What’s up guys? This is Michael with Michael Talks Metal back for a little lesson in steel. Today we’re going to talk about some of the terminology, acronyms, and abbreviations used in describing steel mill products. If we want to buy or sell metal and engage in conversations regarding such topics it helps to know the jargon, the nomenclature, the lingo. Today, we’re going to help you do just that.
2 IN RD 4140 HR ANN BAR is a string a customer could give you or you could give a vendor when looking for material. Seems simple enough, right?
Let’s take it apart and see what we know and some things that we might see as well.
First we have a number which corresponds to a size or dimension – in this case it’s 2 and then followed by the letters IN, that “IN” is a unit of measure – Unit of Measure could be shown as “UOM”. Then another 2 letters which are another abbreviation for the shape. In this case “RD” for round. But we could also have metric units for size like “mm” for Millimeters. Here in the crazy US of A we like to function illogically and NOT use the metric system, that’s another topic of conversation. More shapes can be SQ for square, HX for hex, and multiple dimensions for a rectangular section RT .
Next in our example, we have the “Grade” or steel alloy specified as 4140. This is where things can begin to get more complex. We can add a prefix E and now E4140 has a different chemistry limiting S and Phosphorus to .025 % max.
Insert an L in 4140 and 41L40 is an alloy that has lead added to aid its machining characteristics. L stands for the added lead.
Add H as a suffix and 4140 H is an alloy that has limits to the heat treating response
H stands for the Hardenability band requirement. 4140 RH for a Restricted Hardenability requirement.
Insert AQ for aircraft Quality or BQ for Bearing Quality after 4140 and we have added restrictions for the internal cleanliness and testing .
Next in our example we have HR, indicating that the surface condition allows the scale typical of the hot working temperature used to produce the bar at the mill.
Change it to RT or HR RT and it means the bar has been rough turned to remove the scale.
Next we have ANN for Annealed as a heat treated condition and could be followed by a range or maximum hardness. Additional descriptors like LP and SPH indicate restrictive types of anneal.
Change HR ANN to HRAP and Hot Rolled, Annealed, and Pickled is condensed into these four letters. Pickling is an acid scale removal and with hazardous waste concerns has been replaced by abrasive descaling. Instead of ANN, we could have HT for Heat treated or Q&T quenched and tempered to indicate hardened conditions. Hardened conditions would need a hardness or strength requirement as well.
And of course our example is missing some further information like the length? Want to hear more? Tune in for more examples to talk about next week so stay tuned.
Our example today assumes there is no specification attached and the description stands alone. Additional specifications and part requirements can alter what we have shown you here today
SO CHECK THE SPECS !!!!!!!!!!! And visit us at our website www.michlinmetals.com thanks for watching. This is Michael with Michael Talks Metal, see you next Thursday, 10am! I’m out.