CHAPTER XIII 



Plow Bottom Metals 



THE farmer is often in doubt as to whether he should 

 use a chilled or steel plow. A knowledge of chilled 

 and steel metals as used in plows will enable a farmer 

 to determine for himself which type of plow he needs. 



In steel plows of the best grade, the principal wearing 

 parts, the mouldboards and shares, are made from what 

 is known as soft center steel. This steel is composed of 

 three layers fused together. The two outside layers are 

 very high carbon to insure hardness. An extra hard 

 finish or temper is necessary to make the plow scour. 

 The center layer is of low carbon to impart toughness 

 to prevent the breaking of the brittle outside layers. 



Steel plows thus made are successful for use in soils 

 for which they are adapted. The mouldboard of a steel 

 plow of the type described is only a quarter of an inch 

 thick and the grinding and polishing necessary to finish 

 the surface added to the natural wear, of course, wear 

 away much of this thickness so that sometimes the soft 

 center becomes exposed and the plow will no longer 

 scour. For this there is no remedy and a new part is 

 necessary. 



While steel plows are, as a rule, lighter in weight than 

 the chilled, when it comes to the matter of draft the 

 chilled plow is by far the lightest in any or all soils for 

 which it is adapted. The draft of a plow is determined 

 not so much by the shape of its mouldboard and style of 



