Greg's FAQs
In almost all cases, commercially available all thread rod will not meet F1554 grade 36. First, it is rare that distributors or manufacturers keep lot control on all thread rod. In other words, different heats of all thread rod are commingled so that it is difficult to determine the exact certification document that corresponds to... Read more
No, the SAE J429 specification only covers bolts up to and including 1½” diameter. SAE J429 (1999), the specification that includes Grade 2, 5, and 8 fasteners, states: “This SAE standard covers the mechanical and material requirements for inch-series steel bolts, screws, studs, SEMS, and U-bolts used for automotive and related industries in sizes to... Read more
An A325T bolt is a fully threaded version of an F3125 grade A325 heavy hex structural bolt. The F3125 specification is very specific when it addresses thread lengths. Standard A325 bolts have very short thread lengths due to their application as a bolt intended for use in structural steel connections since often it is undesirable... Read more
There are several different thread series available for construction fasteners. Below are the three of the most common thread series utilized in the fastener industry. Coarse Thread Series Unified National Coarse (UNC) – Coarse threads have fewer threads per axial distance than fine threads and a larger thread form relative to the diameter. Coarse thread... Read more
Since the new chemicals (alkaline copper quat [ACQ], copper azole [CBA-A and CA-B], and sodium borates [SBX]) now being used in pressure treated wood have been shown to be up to two or three times more corrosive than the previously used chromate copper arsenate (CCA), the recommended galvanizing thickness for materials being used with the... Read more
Absolutely not! Externally threaded fasteners should never be “chased”. During the hot-dip galvanizing process, excess zinc has a tendency to build up in the threaded portion of a fastener. Chasing threads is a term used to describe re-cutting threads after galvanizing to remove this excess zinc that has accumulated during the galvanizing process. Chasing threads... Read more
Most grade 8 bolts require a permanent marking symbol that is designated by 6 radial lines. However, the SAE J429 specification that covers grade 8 fasteners does not require grade markings for studs (fully threaded rods) or slotted and cross recess head products. Therefore, you will not be able to visually identify a threaded stud... Read more
There are two specifying bodies when it comes to fasteners. ASTM (American Society for Testing and Materials) covers primarily bolts and fasteners for construction applications. SAE (Society of Automotive Engineers) covers fasteners for automotive, machinery, and OEM applications. ASTM A307 grade B is made from a low carbon steel and is a relatively low strength... Read more
These bolts are identical with regard to strength and chemistry. There are very minor differences in the hardness requirements, but the proof load, tensile, and yield strength requirements are the same. From a manufacturing standpoint, we make these bolts using the same raw material and the same heat treating and production methods. Our strength by... Read more
Torque is a difficult value to calculate accurately, especially for construction fasteners and should be used cautiously. The primary challenge is accounting for environmental factors, coatings, and a number of other variables including surface texture, material hardness, and thread series. In most situations, it is challenging to give reliable allowable torque values for bolted assemblies.... Read more
