Could somebody please let me know what the bolt sizes mean. Basically I have to replace some old allen bolts with stainless ones after spending 2 days drilling and grinding the old ones out. The old ones fit a 6mm allen key and are 45mm long Does this make them m6x45? any help appreciated Thanks
The bolt size is the diameter of the thread & not the size of the head or spanner across the flats. It was more confusing when a 1/2" whitworth bolt used a 7/16" whitworth spanner.
you will probly find that the bolt you are descibing is a 8x45 8mm being the diameter of the thread one easy way to tell is to have a small range of spanners say 5 to 10 mm and just use the open end to get the thread diameter size hope this has been of some help to you......