The way i understand it from purely theoretical sources m2 is a high temperature tool steel high speed steel while d2 is borderline between cold working and high temp.
M2 tool steel knife.
World wide the m2 type is by far the most popular high speed steel having replaced t1 high speed in most applications because of its superior properties and relative economy.
M2 high speed steel is by far the most popular high speed steel replacing t1 in most applications because of its superior properties such as its bending strength toughness and thermo plasticity all of which are higher than t1 by 50.
Keep your blade oiled as d2 is prone to rusting and corrosion.
There s no doubt h1 is a specialty steel.
When we call a normal steel stainless it.
This is one of those most ubiquitous steels in knives.
The m2 steel is a great steel but for knives it s not the best i personally wouldn t recommend maybe i would if we were in 2005 but we re in 2020 there re better steels with much better performance and lower price but if you ever got the chance to have m2 knife as gift or your dad s knife leave us a little review or your opinion on it in the comments below as i always say i.
M2 high speed steel.
Both exibit increase in hardness with increase in tempering temperature unlike your regular cold working steel where hardness drops monotonously with increase in temperature.
A2 is a mid range air hardening tool steel it s known for its good toughness its tougher than d2 steel or m2 steel and it has a wear resistance in between o1 steel and d2 it s used for punches and dies chuck jaws cutting tools for woodworking tooling for plastic injection dowel pins hammers industrial knives and gage.