuaLibs/WProcessLapJoint.lua
@@ -692,15 +692,15 @@ local function CalcInterference( nNewProc, vtExtr, ptCentr, dDiam1, dDiam2,
 
    local ptCentrGrid1 = ptCentr + ( vtExtr * 0.01)
    local frOriTool = Frame3d( ptCentrGrid1, vtExtr)
-   local bColl1 = EgtCDeConeSolid( frOriTool, dDiam1/2, dDiam2/2, dTall1, nNewProc, 0, GDB_RT.GLOB)
+   local bColl1 = EgtTestConeSurface( frOriTool, dDiam1/2, dDiam2/2, dTall1, nNewProc, 0, GDB_RT.GLOB)
    if bColl1 then return true end
    local ptCentrGrid2 = ptCentr + ( vtExtr * ( dTall1 + 0.01))
    frOriTool = Frame3d( ptCentrGrid2, vtExtr)
-   local bColl2 = EgtCDeCylSolid( frOriTool, dDiam2/2, (dTall2-dTall1), nNewProc, 0, GDB_RT.GLOB)
+   local bColl2 = EgtTestCylSurface( frOriTool, dDiam2/2, (dTall2-dTall1), nNewProc, 0, GDB_RT.GLOB)
    if bColl2 then return true end
    local ptCentrGrid3 = ptCentr + ( vtExtr * ( dTall2 + 0.01))
    frOriTool = Frame3d( ptCentrGrid3, vtExtr)
-   local bColl3 = EgtCDeCylSolid( frOriTool, dDiam3/2, (dTall3-dTall2), nNewProc, 0, GDB_RT.GLOB)
+   local bColl3 = EgtTestCylSurface( frOriTool, dDiam3/2, (dTall3-dTall2), nNewProc, 0, GDB_RT.GLOB)
    if bColl3 then return true end
    -- restituisco risultato controllo collisioni
    return false