Pins come in an assortmant of sizes ... the outside diameter determines the size and threads per inch ... Most common are 5/16x18 , 5/16x14 , 3/8x10 , 3/8x11 , 3/8x14, and the radial pins...Some cue makers have a slightly different thread they either make or have made... The larger pins with a flat face wood to wood joint in my opinion is the strongest and has the best feel ... I have used all the above and my favorite are the 3/8x10 or 11 and the radial ... stainless , brass, aluminum or G-10 are the different materials the pins are made of, and which you use, usually is determined by how you want the cue balanced , forward or butt heavy or somewhere in between...Go to Atlas Billiard Supply and scope their selection of pins and note the weights of each ... not cheap either ... Cue building is expensive but fun ...Hope this helps some ...