Here is some data on nut and bolt grades. It becomes pertinent when Nissan proclaims a bolt or nut, a one use item! What it actually means is Nissan has cheapened the part to the point where using it more than once (retorque) could bring its integrity below industry standard (axle nuts)(bearing hub bolts) etc. since Nissan charges 5x grade 8/12.9 prices for a grade 2 nut and bolt. Consider going to a nut and bolt store for grade 8 sae nuts and bolts to replace the substandard Nissan fare, or metric grade 10.9, 12.9 if the bolt/nut is purely metric in stature.