Dane's FAQs
Torque Charts and Anchor Bolts
Do torque charts for tensioning fasteners apply to anchor bolts?The AISC Steel Construction Manual, 13th Edition has this to say about anchor rod nut installation. “The majority of anchorage applications in buildings do not require special anchor rod nut installation procedures or pretension in the anchor rod. The anchor rod nuts should be “drawn down tight” as columns and bases are erected. This condition... Read more
Galvanizing High Strength Bolts
Can high strength bolts be hot-dip galvanized?Some high strength bolts can be galvanized while others cannot. In the construction fastener industry, typically the phrase “high strength” refers to bolts that have been quenched and tempered (heat treated) to develop the proper strength requirements of a given specification. In many cases, low alloy steels like ASTM A572g50 or F1554g55 are called “high... Read more
Calculating Grade 8 Shear Strength
What is the shear strength of Grade 8 bolts?A common question that we get here at Portland Bolt is in regards to the shear strength of bolts. The shear strength is the value at which the lateral stress on a bolt or screw causes it to fail. It is an important factor to take into consideration when designing structural steel or timber connections.... Read more
Thread Engagement
How much thread engagement is recommended, i.e. how many threads should extend beyond the nut?This is a difficult question to answer. Depending on your application, the answer could be anywhere from 1/2 engagement, up to having two full threads extend beyond the nut. Look at these conflicting answers found in four separate technical publications. Federal Highway Administration, “Guidelines for the Installation, Inspection, Maintenance and Repair of Structural Supports for... Read more
Weight Gained from Galvanizing
How much weight is gained from hot-dip galvanizing bolts?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. However, the AGA goes on to say, “…that figure can vary greatly based on numerous factors. The fabrication’s shape, size, and steel chemistry all play a major role, and... Read more
High Strength Bolts Coatings
What corrosion-resistant coatings are available for high-strength (over 150 ksi) bolts?Due to hydrogen embrittlement concerns ASTM recommends against hot-dip galvanizing , mechanical deposition, or electroplating with zinc or other metallic coatings on high strength bolts ultimate tensile strengths that exceed 150 ksi. So what are the alternatives to provide corrosion resistance for A490 structural bolts? Protective Coatings ASTM states that if a protective coating is... Read more
Bolt Thread Length
Is there a standard thread length for bolts?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. It is important to clearly communicate at time of purchase your desired... Read more
Tie Rod Assembly Configurations
How are tie rods, turnbuckles, and clevises configured?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. Adjustment Adjustments are possible by threading opposing ends of the rod right hand... Read more
Rotational Capacity Testing
What is rotational capacity (ROCAP) testing?Per ASTM F3125 Annex section 2.1.1, the rotational capacity test is defined as a test, “intended to evaluate the presence of a lubricant, the efficiency of lubricant and the compatibility of assemblies.” In a 1970 study referenced by the Research Council on Structural Connections (RCSC), it was shown that galvanizing increases the friction between the... Read more
ASTM Letter Designations
What do the letters at the beginning of an ASTM standard signify?Every ASTM standard is identified by a unique designation. It includes a capital letter (A – G), followed by a serial number ranging from one to four digits, a dash, and finally the year of issue. For example, a common bolt specification is A449 – 07a, although when specified the standard’s year designation is usually... Read more