screw for bed levelling

This is an simple screw for bed levelling,

you can use this m3 screw like this:

https://www.amazon.it/195-PCS-M3-dadi-esagonali-esagonale-acciaio/dp/B00NQCP1S0/ref=sr_1_18?adgrpid=62276531896&gclid=CjwKCAjwpuXpBRAAEiwAyRRPgXY_8UofyLxPidE96IzEMbg7ipQLB51nbU-QDwQ8p0dv63ffyBSKvxoCTG8QAvD_BwE&hvadid=311369085109&hvdev=c&hvlocphy=1008736&hvnetw=g&hvpos=1t1&hvqmt=b&hvrand=16871669780164258889&hvtargid=kwd-522501129332&hydadcr=13518_1760549&keywords=vite+m3+esagonale&qid=1564068193&s=gateway&sr=8-18

* 02-03-2018 UPDATE V2 with larger diameter