Material Selection of Armature Shaft
The shaft is a key part of the armature so the quality of the material for the shaft also plays an important role in the whole product.
At present, the mainly used materials for the production of shaft in domestic are the following kind: 20CrMnTi, 20Cr/40Cr and #40/#45 steel.
Among them, 20CrMnTi is a vital material of gear which has a high mechanical properties. After carburizing, quenching and low temperature tempering, the hardness of the surface can reach 58-62HRC, the hardness of the core can reach 30-45HRC. Compare with the other materials, 20CrMnTi is also the most expensive one. The tensile strength and yield strength of 20Cr/40Cr are less than 20CrMnTi and they are always used for making products which has high hardness cores.
As for #40/#45 steel, they are both high quality carbon steel, however the anti-fatigue strength and toughness are not as good as 20Cr/40Cr, also the cost of raw material for #40 and #45 steel is only half of 20Cr/40Cr, so the life of the gear won’t last long if you choose #40/#45 steel to produce it.
We used 20CrMnTi Shaft on our Delco Rmey Cross Starter
By Gzone Michele & Junmiao