Shank is 1.25mm or 0.049.5 inches in diameter using a caliper. Up for sale is my version of micro-needles. I made them with a Presto shank, but the tip is a smaller triangular tip, giving out more thinner grooves. I have tested these and they sound good enough to list them . You can cut into lacquer, vinyl, acetate, and even Solo plastic pie plates with these. I have even heard you can turn the needle backwards and emboss onto polycarbonate but I have done no tests to support this theory. These can be used in all cutters like Recordios and Recordettes (suitcase cutters), plus Presto/Grampian cutters as well. If using a suitcase cutter, and you want a shorter shank, then you can snip some off the flat end of the shank with a pair of pliers, using another needle for measurements. These needles can also be heated as they are stainless steel. They are NOT glued together, but each needle is one piece. It takes more effort to make these needles so my price is a couple dollars higher than my other needles sold . Be sure to check out my other listings as well. Thanks!!! If my ad stops as a result of all needles sold in this listing, I will re-start it as soon as I produce more needles which shouldn't take long.