diff --git a/LuaLibs/ProcessStepJointNotch.lua b/LuaLibs/ProcessStepJointNotch.lua
index dbb586a..a24dec6 100644
--- a/LuaLibs/ProcessStepJointNotch.lua
+++ b/LuaLibs/ProcessStepJointNotch.lua
@@ -288,8 +288,8 @@ local function MachineByMill( Proc, nPhase, nRawId, nPartId, b3Solid, ptC, vtN,
          -- setto a 0 eventuali offset
          EgtSetMachiningParam( MCH_MP.OFFSR, 0)
          -- applico gli allungamenti o accorciamenti considerando che la lavorazione è invertita
-         EgtSetMachiningParam( MCH_MP.STARTADDLEN, EgtIf( bOpenStart, dTDiam / 2, - dTDiam / 2))
-         EgtSetMachiningParam( MCH_MP.ENDADDLEN, EgtIf( bOpenEnd, dTDiam / 2, - dTDiam / 2))
+         EgtSetMachiningParam( MCH_MP.STARTADDLEN, EgtIf( bOpenStart, dTDiam / 2 + 10, - dTDiam / 2))
+         EgtSetMachiningParam( MCH_MP.ENDADDLEN, EgtIf( bOpenEnd, dTDiam / 2 + 10, - dTDiam / 2))
          -- attacchi e uscite lineari con parte tg nulla
          EgtSetMachiningParam( MCH_MP.LEADINTYPE, MCH_MILL_LI.LINEAR)
          EgtSetMachiningParam( MCH_MP.LITANG, 0)