Earnest has provided Plow Bolts to the industry, since 1948. In fact it was the first product that our founder, Paul Earnest Zehnder, sold. Plow Bolts launched Earnest into the industry and since that time, we’re proud to have developed the knowledge and expertise our customers rely upon. For instance, while your customer may not be too concerned with the relation between tensile strength and shear loads, we are. For over sixty years, we have provided the highest quality Plow Bolts that meet exact specifications.

Our E8 Plow Bolts are manufactured with the precise balance between strength and hardness that meets the SAE J429 specification. This is not the case with all Plow Bolts. Some manufacturers adjust properties to achieve different results.

Let’s take the A9 for example. When compared on a dimensional basis there is no difference between the E8 and A9 products. The threads, diameters and lengths are the same, and the same sized bolts will fit the same applications. However, they will perform and deliver differently.

The A9 bolt deviates from the SAE J429 standard most notably with regard to heat treatment. This deviation creates a hardness level that does not meet the recognized specification. While the intent is to create a harder bolt, the process causes the bolt to become more brittle and the ductility of the bolt is sacrificed. In any application where impact forces are encountered, ductility is more important than hardness in avoiding brittle fractures.

All Grade 9 bolts (A9, F9, L9) are non-standard designations. Subsequently the head markings used (nine radial lines) on the bolt indicate non-conformance to the SAE J429 standard. In some applications this may be a non-issue. For safety sake, Earnest strongly recommends the use of SAE J429 conforming parts in every application that may encounter high impact stresses. When it comes to A9 VS E8, less is definitely more.