"I recently purchased 50 of these for a large house job from somewhere else when my local screwfix sold them in 10's for the same price per unit as i paid for 50's. So one up for screwfix!. Quality is good they take a hammering which is good and the locking bolt doesnt faulter under the pressure of hammering in or when tightening up. If was was to say a down side would be when using for timber wall plates as i was then it would be nicer for a larger washer; but found some square washers 75mm by 75mm that worked well with these. would recommend to any one I used the 120mm bolts as well same applies"