Actually, 10 Nm (torqued dry) is ~75% of proof load for an M6 8.8 grade bolt.
If you lubed the thread and torqued to 10 Nm, you've reached proof load, give or take.
http://www.cncexpo.com/MetricBoltTorqueNm.aspx
Useful to keep in mind when torquing various bolts with unspecified torque: ~10Nm for M6, ~25Nm for M8, ~50Nm for M10, ~90Nm for M12.