Ask the Expert

Question: Can threads be chased after hot-dip galvanizing for proper nut fit? Answer: 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 gained during the galvanizing process. Chasing threads will not only remove the excess zinc, but often remove much, if not all of zinc coating and eliminates the corrosion protection on the threaded portion of the fastener. Read More...

Question: What visual markings does a grade 8 piece of all thread rod have that would identify it as being so? Meaning, how can you tell just by looking at a stick that it’s grade 8? Answer: Most grade 8 bolts require a permanent marking symbol that is designated by 6 radial lines. However, the [...] Read More...

Have you ever had a fastener company try and talk you into substituting A193 grade B7 all thread rod for F1554 grade 55 anchor rods, claiming it’s “better?” Have you allowed them to substitute an all thread rod with a nut tack welded in lieu of a headed bolt? These are scenarios that come [...] Read More...

Question: Are SAE Grade 2, 5, and 8 bolts available in diameters over 1½”?

Answer: No, SAE only covers bolts up to and including 1½” diameter. SAE J429 (1999), the specification that covers 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 1½ in. inclusive.” Read More...

When a rod with a nut is substituted for a bolt with a forged head, two issues come into play. In-house mechanical testing performed by Portland Bolt on headed bolts versus rods with a nut, both from the identical lots of steel, the rod with a nut developed up to 12% less strength than the comparable headed bolt. Read More...

Question: How much weight is gained from hot-dip galvanizing bolts?

Answer: According to the American Galvanizers Association (AGA) the weight of an item on average will increase about 3.5% from the zinc added during the galvanizing process. Read More...

A summary of corrosion resistant coating options for high strength bolts. Bolts with an ultimate tensile strength higher than 150 ksi can not be hot-dip galvanized. Here are some alternatives. Read More...

Question: What are the main difference between ASTM 307 GR.B, ASTM A449, and SAE Grade 5 bolts?

Answer: 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. Read More...

Question: Is there a standard thread length for bolts?

Answer: Depending on the type of bolt you are using the thread length can vary greatly. There is not an inclusive thread length standard that covers all fasteners. Depending on the applications, manufacturer, and a number of other factors the amount thread may change. Read More...

Tie rods, clevises, and turnbuckles are an important part of many architectural designs. Canopy supports, structural steel bracing, and walkway hangers are a few of the applications that use these assemblies. The unique configuration allows for field adjustments in both length and tension. Read More...