Newest FAQs
Concerns Calculating Torque
How do I calculate torque for construction fasteners?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
Hex Bolts vs. Hex Cap Screws
What are the differences between a hex cap screw and a hex bolt?These terms are often incorrectly used interchangeably. The most basic difference between a cap screw and a bolt is the way in which these fasteners are installed. Technically, a bolt is installed by turning a nut to tighten the fastener, while a cap screw in installed by turning the head of the bolt to assemble... Read more
Lag Screw Shear Strength
How do I determine the shear capacity and strength of lag screws?Unfortunately, we have no specific data to answer this question. First, “standard” lag bolts that are readily available in the marketplace are ungraded, meaning they are not manufactured to any ASTM specification and have no verifiable mechanical requirements. Therefore, it is impossible to determine the strength characteristics of a lag screw unless they are custom... Read more
Grade 55 Steel Properties
Can I use ASTM 108 Round Bar, a CF-1018 round bar, for F1554 Grade 55?The problem with ASTM A108, 1018CF is that there are no mechanical requirements and typically the test reports that accompany this steel reflect the chemistry only and not the strength of the steel. Test reports will need to accompany this material that reflect all four of the values listed below, and these values will need... Read more
Malleable Iron Washer Details
What are the purposes for the different components in malleable iron washers (MIW)For many years a malleable iron washer has been a common component in heavy timber and marine construction. With a large bearing surface and thick cast design they help prevent the bolt head or nut from pulling through wood connections. There are two common types of MIW. One style of malleable washer is produced in... 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
Grade C Eliminated From ASTM A307
What happened to ASTM A307 Grade C?One change with regard to specifications that will have a significant impact on the construction fastener industry is the August 2007 elimination of the grade C designation within the ASTM A307 specification. ASTM A307 is the standard specification for low carbon steel construction fasteners. Until recently, A307 had three grades A, B, and C. Grade... Read more
SAE Grade 8 vs ASTM A490
What are the differences in strength and application between SAE Grade 8 and ASTM A-490?In some respects SAE J429 grade 8 bolts and ASTM A490 bolts are similar, and in other respects they are different. The first thing to address is the fact that these specifications are covered by different organizations. SAE (Society of Automotive Engineers) covers bolts for automotive, equipment, and OEM applications, whereas ASTM (American Society for... 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
Metric Bolts – We Convert
Do you manufacture metric bolts?All bolts we manufacture are made to imperial measurements. The primary reason for this is because the steel used to make bolts is milled to imperial sizes. Even though metric measurements are almost exclusively used internationally, most raw materials are only available domestically in inches. Often projects, such as highways, bridges, and power plants specify... Read more