Shoulder Screw or Idler Post
5mm or 6mm shaft should screw known as idler post
Except IPP-6_16 is mold steel, all other should screw is made of 304 stainless steel (SUS304)
5mm shaft should screw with M4 screw and 6mm shoulder screw with M5 screw
It was proved that the idler post works better with ball bearing equipped idler pulley or roller bearing and its Press Fit. You may need tools to fix it.
Applications, CoreXY 3D Printer Prototype Use.
New supply 4mm idler post with M3 screw.
Shoulder bolt is also known as shoulder screw, stripper bolt, or stop screw which can be used to work with flange ball bearing or ball bearing as idler post.
Idler post means the axis or shaft is a slave shaft, the bolt itself is just working as a post that is steady, but the idler will spin together with the drive shaft. The drive axis is connected with the slave axis using a timing belt or v-belt, chain, and so on transmission parts. Idler can be ball bearings or timing pulleys with ball bearing press mounted.
Shoulder bolt in fact it really owns two shoulders. The first one is the socket hex head to the main shaft or the post part. The second shoulder is the post shaft to the mounting screw, so if the shaft is 5, as usual, the screw will be M4.