What Does 4140 T Steel Plate Mean ? The “T” in 4140 T Steel Plate usually stands for “tempered”. It means that the 4140 steel has been done by heat treatment process called quenching and tempering (Q+T or prehard).

Here’s a brief explanation about this question:

AISI 4140 steel is an widely used alloy steel that contains chromium, molybdenum, and manganese etc. After the 4140 steel is initially rolled, we need to do quenching and termpering to achieve higher properties for different applications. This process is to heat the steel to a high temperature and then cooling it rapidly by sink 4140 steel plate or round bar in a liquid, often oil or water.

This rapid cooling process makes the 4140 steel material very hard, but it also makes it brittle. To release this brittleness, the 4140 steel is then tempered. Tempering process is to reheat the quenched AISI 4140 steel to a lower temperature to allow some of the hardness to be exchanged for increased toughness or durability.

So, when you see 4140 T Steel Plate, it means that you’re looking at a steel plate made of 4140 alloy steel that has been quenched and tempered to achieve a better balance of hardness and toughness. This kind of 4140 steel is often used in applications where strength and durability are paramount.

We Otai can supply you both 4140 plate T and 4140 plate A or as rolled. Please contact us for any further questions.